I did adjust the gain, but has been recommended here on several occasions, I decreased on the high freq points as opposed to increasing on the low freq points. Right now I have all sources running in Jazz mode with the exception of the DVD player during movies and I'm running it in theater mode. Now if I could just get those discrete codes, I could automate it all through macros on the PronoPro and giggle myself silly.

Mr. HiFi -

Tell me more about your interest in doing a FR plot by hand. What would you be trying to achieve? Would it be just to verify the accuracy of the DD RTA readout, or something else. How would you take the measurements? With an SPL meter and fixed tones at particular frequencies?

I also have a fairly sophisticated RTA program installed on my laptop, and one of these days I will take the time to compare the results of the DD to it.

- hifisponge

I used to use a sweep generator to plot frequency vs amplitude using a calibrated mike/sound level meter. The output of the sweep generator ramped frequency and simultaneously fed a corresponding voltage to the x axis of a plotter. The output of a sound level meter fed the Y axis of the plotter. When you're finished you wind up with a pretty good idea of the excited frequencies in your room. I would be curious to compare this to the DD15's output to understand the smoothing and assumptions the Velodyne engineers made in order to make such measurements usable to the public. I say this because I never had any luck trying to perform bass frequency adjustments in small rooms. In auditoriums or concert halls or outside it works very well.

I am going thru the setup issues myself and waiting for delivery of cables before final efforts.

I have found that the DD's can really shake the house and make walls and other things move. So the suggestions about doing the calibrations at lower volumes makes a lot of sense. Somehow, adjusting for the resonate responses of moving walls does not seem like the right thing to do. Acoustic response is one thing, structural response is another.

Bruce,

Thankyou for your explanation. I tried listening for the "noise" but did not hear it. I thought I knew something about Acoustics having taken several physics courses on the subject back when Dynosaurs ruled the earth but for the life of me I am unable to figure out the figure od merit you describe in your statement "The loop gain (that is, benfit from the servo system) is actually measured in dB, in this case about 30 dB, but we translate it to a numerical figure for ease of understanding, and it amounts to about 3500 cone corrections per second." How does one go from gain to frequency? Anyway, I really appreciate the information. I pictured an accerelerometer physically attached to the cone. The piezo-electric element seems to achieve the same measure although i can not figure out where you place it. Mine sounds superb and obviously it works. I was unaware that anyone else is us using servo feedback to control low frequency non-linearities.

Originally posted by MrHifi
Bruce,

Thankyou for your explanation. I tried listening for the "noise" but did not hear it. I thought I knew something about Acoustics having taken several physics courses on the subject back when Dynosaurs ruled the earth but for the life of me I am unable to figure out the figure od merit you describe in your statement "The loop gain (that is, benfit from the servo system) is actually measured in dB, in this case about 30 dB, but we translate it to a numerical figure for ease of understanding, and it amounts to about 3500 cone corrections per second." How does one go from gain to frequency? Anyway, I really appreciate the information. I pictured an accerelerometer physically attached to the cone. The piezo-electric element seems to achieve the same measure although i can not figure out where you place it. Mine sounds superb and obviously it works. I was unaware that anyone else is us using servo feedback to control low frequency non-linearities.

Hi Art,
I have a picture of the accelerometer mounted on the voice coil, but I can't seem to post it up here. PM me and I'll send it to you.

In addition to the speaker leads, we also have a 5-lead accelerometer cable that attaches to the driver assembly. The piezo element is sealed in a case and is very sensitive. There are electronics inside the case that A to D the piezo's signal before it goes trough the cable to the DSP. We've tried other servo systems but this is by far the best in our experience.

See you,
Bruce

Curt, any word on a pronto .ccf file with discreet on/off, etc?

John

Hi John,
Should be very soon. Within a couple of weeks we hope.
Curt

I have three questions about calibrating my DD18.

1/ My receiver (Denon 5800) has a fixed THX 80Hx Xover.
The DD-18 manual states I should set its crossover to the same as the receiver. A little piece of paper that comes with it says for THX certified operation I should set the Xover to 199. What motivates the conflicting advice? Which should I do? What are the tradeoffs?

2/ If I calibrate my DD-18 to have a straight line at the crossover, then when I check the level using a RadioShack sound meter and Digital Video Essentials 6.1 levels, the sub is 10 dB down. Raising the sub 10dB then results in a downwards slope at the Xover. Is this normal? Is a possible explanation that the (uncalibrated) RS meter may be under-measuring the bass? For reference listening (as the mixing engineer heard it) where should I put the DD18's level?

3/ There's some advice in the manual that says because our hearing is less sensitive to bass, we might try boosting the DD18 volume 5 dB or so. Would this be a straight 5dB rise across the board, or should we equalize to get a constant downwards slope 15-80Hz, or some other (average hearing adjusted) curve?

Thanks.

If you want to use the RS SPL meter to calibrate you will need a CD compensated for use with the RS analog meter such as:
http://www.rivesaudio.com/software/softframes.html. You can also download the "instructions for use" and use the compensation values in the chart if you don't want to purchase the CD. And yes, the calibrated setting for my system was also down a few db from the 75db test tones in my receiver, but I think this is normal.

Dave,

If the processor sub out has a crossover, the one in the DD-18 does not need to be used. Setting it to 199 turns it off. This is in the manual somewhere. Two Xovers overlapping can cause some problems in some situations. You only need one. Future DD series software may change the video interface to have an 'OFF' setting instead of setting to 199, but thats a cosmetic change that will not alter how it then works.

The calibration process is used to get rid of some of the lumps and bumps in the room response. I don't think the level is that critical. With different music you will want to adjust the volume of the sub. When you do that the low end of the spectrum below the Xover point will lift or fall and the gross room errors will still be corrected. So you will be making such adjustments to suit what you are listening to. So the absolutes that you are struggling perhaps don't have much significance in the end. Things become more comfort level and less technical.

Some have cautioned on this BB to not get too carried away seeking perfection. Wild settings in the EQ that look flat response might sound not so good. You are calibrating with steady state tones for all intents and purposes, even though its a tone sweep. Getting that flat might be sub-optimal (sorry about the pun), as the response of a bass strink pluck or drum hit might be different. So read prior posts on this. Standing waves in the room response do not go away when you EQ things. Creating a hole in the music is not a good alternative. You have to live with what the room does to some extent. Setting EQ with high volumes will then be playing around with the resonant responses of windows, walls and floors. Better to EQ at levels where the structure is not too active.

As for point #3, again you will set the volume to what sounds right, so no problem.

And just for fun, after you think that the calibration is technically very nice, try putting the microphone someplace else. A change of a couple of feet can make things change a lot. I am still learning and reading myself.

(What software version in the DD-18? Affects the default turn on preset. Newer software turns on in preset 4=music.)

2 DD-15s in stereo mode, RS232 ganged, driven with amp outputs
CJ PV-15 VAC tube preamp, teflon inteconnects to
Aragon 8008 Amp biwired to
Magnepan IIIa's
7" DVD player for DD-15 video output monitoring

Originally posted by curt c
Hi John,
Should be very soon. Within a couple of weeks we hope.
Curt
Great! Just in time for my new dedicated space to be done. :)

John

Dean,

Thank you for restating the reality of room equalization. I have tried several times in this thread to explain the fact that if you boost and cut various frequencies using the equalizer, the result will probably sound worse than leaving the equalizer flat or dropping it out of the signal path.

Regarding your point about using the internal HF filter in the Sub--I own both a Pioneer Elite SP-99D and a Sony ESP9 Doby Digital preamp/decoders. Both of these have filters on the LFE channel that roll off the frequencies above 120Hz such that the response is down 3dB at 120 Hz I agree that ideally this would be the only filter in the LFE channel signal path. In my system I tried to set it up this way but the hum was so high that I was forced to switch in the filter. Recently, I put in a 3 prong adapter on the AC plug to lift the ground connection as suggested by one of the Velodyne guys on here. It lowered the hum dramatically but I can not getto the switch on the back of my FS1800R that switches off the low pass filter. I will let everyone know if there is a perceptible difference. Oten the measurable is inperceptible to the human brain. No doubt that the hum went down but not sure whether anything else has improved.

Switched off the low pass filter which was set at 80Hz. They must include a lot of 80Hz to 120Hz material in the LFE channel content because now there is quite a bit of undesireable interaction between the sub and my VMPS and EV spkrs. Nevertheless, the most interesting thing is that when the DD LFE indicator lights on the decoder, somethhing always comes out of the spkr. This was not the case with a setting of 80Hz.

Will I finally placed an order for the beast.:D

Now I have to locate a good Structural Engineer to make sure my house can survive.:(

John,

I have nail pops everywhere caused by the sub.

Art,

Thanks for the good news!!!!!!!!! I recall that after the 94 earthquake there were a few nail pops in some areas.
Looks like I may have to go over the critical areas with dry wall screws.
Of course I could just keep the SW level down:(

http://www.avtalk.co.uk/forum/index.php?t=msg&rid=0&SQ=0&th=2501&goto=30984
nuff said.

cajunlab,

I saw your photos a few weeks ago on the UK Forum. Real Nice!

"Water damage, improper ventilation & age"........good excuse for your DD-18 :D

I posted the following in the general speaker forum & got no reply. Any ideas from this group?

Due to wife's demand to clear up the room, I'm thinking of replacing my current large tower speakers with small on-wall speakers (Paradigm OW-Monitor 5), with the bass handled by Velodyne DLS-5000R. My room is 2000 cu ft. According to the Velodyne product recommendations on their web site, the sub is 1 or 2 sizes larger than I need, but I figure you can never have too much subwoofer. I will get a Denon 2805 to drive the system, 100 watts/channel.

My concern is that I want to mount the subwoofer in my equipment cabinet, specifically the center bay of the 3 lower bays of equipment in the attached photo (I'll remove the glass door of course!). The DLS-5000R just does fit, pretty much filling up the center bay. Two questions -

1. In this location, the sub won't have the bass reinforcement from a corner location. Seems like I still have plenty of bass with this sub - true or not?

2. How do I isolate the vibrations of the sub from the rest of my equipment in the adjacent cabinets, and the plasma TV above? Is there some kind of serious vibration isolator, say a viscoelastic pad, that I could mount the sub on?

Max

mgamon -

1. Yes, in a 2000 cu. foot room, a 15 incher should be more than enough sub, even without corner reinforcement. I have a DD15 in a 2400 cu foot room that is permanently open to a room of equal size and I have no complaints. The larger concern with your plan is that placement of a sub is critical to its sound quality. It's a coin toss as to whether you equipment cabinet is the "right" spot.

2. You could try isolating the sub from the equipment cabinet with Vibrapods (http://www.vibrapod.com/) or an Auralex GRAMMA pad (http://www.auralex.com/sound_isolation_gramma/sound_isolation_gramma.asp), BUT keep in mind that the transmission of vibrations from the sub cabinet to the equipment cabinet are likely to have less effect than those caused by the sound wave its self. That is, you will be placing a speaker that reproduces loud, low frequencies right next to your other components, so isolation may have little effect. For that matter, when I first installed a sub in my system, I had to track down and tack down all sorts of things that were buzzing in the room, regardless of sub location.

Good luck,

- Tim

Tim -

Thanks for the links. I knew there had to be something out there. Still, like you say, probably not the greatest idea to put powerful sub right next to electronic gear. Sure would make it easy to connect wiring though.

Max

Max,

My current Subs are part of the L/R speakers next to my equipment cabinet (see attached photo) and even with some isolation, I can loose optical tracking with my DVD and CD players.
I also have another Sub (to be replaced with the DD-18) in another area of the room and by itself will not create any problems.

After downloading and reading the manual, I have a DD-18 coming !
What sold me is the COMPLETE versatility/tunabilty of it.

I will use the DD-18 with my full-range mains for 2-channel, and use it along with my Contrabass for HT. The fact that I can use the DD-18 to EQ for the combined LFE of the Contrabass + DD-18 is really cool !

I also have a TacT RCS 2.0S on hand to help validate/measure the end result too. I hope to eventually start a new thread with lots of graphs and measurements.

- Andy

Quantaphrenia!!!!!!!!! I used to do the same thing until a musician friend told me that my perfectly adjusted/equalized system sounded awful. It did.

I used to own a TacT 3 years ago, and honestly, I did not like what it did.
With this latest updated TacT hardware & software, I will use it very "mildly".
It can also function as a "simple" digital parametric EQ, without using the full Frequency & Time correction. But that is a story for another thread.

- Andy

Originally posted by Dean_KS
Some have cautioned on this BB to not get too carried away seeking perfection. Wild settings in the EQ that look flat response might sound not so good.

Dean,

Thanks for the advice.

I thought I'd recount my experiences in tuing the DD18.

I have the eq dialed-in pretty flat. Here is the net result:
http://members.rogers.com/ynnepd/dd18/dd18eq.gif
(processor x-over is 80 Hz).

My method was as follows:

I first moved the sub around to each of the four places in the room it would fit, and see where the line is flattest. I tried placing the sub at the listening posiiton and moving the mic, but that gave different results (because my seats are built-in I could not get the sub's driver to closer than within 2 feet of where my ears would have been). Differences in location where dramatic. Here is the sub in the worst position:
http://members.rogers.com/ynnepd/dd18/dd18badpos.gif

Here it is in the best position (of the 4 I had available):
http://members.rogers.com/ynnepd/dd18/dd18goodpos.gif

In each location I tried moving the sub around a bit to flatten the line as much as I could.

The best location turned out to be as far back into the front left corner as possible. Oddly, the front right corner was much worse (the room is symmetrical, but the furnishings and equipment rack aren't quite).


Then I moved all the eq's to the far left and turned them all off. Then, I garbbed the first eq, moved it to the center of the biggest problem, and played with the level , Q, and freq until it was as flat as possible. I did this using a "local search" algorithm: I moved the level down a notch, and asked if the line was flatter or not. If yes, I moved it again. When I was at a local minima (wherever I moved, up or down, it got worse), I then did the same thing with the Q, and then to the exact frequency. I then cycled back to the level and Q, and so on. Eventually, I got to the point where a move in either direction of the level, the Q, or the freq makes the line less flat.
Then I played some music, and compared eq on and off.

Next I moved the next eq to the next problem and then I adjusted Q/level/freq until it too was gone. Then I played some music to make sure it did not get worse. I remembered the level of eq2, and A/B'd music with eq 2 set to 0 and where I adjusted it to.

I found I needed 6 eqs to get things almost perfectly flat. On each audition, things never got worse, and the net result was better than with no eq. Eq 1 was the most dramatic (Eq #1 is the 3rd from the left in the picture) - it removed the boominess that I'd heard ever since I set up this room, so that was great. With the boom at ~30Hz gone, I found I could raise the overall bass level to what I liked and seemed consistent with live performances without having the boom invade.

