* Offical Velodyne Support Thread * - Page 11

Curt,

What is the Q value or range of Q values for the DD-10 sub? And the others?

thanks,

Ran

This may seem slightly ridiculous, but here goes.

I have a smallish room (1500 ft³) and an F1500. It is almost as if I can't set the volume low enough on the sub, there always seems to be a ton of bass (lots is good, but this is way too much). When I calibrate it and the rest of my speakers to 85db, the sub is only set to "2" and I still feel like I need to set the receiver to -2 to -4 db to control the amount of bass. I'm not hearing distortion, it's just overpowering the hell out of my speakers.

Is an F15 just too much sub for this room, or is there possibly something wrong with it?

Hi,
There's nothing wrong with having the volume low on the sub. Just decrease the output on the receiver, -2 or -4 or lower if necessary. Normally the issue is just the opposite so enjoy having all that reserve.
Curt

Thanks, Curt, for your feedback re "dueling" crossover. I've been trying to figure this out for awhile now.

If I understand correctly, I can defeat my receiver's crossover (which can be turned "off"), and rely entirely on the sub (I have a DD10) to handle the crossover, without interfering with my receiver's other BM functions (i.e., "small" vs. "large" speaker settings).

I tried this, and my Avia test disc revealed LFE running to my left front speaker. Is this a crossover issue or something else? Does it matter what type of sub connection your using? I'm using analog line level.

Thanks again for your helpful input.

Hi Guys,

I ended up purchasing a DD-18. The mighty SVS is up for sale.

I haven't listened to the sub yet as I have spent the last 2 hours tweaking placement and settings.

A few questions for starters:

1. My processor has a Subwoofer XLR output. Is there any advantage to using this over the standard RCA output if I DON'T hear any noise or hum w/ my current setup? I would need to buy an XLR cable if I switched.

2. I noticed this right of the bat. In the manual all of the screen shots show a graph that goes from 0 DB to 100 DB. However, when actually using the software mine only goes from 0 to 87DB. Am I missing something?

3. I ended up using my processors's crossover set at 80 and the DD-18 set to 199. The processor does have the option to send a full range subwoofer signal. I own a Parasound C2 and they put a lot of work into making the crossover phase and time correct. Any reason I should switch and use the 18's crossover?

Thanks! I'll post my listening impressions soon.

-Brian

Click the link below to view the "Equalized" response.

http://www.softwaretraining.net/eq.jpg

How does this look overall? Is there room for improvement or should I stick with it?

I am concerned that I will not be getting sufficient low end response as there is a sharp drop off at 25 and below. Obviously boosting the lowest frequencies would overtax the amp and sub.

I anxiously await feedback!

-Brian

Last question for tonight.......

The smaller the "Q" number the more frequencies that are affected, correct?

-Brian

Out of curiosity, what is the range of Q values that are offered?

Ran

Hi Brian,
We've been on and offline over the holidays, sorry for the delayed response.

In response to your questions:
1. THe XLR (or balanced) input doesn't really offer any benefit if your system is noise free as you say. All inputs are summed and go to the same A to D conversion circuit.

2. You're talking about the Y axis on the graphs, right? Sadly, this is an errata that we have since corrected. We changed the scale right before we shipped to calibrate the system and the manuals had already gone to press. The key, though is to get a flat graph +/- 3 dB (see my comments on your graph below.

3. The Parasound and DD crossovers do essentially the same thing, so there is no compelling reason to use the DD's. Regarding phase/time sync, any delay usually shows up at or around the crossover frequency as a dip, and you can use the phase settings on the setting screen to compensate.



Yes, the smaller the Q number, the lower the "Quality" of the filter, and the more frequencies that are affected up and down from the primary frequency. A low Q is like a very wide wave and a high Q can be like a needlepoint.


Hi Ran, sorry for not answering your earlier post sooner...

The Q ranges from .3 to 20.0, with a default of 4.3 (the default width for third-octave centers, which is how the EQs start off). The contour filter (one for each preset - set on the settings page), actually acts as a 9th EQ, and its Q is fixed at 4.3.