Eq 2 was an improvement as well, but more subtle. I heard cleaner pitch definition on plucked jazz dbl-bass (Eq #2 is the 2nd from the right). Eq 3 helped at the x-over - I found I got a better blend of the center speaker with the sub (Eq#3 is far right). Mind, this was a compromise as the x-over flatness was different depending on if the tones were played through center channel, LR, or all 7 speakers. I only noticed the difference on test materials, though (a swept tone around the x-over).

I can't say I heard it getting any better on eq 4-6, mind, which bears out Dean's point, but I did not hear it get any worse either (probably because the adjustments on these eqs were smaller). On the other hand, the flat line at my listening position makes me feel warm and fuzzy. As Dean says, just don't move you head a foot either way, sit anywhere else, or open the door!

I used eq's 7, and 8 to boost 15Hz to get that little sag at the low end up (had to boost 15 and then cut 18 to flatten it again). The sag is gone now. This boost helps with Telarc's new SACD 1812 overture cannons (there's a huge long rumble at the end of some of the shots you miss without a lot of 15Hz boost), and it helps with movie special effects (e.g, helicopter blades whooping around at 10Hz-18Hz in "Blackhawk Down") - and since there's nothing else down there that you need to be particulary accurate about...)

I did use boost at 15Hz and elsewhere, but I have no worries about headroom - my room is small and sealed (1500 cu feet) and the overall level of the DD18 that I feel is most natural (after doing all the adjustments) is only at 20. I can crank it up to 50 or so and still not run out of headroom (which is unbearably bassy).

All i can say is--How can you stand listening to it? You have fallen into he Equalizer trap.

I tend to agree with MrHifi; I would try for a ± 3 or 4dB rather than for a perfect-looking flat response. I would love to listen to it.

Val

I don't use any EQ with my DD, it sounds much better IMO.

Like everything in life too much of anything may be bad for you. In this case the most important thing is getting rid of room modes from what I've read. Which means reducing the major bums/peaks/spikes in room response usually referenced to about 80db level. I have found that setting my Integra 8.2 to Stereo/PCM with sub and all speakers to small for DVD Video/Audio and SACD that I can get much better adjusted response and sound with no equalizer in my system. I used this CD: http://www.rivesaudio.com/software/softframes.html and an RS SPL analog meter. I moved my sub to a location with only one major spike, adjusted the crossover and level to be as flat as possible with 1KHz 80db as reference.

It doesn't sound like doing much but the difference it made was immediately noticeable in the upper frequencies, the entire frequency spectrum from top to bottom benefited.

I think MR. HiFi is on to something here, in other words you shouldn't eq your setup to death.

None of us know Dave Penny's final sound in his room/system except that he is exceptionally happy with it. So let's not criticize his EQ choices as we do not know what he is up against with his room. Also he is only EQ'ing < 80Hz signals, so is not screwing up the mid & treble spectrum a-la classic cheap analog graphic EQ. I like his method of adjusting AND verifying each adjustment by ear ... in other words -> do no harm. Thanks for the setup tips.

- Andy

Clubfoot,

You have benefited by limiting your LF response to one source. In my experience , this decreases muddiness in the sound and increases "aatack". This works in relatively small rooms and is the technique employed by BOSE in their demonstration rooms. If the cutoff is low enough, the system probably sounds wonderful.

My own system uses VMPS STIII speakers in the front and Electrovoice STIII's in the rear. I use a mid '90's Velodyne F1800R Subwoofer for the LFE channel only. I rarely use it for listening to music because the other 4 channels use a total of 4 15" LF drivers and a couple of 12" and 4 10" drivers to cover the low end to 17Hz. All attempts to equalize small to medium rooms over the years using equalizers with variable q and center frequencies has never provided realistic sound. Makes sense if you think about it. Speakers in this category have free air respnses that +/-5dB 20-18K. That kind of source response should not be fooled with IMHO. If you have a room that is extremely live or dead, an equalizer or tone control can help but only if used in moderation. under no circumstances should one believe that a flat room response line provides realistic sound. i think any acoustic engineer would agree. Fact is most live events peak up/sweeten the HF response and decrease bass in order to prevent feedback.

HiFi,

Thanks for the comment, my room is about 2400 cubic feet and to clarify I don't presently own a Velodyne but do intend to purchase one in the near future,...that's why I'm here in this group. My main speakers are Energy Veritas 2.4s and in my room they go well down to 20Hz using the previous method of measurement, but because of room resonances at 40Hz, 80Hz, you get my drift, they sound much better using my present Definitive Tech sub that has limited response below 25Hz. I'm looking forward to the day I finish my basement home theater with free reign to do as I please, acoustically. With your setup I can see/hear why you would not require a sub, with four full range channels, a much better proposition for listening to multichannel audio.

We do agree on one thing and that is the sub woofer response affects how the mid and highs sound in terms of balance.

Originally posted by MrHifi
All i can say is--How can you stand listening to it? You have fallen into he Equalizer trap.
What nonsense.

To my ear (and I am a musician - a 'cellist used to discerning frequeny differences) withut eq, and in my room, pitch definition is lost without the eq. All notes in the lower dbl-bass and low tympani range get pulled into a mono-frequency blob.

As well, without eq, there is a drop-off in the lowest frequencies (<=18Hz) that results in certain movie special effects losing their impact.

The smaller adjustments, used to flatten the line, I could not hear any difference (positive or negative). But setting them to 0 is not going to clean up the signal path in any way whatsoever (those big bad digital signal processors will still do their work, either way - only the math changes).

What I cannot stand is listening to a sub at a natural level, and yet have the sound dominated by some room modes.

The eq is a wonderful solution to this, and to the problem that subs are not flat as far down the frequency scale as one would like them to be.

ynnepd,

"(<=18Hz)"

My friend, no sub or in fact any speaker I know of puts out anything one can hear or feel below 18 Hz. Sustained LF reproduction in this range will make a human and most apes throw up or become quite ill. The speaker excursion and shear size of the piston area required to produce perceptible tones makes reproduction in this range impractical. My VMPS Super Tower III speakers are 7 ft. tall and use several 15, 12, and 10" active drivers with a 15" mass loaded and adjustable passive driver to achieve an advertised
17 Hz -3dB LF. In fact, in my listening room, which is 62 ft long, 17 ft. wide and 8 ft. high, I can barely perceive anything at 24 Hz when the SPL meter reads 80dB at 400 Hz.

FYI: When using my Granite Audio bass test CD to evaluate my mains, my skull feels very wierd at the 22 Hz tone ! :)

Clubfoot, I am in nearby Guelph, so you are welcome for a visit once I get my DD-18 dialed in with my mains & Contrabass.

My mains are the very capable Waveform Mach 17, but lately I run them via my processor cut-off at 60Hz to my sub. For 2-channel, the Waveforms sound much cleaner & open from not having to produce low bass. However, as the Contrabass is LARGE and a passive device, I lack the placement flexibility and electronic controls to dial it in properly with my mains. Also, according to the Ultimate AV sub shootout, the Contrabass is the pant-flapping LFE champ at < 30 Hz tones. It's nice to see the DD-18 win "best real world" honours. I was hoping the Paradigm Servo-15v2 would have made it into the shootout.

- Andy

I will soon be receiving a DD-18 and have a few technical questions:

1. What is the allowable AC Line Voltage (I presume 117VAC nominal) range from low line to high line at full power?

2. Is there a "Soft Start" circuit in event of a power interrupt while the unit is On? Is it a controlled startup or will I have the front/rear door missing?:(


Thanks

[Clubfoot, I am in nearby Guelph, so you are welcome for a visit once I get my DD-18 dialed in with my mains & Contrabass.

Thanks for the invitation Andy, I would love to hear the DD18 in action. One of the intriguing things I like about the DD18 is its extremely low measured distortion.

Looks like I missed the fun on that one, a hot issue.

I am very impressed with how flat you were able to get things.

I played around with my setup a few times, but after moving the mic around I did not see the point in optimizing the single spot in space where the mic was.

I have to move my speakers and cabnets and the three granite slabs, that ride on sorbothane hemispheres, that the amp, premap and CD players sit on. A big job!

I feel that I need to keep my DD-15's close to my main speakers to keep thing phase aligned. I have thought about putting the MG-IIIa's on top of the DD-15s. If that works, I would need to make different bases for the magi's.

My father in law got a DD-15 to replace his ?6 year old? 18" velodyne. I will have to look up the model # & date on the back when I go over to EQ and upgrade the DD-15 software. It has the 2" thick granite looking base.

I am looking for suggestions on how he could sell it. Web sites etc.

I have two DD-15's, one slaved with RS232 to the other. (in stereo mode)

Both are running V 1.5 software.

When I turn off the 'main' DD-15, the other DD-15 does not turn off. So the main unit needs to send code to the second DD-15 to shut down, before it shuts it self down.

When both units are powered off and the main is turned on, the main unit does not turn on the secondary unit. It needs to transmit a turn on code when it turns it self on.

The above turn-on, turn-off actions perhaps could be done even in a stand alone mode if the main does not see that there is a downstream unit. But the secondary unit should not do this, as it knows that it is not a main unit. If there were several DD's hooked up in this fashion, you would not want the second one to add its own traffic to that of the main unit's.

Both units are not in line of site of my seating and remote. The main DD-15 has a remote eye connected. The problems are the same if I hit the main DD-15 directly with the remote.

What do I mean by off? The seconary DD-15's light remains on and it continues to drive its speaker. The RS232 is connected properly and the main DD-15 does control the secondary's volume.

Originally posted by MrHifi

"(<=18Hz)"

My friend, no sub or in fact any speaker I know of puts out anything one can hear or feel below 18 Hz. Sustained LF reproduction in this range will make a human and most apes throw up or become quite ill. The speaker excursion and shear size of the piston area required to produce perceptible tones makes reproduction in this range impractical. My VMPS Super Tower III speakers are 7 ft. tall and use several 15, 12, and 10" active drivers with a 15" mass loaded and adjustable passive driver to achieve an advertised
17 Hz -3dB LF. In fact, in my listening room, which is 62 ft long, 17 ft. wide and 8 ft. high, I can barely perceive anything at 24 Hz when the SPL meter reads 80dB at 400 Hz.

I agree that below around 21-22Hz one stops perceiving it as a certain pitch. However, speaker utterances beneath 18Hz are definitely both heard and felt. At that frequency you hear it as discrete beats and you feel it as vibrations in the floor (I have a raised floor), in your seat, and in your gut, as well as feeling the blasts of air hitting you. Never felt ill, though.

Of course, this is definitely a movie thing. With the single exception of 1812 overture cannons, no music will ever get that low. It's great for movie special effects but more or less irrelevant for music.

The measured response on the DD18 in my room, eq'd as it is to keep the lower frequencies up, is indeed perfectly flat down to 14Hz measured at 100 dB at the listening seat (a typical volume for movie explosions and such). The measurements were done with a test tone disk I burned that goes down to 10Hz (using tones from http://www.snapbug.ws/sinewaves/)and an RS sound level meter appropriately calibrated for measuring low frequencies (see http://www.svsubwoofers.com/faq_rscomp.htm). The Velodyne guys did get this right - when the line is flat - the response is flat. This is with eq, mind. Without the eq I can't reproduce Velodyne's frequency response numbers.

I would hazard that wihtout any eq, it doesn't matter how many drivers you have. Speakers drop off at lower frequencies, and without a boost it's not surprising that you won't get any volume at all <24Hz if you set the volume to a tolerable level at 400Hz. More drivers won't help (unless you cross them over very steeply at very low frequencies). What's required is an 18" kevlar driver, a dedicated amp that can continuously draw 1500 Watts RMS per channel , a multi-band parametric equalizer, and a small enough room that you can get away with only one - i.e., a DD18 in a 1500 cu ft room.

But if your thing is music and not movies, why bother?

A well-designed subwoofer goes easily down to 20Hz and below. Regarding music reproduction, the benefits in soundstaging and ambience of a subwoofer are well known, as in the Thiel PCS (http://www.6moons.com/audioreviews/thiel2/trio.html) review at 6moons.

Val

you guys spend way too much time reading marketing copy. The physics of the situation preclude anything that low and if you wanted to create a speaker that would go that low, it would have to be incredibly large. Equalization is not a solution because in order to get some type of measurable output, the excursion or piston size must be huge. In the '70's an outfit called Norman Laboratories built an equalizer to create more output at frequencies below 50Hz from a Dynaco A25. That speaker was wonderful all by itself and when one added the equalizer which had a gradual gain increase from 100Hz down to 32Hz where it exhibited a +6 dB gain. It really did very little for the low end but make it muddy. Soon went out of business.

Art,

I assume what you are indicating is that the Efficiency of the coupling (impedance mismatch) to free space is very poor, but there is still air pressure changes produced. If the transducer displacement is increased (increased driving power), isn't the volume of air pressure change increased?
Now if we increase the transducer displacement via a power boost (equalizer), why is that a problem assuming there is no distortion of the air pressure changes produced?

Driving any speaker <30 inches to produce enough air movement to enable the human body or the surrounding structures to be impacted by frequencies below 20Hz, requires displacements of 3-4" and throat or horn loading that might require a fireplace opening to be used as the opening of the throat. Fact is, if you listen closely at the low frequencies you wish to hear while driving the spiders well beyond their design levels with high power, what you will hear normally is the swish of paper as the cone fails to couple to the air mass. Try it.

Art,

I'm not sure we can really HEAR the pressurization and rarefaction of the air at such low frequencies anyway. I think we only observe the effects of the action around and upon us.
Many years ago I heard an very large Pipe Organ at the lowest Stop, in a closed structure and I could feel the air change and only hear the banging of a door and the creak of the concrete building.
I have observed the Cone and/or Port noise as you mentioned. That to me is just the distortion factor.

Thank you. that is my point--No matter how much equalization/gain you use you will not hear or feel it at those kind of frequencies. All it does is increase your "distortion factor".

Art - I haven't read all your posts - but are you suggesting that sub EQ is a bad idea? That's absurd. Or are you simply suggesting not to get carried away with dreams of a ruler flat response down to 20Hz?

Originally posted by MrHifi
you will not hear or feel it at those kind of frequencies.

Sure you do. You certainly "feel the air change", as John says. And that's the whole point of going for a flat response down low. It's a great effect that movie sound engineers use to get their point across (like the rocket taking off in Apollo 13).

Other noises that result from moving that much air around the room do of course happen as well, and that's the "distortion", but that's also part of the fun.

Mit07,

The equalizer is a great tool if used in moderation as recommended by the Velodyne reps earlier in this thread. Anyone who has had hands on experience with room equalization will tell you the same thing. Please read some of the previous posts.

Those "down low" frequencies you hear are in the order of 25-100Hz. Introducing very low frequency information below 20Hz is considered foolish because on most equipment all it does is drive amps into distortion, if they are allowed to even respond at these lower frequencies. In the mid to late '80's "DC coupling" became very popular. In theory one could pass DC and have gain applied. Several years ago I cooked 4 drivers of a VMPS STIII when the 300W+ DC amp decided to pass DC. Unless you are trying to arcweld, I would avoid DC coupling.

Speaking of "moving air", my Waveform Mach 17 main speakers each have 2 ports on the front baffle. They can send blasts of air that can make your hair blow 14' away. It's a great extra-sensory effect during explosions, rumblings, tanks, etc !

- Andy

In the '60's, my buddy and I used to build "custom" bass reflex speakers for customers. It was all by word of mouth but it provided dating money with little effort. An interesting and tedious part of the construction involved "tuning" the cabinet so that at the free air resonance point of the speaker you would get no air movement out of the opening. This involved shoving the tube in and out of the circular hole while feeding a sine wave at 40-80Hz into the speaker and blowing smoke accross the face of the opening/port. We achieved some incredible sound using EV LS15 and LS12 speakers. Those willing to spend more would get the SP15 or 12. We used 3/4 " plywood and a horn tweeter and mid range. Cabinets might be 4 ft. high in some cases and always weighed a ton. But oh the sound.

With regard to your two ports on the Mach 17's. I own a pair of Electrovoice Sentry III speakers with two ports on the front of the cabinet. The ports are different sizes. When one used the SES equalizer to extend the low end to 28 Hz -3db, you covered up a port with a supplied piece of wood. When you wanted greate efficiency and were willing to sacrifice the extra octave provided by the equalizer, you took the wood off and attached it in a storage area on the speaker. The EV Sentry III's are a bass reflex design and came out within a year after Thiel published his now famous equations. EV adhered meticulously to those equations producing 2 speakers that I feel were highly underrated. The Sentry III and IV. IV's were used estensively in Disneyland and later Disneyworld. It used to make me proud to look up and see my 25"x10" midrange sectoral horn floating above me while singing "It's a Small World".

Art,

I seem to recall that back in the late 50's, during my "HiFi" days, I think there was a manufacture (EV ??) using a 24" Sub Driver.
Did you ever work with one of those monsters?

Hi,
The most famous 24" was the Hartley. I think that was the name. EV actually had a 30", made of styrofoam (or a similar material) as I recall, though it was not a great performer.
Curt

"The equalizer is a great tool if used in moderation "

I do believe Art is correct in that statement. It would be ideal if we could reduce the Room Standing Waves/Modes to a minimum through Acoustic Treatment and then settle to the Equalizer as last resort.
Unfortunately I don't think my wife would stand still for the look of the area.
I am picking up the DD-18 today and when all is adjusted, as Dave Penny mentioned..........All you have to do is just open or close one door/window and the Equalization will change.
BUT I will try the best I can:)

Curt,

Your correct the EV was a 30" and was not to great for clarity. Servo Control anyone?

The 30" EV speaker was used in the Patricians. It was paper with a paper all the way to the basket frame. Although it was not the lightest speaker available, it moved a lot of air. My friend and I built a 3 way system in corporating a 30" and a 15"TRX speaker. It required such a large box that the customer allowed us to seal a closet and set it up as an infinite baffle. It moved a lot of air but frankly didn't sound all that great. Although EV offered an easy solution for building 1,2 or 3 way systems, they never sounded as good to me as the Jensen free standing imperial Horn with JBL LL-15 woofers. This speaker incorporated a rear loaded horn with the woofer facing outward as opposed to the Klipschorn design where the woofer acted as the source deep in the throat of a quazi/cutoff 16 ft horn. I never liked the klipschorns because they had very little real ouput below 50Hz unless you positioned them absolutely correctly in a wide room with flat long walls on both sides of the corner. The Free Standing imperial Horn looked more like the Altec Lansing A7-500, my personal speaker choice for almost 10 years in the late '60's through the mid '70's. I give credt to those speakers for my excellent recordings on R to R. They reproduced every bit of crap on the disc or hum if it was present. i went through 2 Dynaco 400's and 3 Crown DC300A's and even the worst of the lot a Macintosh solid state amp which was so noisy i could not stand to have it in the same room as the speakers.

Hello,

My name is Aureliano and I live in São Paulo, Brazil. Have just enrolled and at once I thank the attention.

I possess a DD-12 and I am with some difficulties. It happens that, in the way EQ, don't get to visualize the curve of the subwoofer separately and of the mains (as it recommends the manual). That happens because the entrance CD of my processor (Rotel RSP-1066) makes bypass of the sign emitted by the subwoofer and then the mains (Dynaudio 52SE) play starting from 45 HZ, hindering the adjustments.

I would like to continue using the crossover of the processor, but for that I would need to emit the sign of the sub through DVD. Right? Can anybody help myself ? Does that sign exist in a file that the velodyne could supply myself ?

Excuse for bad English.

Thank you,
Aureliano

AConte,

The signal from the DD goes through an unused input on your amplifier. You have the amp, main speakers and DD play the sweep signal from the DD. The microphone then listens to this and feeds that to the DD. You then see the DD video output on a video monitor. You then adjust the EQ on the DD.

After you adjust the EQ in the DD, you select the music source on the processor that you wish to listen too. The DD is then not in the signal path to the amplifier.

You can use the 45Hz low pass from the processor, or a full signal to the DD. So you use the lowpass filter of the DD or the processor, but not both. To turn off the low pass filter of the DD, set it to 199Hz. Using both low pass filters can sometimes not work well.

Feeding the speaker level to the DD,and using its internal low pass filter, is also a good option.

Which model is better...?

CHT8
DLS3500
VX10
VRP1000

Thanks!

Got the Electronics and Driver of our FRS-15 back from Velodyne repair a few weeks ago. Last night when I turned on the Sub, I got that constant popping sound again. After unplugging the Sub, disconnecting the input signal, and turning the Sub on and off a few times, the sub doesn't pop anymore, it just sits there with the driver moving in and out.

When Velodyne repair found no problem with the Electronics, I sent them the Driver. Excessive Hunting caused by an aged accelerometer was found, and the accelerometer was replaced.

I'm planning on calling Pete at Velodyne on Monday. Anyone out there experience a malfunction like mine? If so, what did the problem turn out to be?

Folks at Velodyne, what do you think? Are you familiar with problems of this nature? If so, would you please share your experience with your service department.

In fairness to the Velodyne service department, the problem started out being intermittent.

Thanks.

Bruce

As per your previous suggestion a few months ago, I've run outputs from the DD 15 to my HGS 15.

The HGS 15 has the crossover disabled but it seldom triggers automatically unless the preamp output volume is very high whereas the DD15 switches on automatically at reasonable levels.

Is there any way of rectifying this anomaly?

Thanks

Darryl

Originally posted by darrylp
Bruce

As per your previous suggestion a few months ago, I've run outputs from the DD 15 to my HGS 15.

The HGS 15 has the crossover disabled but it seldom triggers automatically unless the preamp output volume is very high whereas the DD15 switches on automatically at reasonable levels.

Is there any way of rectifying this anomaly?

Thanks

Darryl

Unfortunately the auto-on sensitivites between the two units are different. We purposely were able to use less signal to turn the DD back on since it is digital and therefore more precise.

What I would recommend is defeating the auto on for the HGS. At idle, it uses very, very little power. Let the DD auto off and on and leave it at that . Wish I had a better answer for you but this is at least one solution.

Hope this helps,
Bruce

Thanks very much Bruce

I assume it won't damage the amplifier if it's on 24/7?

Another question please:

As I've Def Techs 7000sc with their built in subs and all others speakers (except the center) being run as large, do I feed and process as a PLllx the signal from the DD15 when I'm equalizing the bass response utilizing the DD15?

Regards

Darryl

When i run the test tone on the DD15 on what seems like the lower frequencies, there seems to be a rattling and chuffing sound coming from my sub. Once it hits a higher frequency, maybe 40-50hz it seems to tighten up and sound ok. So my guess is at higher excursions is where i am hearing this problem. Anyone hear this or know what might cause it?


EDIT: Actually it doesnt seem like the noise is frequency dependent. When the tone starts there is this wobbling of the driver while the tone is created. Im ont sure what the noise is as the unit seems to be producing bass. ITs as if the driver inside is scraping against something.


Also, any of the servo settings sound the same.

John

A short while ago i tried to explain to folks in this forum what happens to drivers at frequencies below 17Hz. you describe it perfectly. It is caused by the fact that at these frequencies, there is very little coupling" of the piston, the cone, to the air. You might hear this effect and you might not depending on the characteristics of the box or minutedifferences in crossover component values or a myriad of other things. My 18" does it below 17Hz.. Do not worry about it.

Originally posted by MrHifi
A short while ago i tried to explain to folks in this forum what happens to drivers at frequencies below 17Hz. you describe it perfectly. It is caused by the fact that at these frequencies, there is very little coupling" of the piston, the cone, to the air. You might hear this effect and you might not depending on the characteristics of the box or minutedifferences in crossover component values or a myriad of other things. My 18" does it below 17Hz.. Do not worry about it.

I can hear this scraping sound from 8ft at certain volumes (though based on your explanation volume probably shouldnt matter?), does that seem normal based on your experience? I must say, it doesnt sound 'right' to me but since the bass seems to be coming out normally, your explanation does make sense.

I almost wish the driver was busted because i could hear it during LOTR:ROTK during some scenes before and it was a little distracting.

Are there any tests you could recommend that i could run that would confirm proper subwoofer operation?

Thanks for your help.

John

John.............

I have a DD-18 and as Art mentioned correctly there is poor "coupling" to the surrounding air. I do hear the typical, what I call "Speaker Cone Noise" until about 20Hz (may be at a higher frequency for the 15"). It is NOT any scraping or rubbing noise.

I have found a cabinet resonance noise at about 110Hz (and other frequencies) and am waiting for a response from Velodyne Tech. Support. It has been about a week with no word yet. :(

John,
Just pick up the phone & call them.
They have historically been readily available & very helpful.
The only frustration I've had with them is getting a direct answer regarding discrete codes for the DD18 remote....
I have not noticed this in mine....yet.
Could it be because my room is 42' deep to rear wall?....maybe it would occur at a lower frequency?

Originally posted by cajunlab
John,
Just pick up the phone & call them.
They have historically been readily available & very helpful.
The only frustration I've had with them is getting a direct answer regarding discrete codes for the DD18 remote....
I have not noticed this in mine....yet.
Could it be because my room is 42' deep to rear wall?....maybe it would occur at a lower frequency?

Yes i have spoken to them today regarding this and a resolution is underway. THey seem to think there is somethign wrong with the driver as well so its on its way. They were very helpful with this.

John

For discrete codes see link;

http://www.remotecentral.com/cgi-bin/files/rcfiles.cgi?area=pronto&db=devices&br=velodyne&dv=subwoofer&fc=

Curt

Originally posted by curt c
For discrete codes see link;

http://www.remotecentral.com/cgi-bin/files/rcfiles.cgi?area=pronto&db=devices&br=velodyne&dv=subwoofer&fc=

Curt

Great news curt!

The author states that software 1.6 is required for these to work. When will this be made available?

John

It seems I got the horse ahead of the cart.
1.6 will be up for download in less than two weeks.
Sorry bout that.
Curt

Just got my DD-18 yesterday !
I have never owned a Velodyne product up until now. It is a very impressive visual piece, and the fit & finnish of my gloss black unit are top-notch ! Nice packaging, complete accessories, etc ... just what one would expect out of a top-rated product/company.

Setup was extremely quick, and the user interface is very inituitive. My complements to the Velo engineers for keeping it simple, yet highly functional. Within 1/2 hour and basic fooling around, I had great sound when mating the DD-18 to my Waveform Mach 17 mains, crossed over at 60 Hz. There will surely be hours/days/weeks/months of fine-tuning, customizing, and of course happy listening. This is an exciting product no doubt !

Software FYI ...
There is only one EQ curve that you can define, and this is a global EQ curve that is then used by each of the 6 presets. Each preset will use that global EQ curve along with each preset's unique filter crossover frequency, slopes, relative volume, phase, subsonic filter, servo-feedback, and 1 extra EQ/Contour setting.

I had thought/hoped that each preset could have its own unique EQ curve, rather than rely on the global EQ curve ? Now one may ask why one would want/need that ability. There are scenarios that would/could benefit from it ... such as running multiple subs ( or not ), running the mains full-range ( or not ), etc. This is not really a big deal for me, but any thoughts on this ?

- Andy

Hi Andy,
You're not the only one. Look for a future software update to provide separate EQ's. And I can't thank you enough for the kind words. You made my day, and weekend too.
Curt

Curt, I am fortunate to start out with your top-dog ! :) ... well, 2nd top-dog after the 1812.

I look forward to a software update and continued discussion on this "revolutionary" product. Sure we can do it all separately with a few extra external parts, but this all-in-one tidy solution A) delivers B) shows great leadership & anticipation of future trends & consumers' desires.
OK, I'm done buttering you guys up :)

- Andy

Curt, I spent some time over the weekend integrating all the new commands into my pronto remote and just wanted to commend Velodyne for really going above and beyond on this. The sheer number and flexibiility of the discreets is really amazing. Offering these features is one thing and being able to easily integrate them into an automated system is something else and velodyne now, imo, has the most flexible, powerful, sub system out there. Thanks again for delivering on this.

John

" . . .spent some time over the weekend integrating all the new commands into my pronto remote and just wanted to commend Velodyne for really going above and beyond on this. The sheer number and flexibility of the discreets is really amazing. . . "

Where do I find these "new commands"? I want to improve the programing of my Home Theater Master MX-3000 to control my dual DD-15's.

I did not find any new software updates on the Velodyne software update page except Update v1.5 released way back in May.

How do I get the "new commands"?

Thanks,

Chris Cargen

and approximately when is the BIG UPDATE scheduled to be released?

Hi All,
Here's the link for the 1.6 software update;
http://www.velodyne.com/velodyne/support/softwareupdates.aspx?sid=390g601j
Curt

Curt,

Nice update, but I was under the impression that there was something BIGGER planned. Was I incorrect?

thanks

Randy,
The "Big One" should be first quarter of next year.
Curt

now THAT's what I be talkin' bout.

thanks, Curt.

Ran

I have a 2 sub set up. My mains can go really low. My question is if is better to set the speakers as large in my receiver, connect my receiver to the speaker level inputs of one of my subs, set the high-pass crossover to 80hz in the sub, then connect my mains to the speaker outs in the sub, and finaly connect my other sub to the sub out of the receiver. (this is to get the most of my mains, I feel that i'm loosing some of their performance by setting them as small in my receiver. This way the mains would be playing down to 80hz.)