Graph comments next...

Bruce

The graph looks very good overall, about +/- 2 dB above 30Hz. I would agree with you about the low end and would look to boost it up a bit. A few thoughts...

1. Don't be afraid to put an EQ or two down there. There is LOTS of headroom in the amp (1250 Wats RMS and 3000 watts peak - about the most you can get off a 117V line), and the DD-18 is the most efficient of all the DD subs, so it uses its power very effectively. Even if you "stack" EQs, the gain compression algorithms will kick in and protect from clipping or other unusual behavior if the headroom limit is reached, so the worst that happens is that is doesn't get any louder. However, I must say that this is a complaint we've yet to get with the DD-18.

2. You could raise the overall woofer system volume to see if it brings up the low end then tone down the rest of the graph to match the sats.

3. Is moving the woofer an option? There might be a suckout (cancellation) down there that no amount if EQ can fix, and if so you would be pouring power into a black hole.

4. You can play with the subsonic filter slope. It defaults to 24, a more gradual slope (like 6 or 12) might help.

5. Does you room connect to a larger area? We had a user in the UK who had a similar suckout at the low end. He thought his DD-15 was defective. He then realized that he was on the second floor and attempting to load his ENTIRE 3-story structure with the sub. He stacked 2 or three EQs down there and it worked - his comment was that the DD-15 was making his pipes rattle similar to a large truck or steamroller driving by - he had never heard that before.

So the moral is that is you are trying to load a large area, or a room that connects to another room, you may need to load up the power down there by stacking some EQs to load the space properly.

We get the comment a lot that one very nice thing about DD is that you can see the effect of these changes in real time to see what's working and what isn't.

Hope this helps,
Bruce

I'm setting up my first HT and chose the Velodyne SPL1000 Series II as my subwoofer. However, my lack of knowledge has me confused as to how it should be hooked up.
Blue Jean Cables sells single sub-woofer cables that have one connection on each end, does this mean that I have to buy two cables? My sub has both right and left RCA jacks (red & white).

Adding to my confusion is that my reciever (Yamaha RX-V2400) only has one sub-woofer output, so if the sub requires two rca jacks and the reciever only has one output, what do I do?

Thanks Bruce!

I will definately try your suggestions this evening.

-Brian

Hi Carl,
You only need one cable. The sub is mono in that it only plays one signal - you can get away with this with low bass since low frequencies are non-directional - that is you don't need them in a stereo pair since you can't tell where low frequencies are coming from. You plug the cable into the LFE jack on your Yamaha and into either the left or right jack on the back of the sub (I think the left input is labeled LFE, but it really doesn't matter). The sub "sums" together the L + R input.

Hope this helps,
Bruce

Bruce,

Thanks for the reply, but I'm not quite clear on the Q value for the sub. I was referring to the overall system Q of the DD-10 sub. If this is confidential info, I understand.

thanks,

Ran

Thanks Bruce, that makes sense. I still don't understand why they would put left and right jacks on the sub if we only need the LFE, but I guess I don't have to understand.

Thanks again for the help.

In a 2 channel system you would hook up both left and right low level analog inputs to the sub.

Hi Carl,
The two jacks do serve a purpose, but these days with LFE procesing in most receivers they are not used much. 2 channel system preamps/receivers often have a pre-out/pre-in L/R signal loop. Out of the box these usually have jumpers to connect them. They are used to run the full L/R signal to the sub, and then there are output L/R jacks on the sub that provide high pass crossover signal back to the pre-amp. This acts like the LFE processing - strips out the low frequencies for the sub to play and sends the high frequencies back to the preamp/amp for the mains to play.

Hope this helps,
Bruce

Sorry Ran, you're right - I didn't understand the question.

The unamplified Q of DD subs is about .7. However, depending on the model (shown in the upper right corner of the cover screen) we actually tell the software the mass of the cone, the spring constant of the suspension and other constants so that the software processing is able to compensate for these factors, effectively removing the Q element from the overall system.

Does that help?