Or is just better to use a Y cable and connect both subs to the sub out of my receiver.

Thanks.

Use your receiver's sub out. The speaker level path is infinitely noisier. Depending on how low your mains go, I'd use large if possible.

Originally posted by curt c
I agree with Art, unless your speaker's woofers are 61/2" or 8" in which case I would call them "small" regardless of what the manufacturer claims the response to be. If you call them "large" then adjust the low frequency on the Velodynes to integrate with the speakers. If you wish more info. or your issue hasn't been addressed properly, call me direct at; (480) 595-7141 during the week.
Thanks,
Curt

Thanks Curt and Art, I really appreciated.

To all the gang at Velodyne, thanks a million for the V1.6 software update. The final piece of the puzzle for fully integrating my Home Theater with the Pronto 7000 was getting the discrete codes for the dual Velodyne DD-15 setup. I now finally have a setup and menus that work the first time, every time. Again, thanks a million, you've made at least one customer very happy.

Originally posted by rwright902
To all the gang at Velodyne, thanks a million for the V1.6 software update. The final piece of the puzzle for fully integrating my Home Theater with the Pronto 7000 was getting the discrete codes for the dual Velodyne DD-15 setup. I now finally have a setup and menus that work the first time, every time. Again, thanks a million, you've made at least one customer very happy.

It took way longer than it should have to get those out, glad they're working for you!

Bruce

Curt,

What is involved in the "big update"? Fully auto EQ I hope!

-Brian

Auto EQ and more!
Curt

Originally posted by curt c
Auto EQ and more!
Curt


...and more BIG smiles!!! :)

I had "auto eq" on a 12 band equalizer years ago. Results sounded terrible because after the algorithm reiterates trying to satisfy the variable limits until it is unable to and defaults to a time limit when it accepts whatever was possible. If yo achieve a working unit that does not go crazy oscillating between set points, my hat will be off to you curt. At that point you may wish to market the automated equalizer alone.

Yes, it is difficult to EQ "somewhat flat" manually as it is.
But Auto-EQ is expected in any of today's elite products, even though it may not yield the most optimum sonic results.

I look forward to visiting the Velo gang at CES.
Do you plan to show any of the new software in prototype form ?

- Andy

MrHifi,
Good point about programming loops without graceful exit strategies.
I hope they can deliver AutoEQ "somewhat flat".

If Velodyne can deliver an AutoEQ upgrade that results in "somewhat flat" I will be truly impressed. If more processing power is needed maybe they can offload the processing & interface with a laptop thru the serial cable.
They did deliver the discrete codes.
C'mon Bruce Hall, we're pulling for you in your attempt!

Cajunlab,

Unfortunately, the problem is not prcessing power, it's physics. The mic reponds to room resonances and cancellations Your brain does not perceive those. When the algorythm tries to correct for the resononces and cancelletions by boosting and cutting at discrete frequency intervals with filters that have a Q (frequency width about a defined center for our purposes here) that is wider than necessary-must be that way-, you wind up with awful sound. Remember computers are no smarter than we are. They certainly can not out accomplish what a real person can do in this case. Tht is why IMHOm I would never use the built in automated room equalizers that are so prevalent today. If you have ever watched a qualified sound engineer try to decide on the best Eq at a venue, you would understand what I'm trying to say. I've never seen anyone rely on an automated process. This is an art . I hope the folks at Velodyne are sucessful. But I believe the "exit strategy" as you put it, is critical to their success. Good point.

How to hook up CH10

I will try to be brief. I have a Kenwood vr 509 with a single RCA preamp out for the sub (no L & R) I just got a CH 10. I am mating the CH10 with Bose Acoustimass 10's

What is my best setup option for this system?

Hi,
I sent you a PM.
Curt

Hi Curt

What's the best way of receiving an alert when upgrade software is released by Velodyne?

Thanks

Darryl

Hi,
We will keep you posted here. You can also check our website.
www.velodyne.com

Thanks very much.

Darryl

Curt,

In your experience with integrating subwoofers in home theaters, have you found it better/easier to set all speakers to small when using a single sub? With an ear towards the smoothest inroom response!

Hi,
Yes, usually. It simplifies things. Most speakers sold today use one or more 61/2" woofers, which are really midrange speakers. Also when multiple drivers are playing or attempting to play the same low frequencies some complex and often bad things can happen.
If one has (really) large speakers and they can experiment with placement, then augmenting with the subs low frequency set at 40-50hz can provide good results. In this case you would set the speakers to large.
In one of my systems I have fairly large towers and the system sounds best with the towers crossed over at 80hz.
You can always try both methods and see which sounds better.
Curt

Curt's point is well taken. I use VMPS STIII's which have several 15, 12 and 10 LF drivers. I cross over at the processor's LFE channel max of 120Hz. I do not use the speaker's built in lowpass filter. I only use the sub for 5.1 material because the speakers sound perfect by themselves. I bought the 18" sub to use for "explosions" and that is how I use it.

Thank you both for your responses. It has been my experience in my 13.5X23.5X8 that in 5.1 movies the system sounds best with small +sub. But, I still tend to prefer large +/- sub for stereo and high resolution audio play back. I keep thinking it's just my old habits/preferences, but the "fuller" sound in large sounds more pleasing for music, it just may not be that accurate. From my own measurements small + sub results in a flatter response in the base region and it also cleans up those nasty room modes as well. I'm patiently waiting to purchase one or two of your DD subs for my basement HT.

What is everyone's thoughts on subwoofer isolator boards?

I noticed on some of the cool install pics ont he velodyne website they are used and just read an article which mentioned them.

If we all agree they are a good idea, anyone have any suggestions on which ones to buy?

My room is a basement floor (concrete) with industrial-style theater carpet and i think a 1" foam pad underneath.

Thanks!

John

Curt or Anyone :-)



Thinking about buying a DECO system; I know its not a current product. But I was having some issues the 4ohm drivers, my receiver is not a fancy unit. I have a Panasonic SA-XR50 digital unit, 6x100. I know its not an HK or Denon, but it does produce clean and powerful output.

Any tests or complaints (for that mater any positives)


my room is a converted bedroom to HT room - only 12x17. I had been using a set of Athena AS-F2's for my front (no need for a sub with the quad 8's) and even my little panny could make them move :-) But one of them was damaged by a non audio disaster (long and most likely boring story). And the wife of the house would like me to get a BOSE AM6 but well I can't do that :-) so I saw the DECO on sale at 1call and thought I'd ask before buying them!


Thank you in advance,

John

I posted this same info on the uk forum in case anyone sees it there as well...

I'm having some trouble with my DD15 and i cant figure what could be causing it.

About 3 weeks ago i was playing a concert DVD (U2 live from boston, 5.1 track). When i heard this really loud crackle come from the sub. (The tracks that seem to be most problematic are #1 'elevation' and 'where the streets have no name')My volume was on 25.

I changed the power source from an outlet near the sub to running the power cord to a monster power 3600 through a heavy duty extension cord.

Played the Disc again after a little while *crackle*. It doesnt seem to happen at exactly the same place either. After the second crackle i could now hear a scraping and fluttering of the driver during high excrusions (low frequency) in the EQ setup screen.

I sent the sub in and velodyne replaced the amlifier and re-calibrated it.

I received the unit back and went to the eq setup screen and the scraping and fluttering was gone. Sounded good.

I placed it back and found that if i closed a door to a little room adjacent to the home theater, i had a bit more bass. SO now i was able to lower the volume to 19 for the same effect.

Put on the U2 DVD and *crackle*. NO other DVD does this to the sub so far and i have a 10" rbh sub that plays the whole dvd with no issues.

I can hear the driver begin to flutter a little now even tho its not scraping yet, i think ive knocked it out of whack again.

Does anyone have any idea on what might be happening here?

My completely uneducated guess is that since this DVD has sustained bass for extended periods of time as opposed to movie soundtracks, there is some sort of charge building up in the electronics or something.

Any help is appreciated.

John

Sounds to me like you are hitting a resonance point and the servo is unable to control the resonance. However, for what I just speculated to damage the driver, there should have been some pretty loud booms before the damage occurred.

The driver was never damaged according to velodyne, it was only the electronics.

Whats a resonance point?

John

[QUOTE]Originally posted by johnner1999
[B]Curt or Anyone :-
"Thinking about buying a DECO system; I know its not a current product. But I was having some issues the 4ohm drivers, my receiver is not a fancy unit."


Hi,
I don't think the 4ohm rating will be an issue. They have been used successfully with many entry level receivers.
The DECO system is the best small system I have heard and the woofer is "state of the art". You won't be disappointed. I own a set.
Curt

Originally posted by MrHifi
Sounds to me like you are hitting a resonance point and the servo is unable to control the resonance. However, for what I just speculated to damage the driver, there should have been some pretty loud booms before the damage occurred.

Thanks for the input but i was more looking for ideas on what i may be doing upstream that would cause a problem with any sub, and not just this one.

The guys over at Velodyne are always real helpful and responsive so i know if its a sub-related problem theyll get to the bottom of it and make it right.

I've been in contact with them on this and the service is and has been first rate.

I mostly wanted input on whether or not i was doing something wrong that would break the sub.

Thanks again for the suggestions.

John

Originally posted by curt c
[QUOTE]Originally posted by johnner1999
[B]Curt or Anyone :-
"Thinking about buying a DECO system; I know its not a current product. But I was having some issues the 4ohm drivers, my receiver is not a fancy unit."


Hi,
I don't think the 4ohm rating will be an issue. They have been used successfully with many entry level receivers.
The DECO system is the best small system I have heard and the woofer is "state of the art". You won't be disappointed. I own a set.
Curt


cool thanks -- I know you have a "slight" bias but do the sats produce good mid-bass for HT and TV use? and how is the dialog? for a reference point the room is a converted bedroom about 12*17 and I have Mirage AVS-100/200 in use for sats currently


Thank you again

John

John,
The DECO satellites are meant to be used with the DECO subwoofer at all times. The satellites go down to 100-110hz pretty well and should be crossed over at somewhere between 80-120hz depending on what your receiver offers. In speaker setup designate your speakers as "small". That will activate the crossover in you receiver. Dialog is excellent. These were not meant to be cheap speakers.
Curt

Curt,

Thanks for all the informative posts. I need some assistance in selecting the right DD unit. The room is approximately 27 x 16 x 7 or approximately 3,000 cubic feet. This room also is open to a second room of adding approximately 1,260 cubit feet. I have a DD-10 on demo but do not believe its the right sub (my dealer felt that it would work well in my space). At any point would a DD-12 of DD-15 be a better choice?

Hi,
This size room calls for the DD-15 or DD-18. The DD-12 would be working too hard.
Curt

Curt,

Thanks for the input. I was leaning to the DD-15 and your post just confirmed what I already knew.

Happy Holidays

I am have read through this thread, but am a bit confused on how to set up a dd10 in my system. My room measures about 1,700 cu. ft & I want to primarily enhance 2 channel listening.

I have a Krell HTS 7.1 (analog bypass for main L/R only) with ATC 20-2 active speakers. Bass seems to roll-off around 100hz with minimal sound at 40 hz. I am using XLR connections from my Krell to the ATCs. I would like to use the main L/R rca to go to the DD10.

Some questions:
I assume I would keep the speaker at Large since I am trying to send the signal to both the main speakers and sub?
Any recommendations on where to set the crossover on the sub given the roll-off?
A previous response indicated when setting up the cable from the DD would go into an unsued input into the amp? (is this correct- I have active speakers with no inputs) (would it be preamp & do you need to set it up as a device?)...can someone explain this part of the setup?

If I have the option, I would laso like the dd10 to replace my older Velodyne F1200x for HT duties. I assume there are enough inputs to accomodate this? Does the setup process accomodate dual uses? While I would like to do both, my emphasis is on 2 channel listening.

Any suggestions would be appreciated.

macct:

I also have a HTS 7.1 and a DD-15 sub. I ran the XLR sub-out from the HTS 7.1 to the DD-15 XLR input. When calibrating, I input the DD-15 RCA audio into AUX-2 (default is S6 inputs on the HTS) and ran the video to my projector. I set the front speakers for Limited and the AUX-2 channel for Stereo mode (Preamp mode bypasses the digital processing and doesn't cross over the fronts and sub) during calibration. I was then able to follow the Velodyne owners manual for calibration.

Remember in Preamp mode (analog bypass) there is no digital processing done so the speaker configuration setting (Limited vs. Full Range) and crossover is not being used. A full frequency signal is sent to your fronts and nothing to the sub. Configure your music channel for the stereo mode, limited fronts, and cross over at 100Hz and you should be fine.


MT

Thank you for the clarification. It has explained part of it. I do want to set the dd10, however, with the preamp mode so there won't be any additional processing. I find the preamp mode has a cleaner sound than using the stereo mode (tried w/ the F1200).

Any idea if the set up menu will be able to accomodate using the rcas in as well as LFE in?

thank you again

macct:

The guys from Krell told me that the Preamp mode bypasses all of the digital processing so, as I understand it, you will get no signal from the sub/LFE outputs on the Krell in this mode.

When you assign the input a digital mode like stereo, Dolby, or even 7.1 all of the processing specified by your set-up configuration is applied. I only use my DD-15 as an LFE. But if you want the DD-10 to integrate with your fronts you have two options. The first option is the one I described earlier, where you use the Stereo mode, crossover at 100Hz and set the fronts to Limited (this mode has the advantage that your sub will also act as an LFE for movies). The other option (if you want to bypass the digital processing) is to send the front L/R line inputs from the Krell to the sub and use the subs line outputs (I think they are called THRU on the Velodyne) to your speakers then configure the sub to crossover at 100Hz. Now you can use the Preamp mode for music and set your fronts to Full Range for all the digital modes.

You can decide if you would like an additional sub for LFE based on the sound you get from option 2. A dedicated LFE channel for movies does add quite a bit more impact and can be very enjoyable if your wallet will allow.

Good Luck

MT

Yes, I realize the preamp mode does not have LFE. Ideally, I am try to get the sub to do 2 things....1 for music & the other for HT.

For music I want to use the preamp mode. My speakers require XLR inputs & the typical installation won't work. I have spoken with Krell and they indicate I can run the XLR and rca main L& R at the same time (one to the speakers & one to the sub), effectively tricking the preamp so I can have the sub into the equation. The only part I am not clear on if it matters if I need to set the speakers for small (w/ crossover) or large. From what you are saying there is no crossover in preamp mode, so I can set them to small. correct? Is there any reason this setup won't work?

For HT, I would use the LFE connection (for music listening the preamp will not be sending a signal). For HT use, is there any issue passing main L&R bass plus LFE? When setting the unit up, should I be setting it for HT or music (no LFE)? or can I have a second set of parameters?

Sorry for all the questions, I just want to make sure a dd sub would be a good fit for my system.

Macct:

No problem. I too am a survivor of Krell documentation. A couple points: In the Preamp mode I don't believe there is any signal from the Krell Sub output so sending the front L/R to both the sub and the speakers will cover that base. In analog mode (Preamp) on the Krell there is no crossover function, full range signal will go to both your speakers and sub (since you are feeding both with front L/R outputs) so you'll have to roll off the sub's frequency through the Velodyne's set-up menu. Also remember the speaker configuration (Limited vs. Full Range) has no effect in the analog, Preamp, mode.

I don't believe you can send both the sub and front L/R outputs from the Krell to the sub so you can use it as both an LFE for movies and as a sub/sat speaker configuration for your fronts without some degradation. It should work for music but the bass may a bit muddled on movies when the logic is simultaneously sending front L/R and sub signals to the same speaker. Give it a try and see what you think. If you don't like it I'm afraid you'll either have to go back to my configuration 1 (Stereo mode) or add an additional sub.

MT

Originally posted by curt c
John,
The DECO satellites are meant to be used with the DECO subwoofer at all times. The satellites go down to 100-110hz pretty well and should be crossed over at somewhere between 80-120hz depending on what your receiver offers. In speaker setup designate your speakers as "small". That will activate the crossover in you receiver. Dialog is excellent. These were not meant to be cheap speakers.
Curt


Curt I went ahead an bought a Deco set today (great price at $575 new from an online dealer whom I think is a Velodyne dealer?, didn't this sell for close to $1100 when it first came out)

my biggest concerns are still my digital Panasonic shutting down you know 4 ohm issue? And rich full sound from small speakers (wife wanted Bose AM10's). The spec sheet states that the main speakers have 4" drivers (I guess I'm getting since that seems small?) with 3.5" cone what does that mean?

again thank you and I hope they were the right ones ;-)


john

Connected correctly, with the subwoofer you will get rich full sound. I doubt there will be a problem with the 4ohm issue. Yes the system was meant to sell at $1199. A driver (4" in this case), always has a cone size (piston) a bit smaller, 3.5" in this case. It depends on how you measure it.
Hope this helps and enjoy.
Curt

Originally posted by curt c
Connected correctly, with the subwoofer you will get rich full sound. I doubt there will be a problem with the 4ohm issue. Yes the system was meant to sell at $1199. A driver (4" in this case), always has a cone size (piston) a bit smaller, 3.5" in this case. It depends on how you measure it.
Hope this helps and enjoy.
Curt



again thank you -- for comparison sake how does the Deco stand up next to a BOSE AM10 or AM15 setup?

Honestly there's no comparison. You'll see. The Bose system is small and cute. The DECO system is a serious high-tech three way speaker system.
Curt

Originally posted by curt c
Honestly there's no comparison. You'll see. The Bose system is small and cute. The DECO system is a serious high-tech three way speaker system.
Curt

really? is that because you work for Velodyne?

I guess its due to me not being able to "hear" the Deco's 1st...


confused in HT land :-)

John

That's a lousy response to Curt's answer. You asked the question. Go play somewhere else.

agreed.

Originally posted by MrHifi
That's a lousy response to Curt's answer. You asked the question. Go play somewhere else.


this is just one example of how some things sound the wrong way to everyone except the writer...

I honestly wasn't putting Curt down (I've only been on this section of AVS for a day or two but do respect the person!)

in my shortness I was only seeing if more information was available.


Curt I hope I didn't offend you and if I did I am sorry!


<john leaves the area...>

No problem, no offense taken. I think you'll come to realize what a great bargain the DECO's are. We'll be off to CES this week.
Happy New Year to All!
Curt

I purchased the Velodyne CHT10 in early November 2004. I've been quite impressed with the quality of the sub and the amount of bass that it generates. Unfortunately I've had the sub cut out on me twice since owning it. In both cases it seems the sub did not cut out while being put under strain but rather sometime afterwards. i.e. I put a dvd in and turn the volume up and no bass.. almost as if it decided to cut off after some hard work the night before.

It happened the 2nd time just last night. Flipping the power switch off and on resets it no problem. After I reset it I tried a dvd at volumes above what I would normally listen to and it ran like a champ. No shut off.

It's only happened twice so it's not a huge concern but I wonder if I might have a problem with the amp. Is a sub cutting out a rare occurrence? Also does the sub normally cut out when it hits a single powerful signal or does it take a couple of hours or heavy use to heat it up and eventually cut it off?

Concerned.
Sid.

If you are using auto turn on, then you are probably not triggering the amp to turn on with a high enough level. My auto on has gone buggy so I just leave the amp on all the time. Try that and see if it continues to operate.

Originally posted by curt c
No problem, no offense taken. I think you'll come to realize what a great bargain the DECO's are. We'll be off to CES this week.
Happy New Year to All!
Curt



I hope it is OK for me to post again here (if not Mods please remove)


Update on my Deco's -- as Curt assured me they sound GREAT (a little too weak on some throaty type male voices but not bad for a SAT system!)

Only down side is my digital Panny shuts down while watching a movie, normally about 20-30 minutes pending volume level. :-(


on a differnt note the Sub is very Velodyne (a good thing) very solid and no "boom" at all which I think is GREAT!!! It is also sealed which I actually like but how can it handle/make 600w rms / 1200 peak? most high output units I've seen are ported to help with the power.


I hope I can figure something out :-( cause I love this little set!


Thanks again....

John

DD series subwoofer installation questions

Hi,

I have questions regarding installation setup 2c and 2d in the manual.

2c INPUT, LEFT and RIGHT
Make a connection between these inputs and the stereo outputs of your receiver or processor.
Does it mean that the receiver requires to have a pre-amp out so that part of the signal goes to the subwoofer? The power amp section of the receiver drives the main speakers.
Can the subwoofer be placed between CD player and the amplifer? Connecting the CD player to INPUT of the subwoofer. Then connect the OUTPUT of the subwoofer to the amplifer?

2d SPEAKER-LEVEL INPUT
I cannot quite get how SPEAKER-LEVEL INPUT is done. It says: Make a connection between these inputs and the letf and right speaker connections on your receiver or processor.
If I make that connection, where should the main speakers be connected to? to the subwoofer? (but I don't see any terminals out to speakers) to the amplifer? (but the output has already been taken up by the subwoofer)

Thanks

" It is also sealed which I actually like but how can it handle/make 600w rms / 1200 peak? most high output units I've seen are ported to help with the power. "


John,
A small sealed sub (like your DECO) requires a lot of power to generate some credible spl's. The small 8" driver has to be pushed quite a ways (long throw) and the small sealed enclosure is acting like a spring, resisting the movement. Bass reflex designs (ported, slotted, or whatever) require less power since they are more efficient. They are utilizing the front and rear wave of the driver. Their design does not help absorb more power, they need less power. Remember a 3db increase in volume requires twice as much power, so you can run out of power rapidly as the volume goes up. Our robust drivers are up to the power required.
Hope this helps.
Curt

Curt - right on the money! I never thought of it that way, but yes it really does put out a nice clean low solid bass note. many of the other "boxes" I looked at were too loose/boomy IMHO (Inifinity the most)

I hope I can figure out my problem, as I don't want to return these :-)


again thanks for your help and guidance!

JOhn




Originally posted by curt c
" It is also sealed which I actually like but how can it handle/make 600w rms / 1200 peak? most high output units I've seen are ported to help with the power. "


John,
A small sealed sub (like your DECO) requires a lot of power to generate some credible spl's. The small 8" driver has to be pushed quite a ways (long throw) and the small sealed enclosure is acting like a spring, resisting the movement. Bass reflex designs (ported, slotted, or whatever) require less power since they are more efficient. They are utilizing the front and rear wave of the driver. Their design does not help absorb more power, they need less power. Remember a 3db increase in volume requires twice as much power, so you can run out of power rapidly as the volume goes up. Our robust drivers are up to the power required.
Hope this helps.
Curt

I just purchased the Deco 5.1 speaker system. Now I need to get a pair of floor stands for my front speakers and wall mounts for my two rear surround sound speakers. I see that Velodyne recommends Sanus stands and OmniMount mounts. Is there a particular model number for each that would work best for the stands and the mounts respectively?

Thanks in advance for any advice.

just want to give props to this subwoofer platform... put it beneath my DD-12 last night and watched The Village which had some deep bass notes. i immediately noticed that the bass was tighter and more defined. moreover, rattles on the walls, ceilings, etc. were significantly diminished if not eliminated. it's definitely a keeper.
fyi, my theater room is an enclosed 12' x 16' room with carpeting.
i hope they make a smaller and cheaper one for tower speakers. i'm currently using Auralex's MoPADs under my Infinity Alpha 50s which is on hardwood floors in the living room.

What you have done is decouple the subs from the floor thus decreasing their effective output at the lowest frequencies by 6-10dB. In technical terms--Floor mounted/designed speakers are made to operate in quarter wave space. Shelf or wall mounted speakers are sesigned to operate in half wave space. The low end is tuned appropriately. I believe most Velodyne subs are designed to operate in quarter wave space. Curt---correct me if I am wrong please.

Art's point is well taken. When you remove the deep bass many think they're hearing cleaner, tighter bass. Not so, just bass that doesn't go as deep. The deep (usually inaudible) bass was causing the rattles. So yes you eliminated some of the deep bass.
Curt

I dunno, but something sounds a little fishy to me. Was the sub actually on carpet before being placed on the SubDude? It seems that the issue could have been more of a sub/floor vibrational problem than a low bass one. Surely, elevating a sub an inch or two doesn't mean the sub isn't operating into a quarter wave space if it's still in the corner.
???

Ran

Wrong!!!!!!!!!! My 7 ft high VMPS STIII's are designed to operate on the floor with the passive radiator firing downward into a 1" piece of particle board. The opening through which the radiated bass from the passive sub must becoupled tightly in order to get the -3dB down point to 17Hz. I bought a second pair from an older gentleman who had one fall over in his room and crush a nightstand. He installed a 3'x3' piece of 2" plywood under the speakers to give them more stability than that offered by their 18" square normal footprint. The result was a speaker that sounded terrible. No low end and some indescribable cancellations that in the end made me give them away to a friend who had the strength to lug the 400 lb+ monsters around. I kept the two I purchased directly from VMPS. Dick Chaney himself tuned them and came to my home for final tuning and setup. BTW, Chaney replaced the four 4" midrange drivers in each speaker with carbon fiber drivers he had just purchased in Japan. Later all models incorporated these carbon fiber speakers and also all the other drivers. Unfortunately, I had to pay to upgrade those. I will say that the difference in the presence, reality, of speech was dramatic. Most of the time my wife and I are unable to distinguish between the real phone ringing and the TV sound of telephones.
If there is one suprb investment to be made that improves the audio, it is an investmentt in low mass speakers.

I digressed---sorry. To sum up what Newton said--Objects tend to remain at rest unless acted upon by an outside force. Those walls only rattle if the low frequency is there to move them.

There's another thread about these things where someone posted a frequency response graph (not from a DD sub, it was from some software)before and after using the subdude. While it did seem to slightly flatten some peaks, it had the side affect of lowering output across the board, roughly 2-3db if memory serves. At its worst, youd need to double your amp power to get that output back.

Just saying that if i had rattles i would fix the window instead of tweak the sub. :)

John

Expletive,

Unfortunately,the dropoff in low frequency created by lifting speakers off the floor or out of a corner is not like lowering a shelf below lets say for the sake of this discussion, 100Hz. The dropoff becomes more pronounced as you go lower in frequency. The point is that when they designed and tuned the speakers, someone made a conscious decision about the speaker's frequency response characteristics based at least partly on their placement. One should not attempt to modify the manufacturer's design criteria AFAIC.

I had my DD-10 inplace for the past 2 weeks and the more it plays the more I enjoy it. I asked a number of questions a few weeks back and I would like to thank Curt and the others who responded.

My system is a combined music and HT system, but the DD-10 is used only for 2-channel listening. It is used with a Krell HTS7.1, a Cary 306 player and ATC 20-2 active speakers. The DD10 is connected with main L&R rca outs, while the speakers use the same XLR connections. They both get the same signal & I get the benefit of the analog bypass.

First - the sub is easier to setup in person than just reading the manual online.
Second- the EQ feature is invaluable. I knew my room had problems (12X11, opening to another 12X7 area), but its another thing to see how the room responds. The displayed showed a series a peaks and valleys with a huge dropoff around 50-60hz. This is such an abstract concept w/o the visual aid.
Third- its trial and error, changing the variables. I found the best results with the X-over at 80hz and a slope of 6 (yes 6). Changing the phase and polarity had no impact on the system response. I was surprised at the slope setting, however, given everything I read (higher generally be typical). I assume it just the best setting for my speakers in my particular room? The ATC's seem to cutoff sharply. The line (response) is still not straight, but fairly close.
Fourth- the results are great. Its amazing how well the sub integrates into the system. The bass response is strong, but subtle. It adds that lower dimension and a foundation to music w/o calling attention to bass response. I know there are skeptics, but this sub can truly integrate w/ monitors. I have gotten so acustomed to the sub over the past 2 weeks that I don't think I can have another system w/o one.

Once again, thank you for the assistance.

Raising a speaker somewhat off the floor is an interesting topic.

My mains ( Waveform Mach 17 ) each has 2 12" drivers, located right to the perimeter of the cabinet edges & bottom. A few months ago, I placed them on Symposium Ultra Platforms ( which are 3.5" thick ), and posted at how much cleaner things sounded, so I have run them that way ever since. They still play very low. I keep my DD-18 on the floor on its spikes, but my Contrabass siys on 2 cement blocks.

However, now with the DD-18 in-house, I will revist trying my mains directly on the floor again ( on stainless spikes ) run full-range with the DD-18 of , and see if the DD-18 can measure any changes. If the results are interesting, I will start a new post on the subject.

- Andy

Originally posted by curt c
No problem, no offense taken. I think you'll come to realize what a great bargain the DECO's are. We'll be off to CES this week.
Happy New Year to All!
Curt Hi Curt, am new here, I wil like your comments on chtr 12 I am planning to get for my 12ft x 17ft. room with 8 ft. ceiling and onkyo receiver txnr 900 and mission 783 speakers..thanks in advance, my other choice is mission 78 sub

Hi and Welcome,
The CHT-12R (US version is DLS-4000R) will do a great job for your room size. The remote makes preset selections and volume adjustments so quick and easy.
We're receiving a lot of positive feedback on the new DSP driven models.
Thanks,
Curt

Thanks for your insight.

Curt: I am a former regional manager with Boomer Mcloud a car stereo
franchise and I have listened to subs of all kinds on a daily bases
so I have become a little weary of that BOOM BOOM sound. Your subs are very clean and flat. I purchased a VX ten for my small den, it's about 1800 to 2000 cubic ft. (I am including the stair well) I was quite surprised with
this little subs performance, even at moderate levels it can vibrate the
walls sitting on a carpeted concrete slab! I know the roll off is around 35HZ
but I am curious as to what kind of extension it has. Also keep up the
good work, it's great you guys could come up with some high quality affordable subs. CHEERS.

Ian

Curt,

I am a long time Velodyne owner. Currently I have 2 subs - an older VA-1210 and a HGS-18 Series II. My question is about my Dad's system.

I recommended to my father a DLS-3750R, as it was in his price range. I am going to visit him shortly to help him set up his 2-channel system (he lives in another state). I was debating on whether to use the sub's crossover or use the preset crossover (80Hz) in the receiver (an 8 year old Denon). I am tending toward using the speaker level inputs on the DLS-3750R. This would give me greater flexibility and I am pretty confident that the sub's crossover is much better than the receivers. By the way the bookshelf speakers he has are the B&W DM 602 S3.

I am on the right thinking track?

Thanks for taking the time to answer my question.

Dan

Dan,

Pardon me for interferring but any time you amplify signal comung from the Speaker connections, you will have diminished dynamic range, a noisier signal and a greater risk of damage to the amplifier. In my 50+ years of playing with this stuff, I have avoided connecting anything but speakers to speaker terminals. I am sure Velodyne offers this path for convenience. It is certainly not the desireable path for fidelity.

Originally posted by Dan Schulze
Curt,

"I am a long time Velodyne owner. Currently I have 2 subs - an older VA-1210 and a HGS-18 Series II. My question is about my Dad's system.

I recommended to my father a DLS-3750R, as it was in his price range. I am going to visit him shortly to help him set up his 2-channel system (he lives in another state). I was debating on whether to use the sub's crossover or use the preset crossover (80Hz) in the receiver (an 8 year old Denon). I am tending toward using the speaker level inputs on the DLS-3750R. This would give me greater flexibility and I am pretty confident that the sub's crossover is much better than the receivers. By the way the bookshelf speakers he has are the B&W DM 602 S3.

I am on the right thinking track?

Thanks for taking the time to answer my question."

Dan

Hi Dan,
Since the older receiver is probably a Dolby Pro Logic unit it may not have enough output at the subwoofer output jack to run the sub. I would use a "Y" splitter into both sub input jacks. Try that method first. If there is not enough voltage to drive the sub, then your method is the alternative. Line level is preferable when available.
Thanks,
Curt

"I know the roll off is around 35HZ
but I am curious as to what kind of extension it has. Also keep up the
good work, it's great you guys could come up with some high quality affordable subs. CHEERS."

Ian [/B]

Hi Ian,
The VX-10 measures quite well down to 35hz and in certain locations lower.
Since our hearing is pretty well gone by 30hz, it's a fine performer for an economy subwoofer. Thanks for the positive feedback.
Cheers,
Curt

Curt: I keep reading discussions about the pros and cons of using two
subs on the AVS forum. What kind of results would one expect if they added another sub preferably the same as the original one?

Ian

Hi,
This discussion has and will go on forever. Two subs can support each other or interfere with each other. Certainly two subs of the same size, properly placed will be better than one. The real question is will two of a smaller size be better than one bigger one. Not an easy answer. Those who prefer smaller subs will go with a smaller pair. I usually start with a fifteen or eighteen and add a second one if necessary. But my rooms are very large. There are some who propose doing mode cancellation with multiple subs, that can work if you have placement flexibility. Our digital room equalization (DD subs) is a better solution in my opinion. As far as maximum output, two smaller subs will equal or surpass by a small amount the next larger size. That is two ten's will equal a twelve, more or less again depending on placement.
It's your choice.
Curt

Curt:
Thank you for your quick response. Ian Masters of Sound&Vision
said the same thing, but how does running two identical subs
relate to output in decibels since you are using twice the amp.
power? I assume two 150 watt 10's should have the same punch
as a 300 watt 12, or am I wrong? And does that translate into
a 3 or 6 db increase in output being that you are also moving twice the amount of air thus doubling your efficiency. By the way I demoed a VRP
1000 and 1200 and my 52 year old ears couldn't hear much difference.
Thanks again for your expertise.

Ian

Your assumption is all that amp power will or can be used. Too many people just look at watts. A driver (piston) can only be driven so far, regardless of the amount of power available. So you do the math, looking at the total mass of the piston and the excursion capability. The piston mass of two tens is just a little more than one twelve. You're right that two ten's would probably have the same punch of a twelve and maybe 3db more output under ideal conditions. But 3db isn't much louder. Twice as loud is usually said to be 10-12 db more. (Twice amp power is required for 3db additional output but that's not twice as loud) The output would be close to the same. If you demo'd the VRP-1000 and 1200 in a small room, you probably wouldn't hear much if any difference. In a large room there would certainly be a difference in output capability. When in doubt go with the larger unit. A little reserve is a good thing. Masters is always right.
Thanks,
Curt

Where I come from in the car stereo business multiple subs
and amps are almost a given and you realy ever have conversations
like this. Over kill is considered a good thing even if it cracks your windshield!
Anyway It really comes down to the size of the room. If you ever want to
hear some incredible spls come to one of our USAC competitions. Thanks
again and give my regards to Geoff Marks of whom I have the pleasure of
discussing my sound quality philosphy with. Cheers.

Ian

I have advocated this in the past. But I have good amps which are DC coupled and -very clean- in the low frequencies. I guess that I had forgotten about how capacitor coupled feedback loops can have poor low end extension and distortion. All the more so when the caps are electrolytic instead of film caps.

So I will try not to recommend this again without qualifications. But this does work very well if the amps are without the typical distortion and roll off that many?most mainstread amps do have.

Aragon 8008, WBTs and polyprop bypass caps on the powersupply
Conrad Johnson PV-5 modified, WBTs
MG-IIIa's, modfied x-overs
2x DD-15, connected to the amp speaker outs and phase aligned to the MG-IIIa's

(The PV-5 does not present a viable connection alternative, no buffered outputs)

Dan,

Pardon me for interferring but any time you amplify signal comung from the Speaker connections, you will have diminished dynamic range, a noisier signal and a greater risk of damage to the amplifier. In my 50+ years of playing with this stuff, I have avoided connecting anything but speakers to speaker terminals. I am sure Velodyne offers this path for convenience. It is certainly not the desireable path for fidelity.


Hi Dan,
Since the older receiver is probably a Dolby Pro Logic unit it may not have enough output at the subwoofer output jack to run the sub. I would use a "Y" splitter into both sub input jacks. Try that method first. If there is not enough voltage to drive the sub, then your method is the alternative. Line level is preferable when available.
Thanks,
Curt

Art & Curt,

Thanks for your quick responses.

Art,

I was not aware that there was additional amplification at the sub when using the speaker outputs from the receiver connected to the "speaker level inputs" on the sub, then hooking up the speakers to the "speaker level outputs" on the sub. I thought the speaker signal was just sent through the crossover in the sub. I will certainly use the line level "sub output" on the receiver, and hook up the speakers directly to the receiver, however I will probably do a bit of experimenting.

Once again thanks.

Dan

Sorry - duplicate post.

Dan

removed

happy

Hi Happy,
1) The amp and driver are the same.
2) The output of two fifteens and one eighteen would be in the same ballpark, so would the price. I'd go with the DD-18, you might surprise yourself once you see it's DSP capabilities.
Thanks,
Curt

Hello All...

Please note...This thread is used for Velodyne support and as such companies to other products should please not be made.

Above posts also edited by original poster.

Thank you.

Curt: This questions is simple: Since Velodyne strives for accuracy
do you think bandwidth uniformity is the best measurement to determine
that when looking at a subs specifications. After all the flatter a speakers
response is the more accurate it is.

I always think low distortion first and then flat frequency response. They are equally important. The problem with low frequency response is of course the room interface. That's why Velodyne developed the DD series subwoofers which are the best tool I've seen for dealing with room anomalies. With the on-screen review you can see what your real-time, in room response is.
Curt

David,

Your statement that "This thread is used for Velodyne support and as such companies to other products should please not be made." is very disturbing. I thought this was an open forum for discussing ideas. I know support is one of the issues often discussed but the idea that a manufacturer has a monopoly on what can be discussed in a forum is really quite repugnant. Knowing what I do of the Velodyne folks, I doubt they would want free thinking and speech curtailed. Please reconsider your position limiting free thinking. It does not sound like you and it is extremely repugnant. Integration with other devices and comparison with competing brands and technologies seems appropriate and desireable. IMHO the lack of free speech is what killed Sterophile magazine. In the days of J. Gordon Holt, we were exposed to inexpensive and expensive devices in Stereophile Magazine. Later it catered to those who took out big adds. I canceled my subscription. I would hate to lose the privilidge and joy of these discussions because the forum became a mouthpiece for the manufacturers.

I agree some what. Sometimes you have to talk about other manufactures
subs in order to make a point. Asking Velodyne about an SVS sub
helps clarify the differences in the TYPE of subs they make. I would never say anything about another make that was negative and the Internet comment may have been inappropriate but comparing or having questions about the designs were not. But you're the boss and I respect the fact that it's your call.

Ian

Originally posted by MrHifi
David,

Your statement that "This thread is used for Velodyne support and as such companies to other products should please not be made." is very disturbing. I thought this was an open forum for discussing ideas. I know support is one of the issues often discussed but the idea that a manufacturer has a monopoly on what can be discussed in a forum is really quite repugnant. Knowing what I do of the Velodyne folks, I doubt they would want free thinking and speech curtailed. Please reconsider your position limiting free thinking. It does not sound like you and it is extremely repugnant. Integration with other devices and comparison with competing brands and technologies seems appropriate and desireable. IMHO the lack of free speech is what killed Sterophile magazine. In the days of J. Gordon Holt, we were exposed to inexpensive and expensive devices in Stereophile Magazine. Later it catered to those who took out big adds. I canceled my subscription. I would hate to lose the privilidge and joy of these discussions because the forum became a mouthpiece for the manufacturers.


David is not limiting free speech ON THIS FORUM. He is only limiting the type of discussion IN THIS THREAD. If you want to discuss other companies products, start another thread -- or PM the Velodyne guys directly. Its hardly fair to ask the Velodyne guys for information or opinions about other companies products in a public forum.

You WAY overreacted, man.

Craig

What craig john said.

I agree with that.

Hey Curt: How come you don't use insulation in your rear port subs?
Also do flared ports really reduce port noise?

Ian

Gentlemen,
I have a Velodyne F1500R that has developed a problem slowly over the last couple of years but now is almost unusable. When playing loud,or with a lot of LFE coming in (mostly from music,it has to sustained,not intermittant like from a movie soundtrack) it will shut itself off or rather go into standby for maybe 10-15 seconds then come back online (with the front LED flashing). I know this is a safety feature on this sub,but now it happens all the time at lower volumes than I used to play it.. The back of the sub,(amp) feels very hot,but honestly don't know if it's hotter than when everything was working properly. Does anyone know what the cause may be? Perhaps there is something wrong with the internal amp?
I'm in Illinois and don't know where I should take this to be looked at or if it's even repairable. Tried emailing Velodyne support but no response.

Thanks for any help.

slapshot...........

Just give them a call. They are very helpful.
To their detriment, I have never received an answer to an Email I have ever sent them. May have just been bad timing???

Hi,
It looks like we've had some email issues. I'm sorry for that. Emails to service should go to; service@velodyne.com. We do have a new server and that should help. The telephone numbers for service are listed on our website; www.velodyne.com.
Curt

My last question: No answer?

Originally posted by mailiang
Hey Curt: How come you don't use insulation in your rear port subs?
Also do flared ports really reduce port noise?

Ian

Sorry for the delay, I was getting some information.
The VRP series have a 3.5" diameter rear port that is flared with .5" radius on the edge. Flared ports do reduce port noise. Insulation would reduce the amount of output at the port.
Curt

Does it help to flare the inside of the port?

Flaring ports is something that was done for esthetics in the days of Bass reflex speakers. Plain old tubes and square ports work equally well whenthey're tuned properly. DO NOT PLUG THE HOLE!!!!!!!!!!!

OF COURSE NOT! Thanks Art. We will see if Curt agrees. Cheers.

Ian

I agree.
Curt

Curt: It's been slow on this post lately so I thought I'd give you
something to contemplate. Here is some data from two reviews of two Velo. subs by Tom Nousiane: DPS-12: Bass limit 20hz at 80db.
Average spl 25-62hz:103db
Max.spl 110db
Bandwith uniformity 94%
Price:$549.00


DD-12: Bass limit 20hz at 78db
Average spl 25-62hz:104db
Max. spl 109 db
Bandwith uniformity: 95%
Price:$3000.00


Max distortion allowed:10%



If you look at these specs you would think it was the same speaker.
Ok now, your thoughts, do your sales pitch for me.

Ian

PS: I just love playing devils advocate with audio manufactures, after all
I had to do it for a living.

Hi folks,

I have an older ct-80 that has developed a problem over the past few months. I leave the sub in standby mode. When it detects a signal, the light changes from red to green, but the sub doesn't always work. Sometimes I have to turn the power off and back on to get sound. After the power has been recycled, the sub works for the rest of the evening.

Is this something that can be fixed?

BTW - I have the sub hooked up direct - just for fun I tried plugging into the right and the left inputs. It makes no difference.

Curt,

It sounds like you learned your basics like I did. Did you have any formal training in Acoustic theory and Engineering? In college, I majored in Physics with specialties in Acoustics and optics.

In the '90's when I was looking for a sub to use for the Dolby Digital LFE channel, I was attracted to the Velodynes based on what I read about the design principles. I loved the idea of contolling overshoot with the servo system. At the time, I was using feedforward loops to control a variable slip tire testing machine. The idea applied to my hobby was too much to ignore. I ordered my F1800 without ever hearing it. Except for the hum, I loved it. Sending it back was out of the question because of the weight so I' ve lived with it for nearly 9 years. I think you guys should send me a new amp. I'll return the old one but if I have the new one here, I'll only have to hire someone to move it and disassemble/assemble it once. I have several very heavy ADCOM monoblocks on top of the sub. Please email me if we can work something out. I've enticed a lot of people to buy your subs over the years based on their listening experience in my home. How about cutting me a break? Perhaps you might even have an update of the amp. I have no desire to pull the 18" driver. Does the amp come out from the rear or do you have to remove the driver in the front to get it out? BTW, if you say no, I'll understand.

mailiang,

Any way you can provide a link to Nousaine's reviews???

thanks,

Randy

Curt: It's been slow on this post lately so I thought I'd give you
something to contemplate. Here is some data from two reviews of two Velo. subs by Tom Nousiane: DPS-12: Bass limit 20hz at 80db.
Average spl 25-62hz:103db
Max.spl 110db
Bandwith uniformity 94%
Price:$549.00


DD-12: Bass limit 20hz at 78db
Average spl 25-62hz:104db
Max. spl 109 db
Bandwith uniformity: 95%
Price:$3000.00


Max distortion allowed:10%

>>>>>>>>>>>>>>>>


WOW! Either the DPS puts out some amazing numbers or the DD-12 put out some poor numbers.

Amazing.

-Brian

Ian, Brian and Randy,
To set the record straight, Tom Nousaine reviewed the DPS-12. He never reviewed the DD-12. The DD-12 was reviewed by Dan Kumin and Tom took the measurements. (Tom normally uses a 7000 cubic foot room for his measurements which of course is not where one would place a DD-12.) They both work for Sound & Vision magazine. As you can see both sets of measurements are very fine indeed. BTW Dan chose to keep the DD-12 as his on-going reference subwoofer.
As most of you know, the two units are very different in design and function.
The DPS is an (upper) entry level product in a fairly large enclosure using a bass reflex design. This high efficiency design gives it a head start as far as output goes when compared to a small sealed enclosure. In a "bang for the buck" arena it offers outstanding performance for the price. It also has a DSP input section for added flexibility.
The DD-12 is a small sealed box designed to fit into tight quarters and not call attention to it's size. Placed in the appropriate size room, it is state of the art. It will measure and perform better than any other subwoofer in it's size group. The DD's come in 10,12, 15 and 18 inch driver sizes so there is a model for most any application. The DD's all have servo control which is the most sophisticated and expensive way to control cone motion. Distortion is usually well below 2%. By now you all probably know they have an "on board computer" for real-time equalization. They have almost unlimited set-up capability. The DD's are considered by most in the industry to be the reference. The one which others will be judged against. Larry Greenhill (Stereophile Magazine) considered by most to be the expert on high-end subwoofers uses a DD-18 as his reference. The DD's are being saluted all over the world as a major achievement in subwoofer performance and design.
So for those on a budget, yes the DPS (and DLS) subwoofers offer great performance.
For those who want it all, those who can appreciate the differences, even the subtle differences, when only the very best will do, Velodyne proudly offers the DD series. It is the most accurate subwoofer I have ever heard. I have been playing with "bass boxes" for over fifty years and let me assure you the technology of the DD subwoofer is not currently available anywhere else at any price.
Curt

Originally posted by MrHifi
Curt,
" Does the amp come out from the rear or do you have to remove the driver in the front to get it out? BTW, if you say no, I'll understand. "

Art,
I just sent you a PM. I've sent you a couple in the past. Do you check and open your PM's? The amp comes out the rear.
Curt

Curt,

Are you saying the numbers are not "apple to apple"? In other words, are the numbers listed correct?

-Brian

I would imagine that the DD12 should have an advantage in THD at all frequencies, thats the trend ive seen between ported and sealed cabinet designs (especially with servo). Based on the reviews ive read that measure this, the DD series is the best ive come across (for a subwoofer). Not sure waht bandwidth uniformity is tho, is that a measurement of THD? (Disclaimer: I am no expert. just an enthusiast with too much time on his hands to read audio reviews and spit them back out on forums!)

All that said the i think DD12 will be much more flexible in its placement due to the EQ and i have found the presets to be invaluable! Now i can enjoy music AND movies the way i want to without having to compromise on either, its a real joy.

Curt, does a DD sub need time to 'break-in'? I just got one and was just wondering if it did, and what kind of material you would reocommend to do it (if it does need to).

I've got some friends coming over for the game later today and want to make sure its ready to go. :D

John

Hi,
Bandwidth uniformity means how flat the frequency response is.
The DD does not require a break-in period. Use it, enjoy it. I look forward to the game today too.
Curt

Originally posted by curt c
Use it, enjoy it. I look forward to the game today too.
Curt

Great news. Thanks for the 'Superbowl Sunday' reply, you guys at Velo are great.

John

Curt your even older then ME! I didn't know you worked on Sundays.
Is there anyway we can get Tom to join our forum? It would get
real interesting. By the way, I personally think that the DLS 5000R
is the best sub you can buy FOR THE MONEY. Have a great super bowl
Sunday.

Ian

For some reason the PM's do not get to me from these Yahoo forums. I can be reached at aneilljr@comcast.net.

Hi Curt,

Just bought velo chtr-12 pairing it with onkyo txnr900 and mission 783.

No problem with HT, but with cd playing the bass seems to be weak, how long is the break-in period, my crossover is at 80hz, or any suggestion to improve usage of this fabulous sub? some suggested 50-60hz crossover for audio listening?

Hi Curt,

BTW, what is the suggested phase 0, 90, 180 or 270 degrees? I have a room size of 12feet x 17 ft. My local retailer suggested 0 ? Pls. give suggestion for ht and audio listening...thanks again.

Hi,
Put the phase at "0". If your calling your front speakers "large" change them to "small". Many receivers won't send bass to the subwoofer while playing music if you've called them "large". I'd designate all your speakers as "small" and see if that solves the problem. If not have someone check your receiver or contact Onkyo. There is no break-in period for the Velodyne. 80hz is a good crossover point for most speakers using a 6" woofer. Hope this helps.
Curt

Originally posted by curt c
Hi,
Put the phase at "0". If your calling your front speakers "large" change them to "small". Many receivers won't send bass to the subwoofer while playing music if you've called them "large". I'd designate all your speakers as "small" and see if that solves the problem. If not have someone check your receiver or contact Onkyo. There is no break-in period for the Velodyne. 80hz is a good crossover point for most speakers using a 6" woofer. Hope this helps.
Curt So to sum it up, is it better to put front speakers at "small" regardless of home theater or audio (cd) listening? Because our retailer here suggest that for home theater use small, since excess will be taken cared of by sub, while for audio listening they suggested "large" for fronts since for audio listening we normally dont use the sub? Sorry am quite confuse can you enlighten me again? BTW, is the crossover at my sub bypassed if I have set it at my receiver?

Hi Curt,
As per chtr user manual, its says, you may want to bypass the crossiver in either the processor or the velo sub. In some cases you want to use Both crossovers. To do this, you can use both processor's crossover and the one internal to the velo sub. (ie., 120hz subwoofer, 80 HZ processor) for best results.

To bypass the subwoofer's internal crossover when unit is being fed a low pass signal, turn to DIRECT position on the rear panel, this will eliminate the internal crossover from the signal path....

Yes I am suggesting you use your speakers set at "small" for both music and H/T. Have your receiver crossover at 80hz and put the subwoofers crossover at "direct".
Curt

I am upgrading my HT. I recently bought two DD-15 for the front of my theater. The guy designing my theater suggested adding two small subs in the back of the theater because it has a raised platform that is “live”. My theater is 16" X 23" and is over my garage. Can this setup work & how would I calibrate the subs.

Hi,
I would start with the two DD-15's since they should provide more than enough bass. The "live" should not be an issue for bass response so I'm not sure what he means. If you use additional subs in the rear then you would calibrate one of the DD-15's with all the other subs playing.
Curt

Curt, I am looking for a pair of subwoofers I can cross over to a pair of high-quality monitors at a higher than normal frequency, say, 140Hz or 150Hz. I wouldn't need DSP and the room is a bit less than 2,600 cu. ft. Would the HGS-12X be appropriate?

The HGS 12X with it's crossover bypassed will go up to about 120-140hz where it rolls of naturally. The crossover on the HGS series is 40-120hz. One customer used it with some ribbons (in the bypassed mode) that went down to about 150hz and he said it worked fine in his room. It's one of those things you would need to try. The DD series with the digital crossover can be taken up to 199 on the low pass and you can see the integration with your monitors. I'd go with the DD-12 if possible. Once you see what the DD can do, there's no going back.
Curt

Curt,

I recently bought a DD-15 and was trying to update the firmware via serial cable. I downloaded the latest (v1.6) and I have V1.5 on mine (build in Oct'04). The update appreared to be running fine (completed without error) but when I checked on screen, it still shows as version 1.5 on the top left hand corner of the screen (in the main Velodyne DD). I ran the update twice (to rule out system glitches) but to no avail. What gives? Thanks,

Frances

Hi Frances,
Which serial cable were you using? It has to be a mouse extender cable. A modem cable will not work. A couple of pins are reversed on the modem cable. We have the proper cable if you can't find the right one.
Thanks,
Curt

Curt,

thanks for the quick response. I used the mouse extender, and a converter from USB (PC side) to RS232. So, in essence, the path is: USB-serial converter, mouse extender serial, and the female on the sub. One thing that potentially (at least in my mind) might interfere with the process is, I used a male-female adapter (on the sub side) due to the fact that the female port on the sub, has the side-screw holder (which is atypical for the female socket). What it does, it requires a removable side-screw on the male socket, which is not common (with Belkin off-the-shelf extender from Compusa). If this is not proper, then I would definitely be interested in getting yours. Thanks again,

Frances

I'm curious, why use a serial cable on the DD's these days when serial ports are disappearing from computers and USB and firewire are clearly faster (and arguably better) choices for transmitting data?

In a similar situation, I had to get a USB to serial converter for my laptop to load maps to my GPS unit because none of my computers have serial ports any more.

Is there a technical reason for using a serial port on the DD's?

Originally posted by fhidayat
Curt,

thanks for the quick response. I used the mouse extender, and a converter from USB (PC side) to RS232. So, in essence, the path is: USB-serial converter, mouse extender serial, and the female on the sub. One thing that potentially (at least in my mind) might interfere with the process is, I used a male-female adapter (on the sub side) due to the fact that the female port on the sub, has the side-screw holder (which is atypical for the female socket). What it does, it requires a removable side-screw on the male socket, which is not common (with Belkin off-the-shelf extender from Compusa). If this is not proper, then I would definitely be interested in getting yours. Thanks again,

Frances

This may be a stupid suggestion but make sure you are connected to the RS-232 IN and not OUT. I connected it to OUT and the software ran and said it had completed successfully but the sub was not updated. I then realized last time i updated i used a different serial cable with an adapter, it worked fine. When its working correctly, the amber line and blue velodyne logo will intermittenly blink fast during the upgrade process.

John

thanks, John. I am pretty sure that I plugged into the IN port. It's the top socket (if recall correctly). You mentioned a good point though, I got only the amber light. Hmm, I should try again this weekend.

Originally posted by Gilley
I'm curious, why use a serial cable on the DD's these days when serial ports are disappearing from computers and USB and firewire are clearly faster (and arguably better) choices for transmitting data?

In a similar situation, I had to get a USB to serial converter for my laptop to load maps to my GPS unit because none of my computers have serial ports any more.

Is there a technical reason for using a serial port on the DD's?

There's no good reason, just the design decision we made when we laid out the board some three years ago now. In the next hardware revision for DD we will update that feature to USB. How cool will it be to plug in the DD and have a balloon message pop up that says : "Found new hardware: Velodyne Subwoofer" :cool:

Hope this helps,
Bruce

Bruce,

I just picked up a DD15 today and am in the process of optimizing placement. First of all let me say wow! :) I have a two-channel audio system as well as a HT system in the same room. I'd like to use the DD15 for both but I have a preamp and a prepro. How do I hook both up to the DD15? I noticed the DD15 has both an XLR and RCA input jack - do they autioswitch or does one override the other input?

Thanks,

Bob

Originally posted by BruceHall
How cool will it be to plug in the DD and have a balloon message pop up that says : "Found new hardware: Velodyne Subwoofer" :cool:

Hope this helps,
Bruce

That would be cool indeed! Thanks for the reply, Bruce. It was just curiosity on my part.

Keep up the work on cutting edge technology.

Bruce,

Will the stand-alone unit be USB or RS 232? Thanks.

Craig

Originally posted by bob53
Bruce,

I just picked up a DD15 today and am in the process of optimizing placement. First of all let me say wow! :) I have a two-channel audio system as well as a HT system in the same room. I'd like to use the DD15 for both but I have a preamp and a prepro. How do I hook both up to the DD15? I noticed the DD15 has both an XLR and RCA input jack - do they autioswitch or does one override the other input?

Thanks,

Bob

Hi Bob,
All inputs into DD are summed together. Just hook the two channel and the HT system into different inputs (the XLR and LFE in, for example). This should work fine. The only caveat is if you run the same signal into two different inputs and they are out of phase - in this case they will cancel each other out. But with two different sources running at different times you are fine.

Hope this helps,
Bruce

Originally posted by craig john
Bruce,

Will the stand-alone unit be USB or RS 232? Thanks.

Craig

Hi Craig,
Sorry, RS-232. The SMS-1 is pretty much exactly the DD control board and most of the software...

Bruce

Hi,
Since you mentioned the older ULD's, how would you compare the ULD 15 to the current models? I have a ULD 15 that has worked wonderfully for the past 10 years.
Thanks in advance,
Joe H

Originally posted by curt c
Hi Eric,
The original Velodyne's, the ULD series were all down firers. It was mainly to get it past the wife as furniture. Subwoofers weren't very popular then. Fortunately things have changed. We made these units from the early 1980's through the middle 1990's. Since then it's been all front firing.
There are currently three DD-18's out for review and a couple of 12's. John Johnson has an eighteen and should have his review on line very soon.
Thanks,
Curt

Joe,
The main thing you would notice is the reserve output capability. The current DD-15 (or HGS-15X), can play much louder at even lower distortion levels. More output has become a definite requirement with the advent of home theater. In the "old days" of music, we had to deal with an occasional low "C", now we have really loud explosions and sustained rumbling effects that put a tremendous strain on the subwoofer. In the last twenty years, Velodyne has made tremendous improvements to both driver and amp design. The ULD's were state of the art in 1982, and beyond. The DD's are state of the art now and the foreseeable future.
Thanks for the question,
Curt

Curt : With the advent of home theater, space is becoming a major
issue for a lot of people. What subs do you recommend that are smaller
and more practical but produce the kind of results that the bigger ones do?
Also, how do they accomplish good deep bass output, low distortion, etc.

Ian

Also, how do they accomplish good deep bass output, low distortion, etc.

Mailiang,

Over at "Secrets of Home Theater and High Fidelity", John E. Johnson, Jr. does a very informative and interesting interview with Bruce Hall. I believe it will answer your questions. I know I learned a lot listening to Bruce. The file is huge, 50MB, but well worth the download.

Bruce Hall Interview (http://www.hometheaterhifi.com/videos/secrets-studios/bruce-hall-velodyne-2-8-05/bruce-hall-velodyne-2-8-05-index.html)

Bruce - thank-you for explaining servo-feedback systems. I was glued to the computer screen!!

Dan

Guys, I just bought a Velodyne DPS-12 sub and I have a couple of questions...

1) How do you turn Night Mode OFF? When you press the button on the front panel the light toggles from bright to dull but it never goes off completely? Does Bright=ON and Dull=OFF or what? The manual does not specify.

2) When you power the sub OFF from the back, then turn it on again later, does it keep the same volume level? Or if you actually unplug the sub does it loose it's volume setting then? I really hate that the volume control is digital rather than a regular knob on the back. I would like to know what my volume is at a glance. On the DPS-12 there is no way of knowing what volume percentage you are at.

3) Not really a question, but a complaint if anyone from Velodyne is reading... on my sub the little cardboard DPS-12 sticker/sign that is attached to the front panel was actually GLUED SOLID to the grill material on the back of the panel. Even though I tried gently to remove it I pulled some of the grill material from the frame. There was no other way to get it off. Can you please just HANG that cardboard sign there rather than GLUE it? Hopefully mine was a packaging error and not all of them are like that. I have it on a 30 day trial and will be getting the front grill replaced if I do decide to keep the sub.

Any info appreciated. Thanks!

Dan: Just saw the interview, Very informative and sheds a whole new light
on speaker design. Coming from the car stereo business I have gotten so
tired of all that BOOM. It so refreshing when I listen to Bruce talk about
sound quality and accuracy. It confirms my philosophy : "Louder is not always better" Thanks for the heads up.
And Bruce: Thanks for your insight, your helping to move this industry in the
right direction with some great speakers.

Ian

Since no one else will ask:
How much longer for the 2.0 firmware for the DD series?
TIA

Originally posted by cajunlab
Since no one else will ask:
How much longer for the 2.0 firmware for the DD series?
TIA

Hey Cajun,
In beta test now, expect release next month...

Bruce

Bruce: I was on another thread where a forum member mentioned that he could get a deal on a DD 12 and wanted to know if it had enough output for his 20x12 ft. room. I thought the 12 would be more then adequate but many members suggested he should consider the DD 15 or 18 instead. I know you can never have too much bass, but am I being too conservative,
or am I just too old school?

Ian

Originally posted by mailiang
Bruce: I was on another thread where a forum member mentioned that he could get a deal on a DD 12 and wanted to know if it had enough output for his 20x12 ft. room. I thought the 12 would be more then adequate but many members suggested he should consider the DD 15 or 18 instead. I know you can never have too much bass, but am I being too conservative,
or am I just too old school?

Ian
Ian:

Thanks for the cross-thread bump on my question. Nice here how the members look out for each other :) .

John

John: I quess we'll both be waiting for his answer. At least now I won't
need to foward it. Cheers.

Ian

Yes, very cool of you Ian to take this question to the source. I did a quick search on this thread to see if a similar question had been asked and answered. Turns out Curt c hesitatingly answered a general question regarding room size that may apply here:
Originally posted by curt c
Neil,
I wish it was that simple. So many variables. We are revamping our Website and will attempt to do what you're requesting. Room size, openings into other rooms, types of music/movies, how loud all come into play. I often suggest cheat up (bigger) or the largest unit you can budget. Most end up with a subwoofer that is too small, often much to small and then they push it to hard, just as theranman states.
Against my better judgment, I today will offer the following. I may change my mind tomorrow. (My Disclaimer)
Small Rooms (to 1800 cubic feet) DD-10 or DD-12
Medium Rooms (to 3000 cubic feet) DD-12 or DD-15
Large Rooms (over 3000 cubic feet) DD-15 or DD-18
If rooms have openings into other rooms, then all those rooms must be counted in the measurement.
We are going to do our best to put some science to this issue.
Hope this helped some.
Curt
So assuming John has 8' ceilings (we know the 12 x 20 part) and it is an enclosed room (I think it is, John?), that would put his room at a total of 1920 cu. feet, since it's closer to the small room category (though still in the medium room definition) one would guess the DD-12 would do just as Ian suggested.
However, the part that caught my eye (and was cautioning John about) was this: "I often suggest cheat up (bigger) or the largest unit you can budget. Most end up with a subwoofer that is too small, often much to small and then they push it to hard, just as theranman states."
Which of course hints that the DD-15 would be a safe way to go.

With all that said, knowing that John is not interested so much in dramatic movie effects, the DD-12 would probably do, again as Ian suggested.
My only point was I wouldn't want John to be one of the many that end up with a "subwoofer that is too small".

It will be interesting what Bruce's take is.

Best Regards,
Patrick

Originally posted by avaholic

So assuming John has 8' ceilings (we know the 12 x 20 part) and it is an enclosed room (I think it is, John?)
Guys, thanks again for all the help! Ceilings are 8', except back 1/3 of the room has a riser for the second row of seats that makes the ceiling there 7'3". Since this is one of 3 subs in the room, I'm hoping that the DD-12 (which I just pulled the trigger on :) ) will work fine. My other 2 sub amps have adjustable phase, so I'll be interested to see the interplay between those 2 knob positions and the EQ curve...

John

John,

Per your thread, with the added knowledge that you are using those RBH sub modules (as stands for your mains) for LFE duties also, the DD-12/submodules will likely be more than enough! I believe the DD-12 EQ will allow you to EQ all of the subs for a better FR curve, if I'm not mistaken. Maybe Bruce or Curt can chime in and give you specifics.

You are going to have one Kick-A%% system!

Best Regards,
Patrick

John and Patrick,
You will EQ the DD-12 with all the subs playing. While the DD cannot EQ the other two subs, you will EQ the DD for total bass contribution (including the other two subs) with the mic at listening position. And yes you should experiment with the phase of the other two subs and see what effect it has on the curve. If possible, also experiment with location of the subs. The flatter response you have in the beginning, the easier it is to EQ.
Curt

Originally posted by curt c
John and Patrick,
You will EQ the DD-12 with all the subs playing. While the DD cannot EQ the other two subs, you will EQ the DD for total bass contribution (including the other two subs) with the mic at listening position. And yes you should experiment with the phase of the other two subs and see what effect it has on the curve. If possible, also experiment with location of the subs. The flatter response you have in the beginning, the easier it is to EQ.
Curt
Thanks, Curt. I should get the DD-12 in a week or so. I'll report back regarding my initial thoughts...

John

Originally posted by curt c
John and Patrick,
You will EQ the DD-12 with all the subs playing. While the DD cannot EQ the other two subs, you will EQ the DD for total bass contribution (including the other two subs) with the mic at listening position. And yes you should experiment with the phase of the other two subs and see what effect it has on the curve. If possible, also experiment with location of the subs. The flatter response you have in the beginning, the easier it is to EQ.
Curt
Thanks for correcting me Curt. I think I misunderstood another members post as to how it can help you if you have multiple subs. If I remember right you can view the other subs FR response individually with the EQ, is that true? Or am I misunderstanding again?

Best Regards,
Patrick

Patrick,
You can view what the mic picks up. So if you had the volume down on the DD and played another sub you could view it. You can only EQ the DD. You might notice Larry Greenhill (Stereophile Magazine) does this to view other subs responses.
Thanks,
Curt

Hi,

I wonder what's the idea behind Velodyne's suggestion in EQ ing while in "Stereo" mode?
I read in one of the posts that it's supposed to be easier for some reason.

I don't use "Stereo" mode on my Lex MC8 at all. I use Logic 7 film for 99% of my viewing.
In my case should I opt to EQ while in Logic 7 film?

Multiple EQ curves will sure be handy.

Thanx
Ran

"I wonder what's the idea behind Velodyne's suggestion in EQ ing while in "Stereo" mode?"

Yes I wonder about this as well. I have the DD15. If you're using a processor, have your mains set to small and blend the sub perfectly with the mains with a stereo signal, well that's well and good for stereo. You may find though that ideal sub setting in this situation is a low pass frequency of say 60Hz with say a 24dB per octave roll off above this. That would then mean when watching movies, the dedicated sub channel (the 0.1 channel) would then be filtered in the same way and you'll end up losing significant bass above 60 Hz.

I think the only way to do it properly is to disconnect the mains and equalise the sub on its own, flat up to say what Dolby says the sub channel should go up to (120Hz?). Then if you have a fancy enough processor, use it to equalise the mains and sub combo for stereo performance, and hopefully the processor is smart enough to still send the full 0.1 sub signal to the sub for movies. Does such a processor exist? I'm only doing 2 channel at the moment so its not really a problem thus far.

Originally posted by obiwan
I think the only way to do it properly is to disconnect the mains and equalise the sub on its own, flat up to say what Dolby says the sub channel should go up to (120Hz?). Then if you have a fancy enough processor, use it to equalise the mains and sub combo for stereo performance, and hopefully the processor is smart enough to still send the full 0.1 sub signal to the sub for movies. Does such a processor exist? I'm only doing 2 channel at the moment so its not really a problem thus far.

The Integra Research RDC-7.1 allows setting the crossover point between 40 and 150 Hz for each pair of speakers plus it has an LPF for the LFE channel. The sub can also be set to LFE only when running the main speakers as large. I think that meets the requirement in your question. The processors from Lexicon and Meridian also have very flexible bass management and probably have similar capabilities.

Brian

The Integra Research RDC-7.1 allows setting the crossover point between 40 and 150 Hz for each pair of speakers plus it has an LPF for the LFE channel. The sub can also be set to LFE only when running the main speakers as large. I think that meets the requirement in your question. The processors from Lexicon and Meridian also have very flexible bass management and probably have similar capabilities.

This still leaves the problem of only being able to use the DD's sliders on one setting only. So you have the choice of having the sub/mains combo flat for 2 channel or have the sub flat for the LFE channel. Actually I've just remembered, and it probably has been discussed in this huge thread earlier on, the other way of doing is to configure the processor to say you have no sub, have the mains set to large, but send the RCA signal of the front R and front L to the sub and then send the hi-passed signal from the sub to your power amp for the main speakers. THen once you equalised the sub for 2 channel it would be automatically be equalised for LFE channel as well.

Is the concern that the LFE will be too loud above the LPF of the mains? I thought there were four presets or so in the DD series, selectable with the remote. If so, you could reduce the output in the range between the different LPF values for one of the presets and set it flat for another.

Also, I'm unsure what happens to the HPF from the LFE channel. Either it gets dropped or perhaps it gets sent to the mains. The LPF of LFE should only be routed to the mains when setting the sub to "off" and when the mains are set to full band.

There is also the option to skip all of those settings and just use the HPF in the sub for running the mains, as you mentioned.

Brian

I have a DD-18 in a rather large room, 23 X 23 w/ vaulted ceilings and plenty of openings to other areas. I have the sub in the corner about 13 feet from my couch.

Despite playing w/ several different settings I have been unable to get a satisfactory response in the subjective "WOW" category. Sometimes the sub just does not feel that powerful.

This may be an obvious question but would moving the sub closer to my couch provide a more powerful response? Or once calibrated would they "feel" the same?

Secondly, would an RCA interconnect of 25-30 be to long (as I would have to run it along the mopboards)? I would not want to lose signal strength.

Thanks.

-Brian

Brian,
As noted in the manual, after calibration you may need to raise the volume of the subwoofer as human hearing drops off considerably below 100hz. I would suggest you experiment with placement. Interconnect runs 25-30 feet are acceptable. Many large, open areas require two or more DD-18's. It appears to me counting all the openings you may have over 10,000 cubic feet. That's huge. Keep the sub away from any of the openings. You might want to give me a call to get into specifics related to your installation.
Thanks,
Curt (480) 595-7141

Curt,

I think he needs a couple of the JBL free standing Imperials we talked about.

Brian,

what Curt just said is extremely important. All the calibration curves in the world can not simulate the low end rolloff of your ears. a roloff defined as such by the measurement standards and technology available to us. most of the early stand alone Pre/Pro's and Dolby decoders recommended boosting the low end LFE channel by +10 dB. I do that sometimes but mostly rely on my ears. one must understand that what is going on in these subs is not magic. It is a flat mass of material being pushed through the air in order to excite that air sufficiently to affect your eardrum to the extent that is pleasing vis a vis other frequency inputs and at whatever level you and your neighbors are able to tolerate. If you try to use the curves and the EQ by itself I guarantee you will be disappointed. Enjoy the technology but please do not get lost in the numbers.

Originally posted by obiwan
This still leaves the problem of only being able to use the DD's sliders on one setting only.

We can solve this one, anyway.

Version 2.0 of the DD software should be available for free download by the end of the month. In it, each preset can have it's own set of unique EQs (sliders). Unless of course you mean White Castle sliders...:p

Bruce

Excellent Bruce

Originally posted by MrHifi
All the calibration curves in the world can not simulate the low end rolloff of your ears. a roloff defined as such by the measurement standards and technology available to us. most of the early stand alone Pre/Pro's and Dolby decoders recommended boosting the low end LFE channel by +10 dB. I do that sometimes but mostly rely on my ears.
Actually that has nothing to do with Fletcher-Munson curve and our ears. Check this (http://www.genelec.com/support/faq/faq40.php) link. Old decoders were not designed correctly and they didn't have this 10dB boost, which all modern decoders have now. "House curve" is the one you're meaning and it's used to compensate our hearing (sensitivity drops strongly below 200Hz).

F-M curve: http://www.allchurchsound.com/ACS/edart/fmelc.html

Hi,

I just bought a DD-18, beautiful unit, and I just have a few question about setup and connections :)

I have it hooked up to a Yamaha Z9, with the setting of a ‘monaural’ signal output. (not ‘stereo’, not ‘front and back’).
Now, first, the Yamaha has left and right LFE pre-outs, as it can accommodate two subs in Stereo/FrontAndRear sound fields.
Do I just connect my sub-woofer cable to ONE of these outputs on the Z9, and then use a Y-splitter cable to connect the other end of the cable to the TWO inputs on the DD-18?
Or can I have my Z9 outputting a Monaural LFE signal through both of its pre-out and connect a separate cable for each left and right pre-out, into the DD-18's left and right inputs? Or does it not really matter, and the effect will be the same?

My second question is:
The DD-18 is a THX Ultra 2 certified sub, and the Z9 is also THX Ultra 2 certified, so in the Z9 there is a setup option which asks if your connected subwoofer is a THX Ultra 2 compatible sub.
What exactly does the amplifier then do if I say YES, or if I say NO to this option. The manual does not really state what this setup feature does. Should I set the Z9 to YES, or NO, and what difference will I hear, or what things is it doing different to the signal?

Thankyou
Cheers
KJ

KJ,
1) I doubt it would make any difference. Either way should work fine.
2) You might want to check with Yamaha on this or perhaps some other users may know. It might have to do with the amount of output voltage the Yamaha sends to the subwoofer jack or perhaps they engage a subsonic filter for the non-THX Ultra II subs.
Any one know for sure?
Curt