Bruce

Bruce,

Thanks for the reply. That's some darned interesting software for sure. Yeah, I figured around .7, but I'm sure the tricks y'all play with the software can make it appear a little tighter or looser. Haven't heard one of the new babies yet, but I look forward to doing so and comparing it to a few other tiny tots.

thanks again,

Randy

That user was me

As Bruce says, I was having real problems setting up my DD-15 correctly but thanks to some outstanding after sales service from the UK distributor and the main UK Velodyne retailer, we realised that indeed my DD-15 was attempting to load 3 large, open plan floors!

This problem was overcome by a combination of closing doors in the upper and lower stories and stacking three of the DD-15's parametric EQs at the lower end of the frequency range.

After just one hour's work we managed to get a +/- 2 dB curve all the way down to 15Hz... with very usable ouput down to a staggering 12Hz. As Bruce mentioned above, the levels the DD-15 gets down to was having the same effect as a steamroller that was re-surfacing the main road outside my house - causing chaos with underfloor central hearing pipes.

I've since lifted the floorboards and lagged the pipes to avoid them making noise and the performance from the DD-15 is simply astonishing. I can see why Home Theatre Hi Fi.com made the DD Series it's Subwoofer product of the year for 2003.

Everytime I use the DD-15 with DVD material it impresses the hell out of me. I watched Bad Boys II last Saturday night and sat there with a huge grin plastered all over my face... the low end bass is so crystal clear that it just knocks you, physically, for six whilst underpinning the rest of the speakers to perfection.

Even using three EQs stacked in the same area the sub has masses of headroom to spare, more than I'd ever come close to using to be honest. I currently run the DD-15 at just 17 on it's volume scale and at -2 dB from my processor. Yes, it's that scary

I can't praise the DD-15 highly enough. An awesome, World beating product and no mistake.

I might be able to get a HGS-10 for about a grand. Is this a good deal? Will this be able to fill up a 17x13 room with nice clean bass for music and movies? The room is more or less open on the right side and half open in the back where the stairs lead to the second floor. It will be used for about 60% music and 40% movies. I am using a Yamaha 320 sub now and it is just not tight enough for me as far as music goes. It does somewhat OK on movies though.

Thanks,

PAT

Pat,

If you're a condo/apartment dweller and not trying to raise the roof, the HGS-10(version II, of course) is a sweet little sub. If you live in a house(and can crank it a little), I'd opt for an HGS-12. It totally depends upon your listening habits.


Ran

Hi Pat,
The HGS-10 was designed for small rooms. The openings you're referring to, make your room size very large and a 15" or 18" sub would be recommended. The HGS-10 would be working much to hard and limited in it's ability to energize the total displacement.
Curt

Thanks Curt & Ran. I listened to the HGS-10 tonight and although it was very good, especially for music, I agree it might be too small for my room. I do live in a house and my Yamaha is only a 10" sub and that does fill the room but it is just not as clean as I would like.

Thanks again,

PAT

Pat,

You're more than welcome. I know that the HGS-10 is very tight sounding, but I'm a little surprised that it didn't fill the room as well as the Yammy?...hmm. I'm guessing that the Yammy is either in a significantly larger enclosure, has a much higher Q value(assuming it's sealed), or both.
Yeah, if you're in a house, I'd step up to a larger sub than the HGS-10.

Good Luck,

Ran

JuBoy,

With regards to the 3 EQs you mentioned, what are they set at? +6 DB? I have to crank my subwoofer volume up to 45 in order to get a decent low end response.

-Brian

Brian,

Two of them are set at +6 dB and the third is set at +5 dB. This has given me a previously impossible to achieve +/- 2 dB curve from 20Hz down to the 15Hz lower limit that the DD on-screen graphic displays. It's quite obvious from this that useable output carries on way below 15Hz.

I have watched several DVDs with very low frequency effects at a few notches under reference level yet the DD-15 still seems to have masses of headroom left to spare.

If my DD-15 was a car it would certainly never have been out of 2nd gear and yet it still scares the living daylights out of me on occasion.

There was a scene in a recent episode of a well known UK TV soap show (Eastenders) where the actors were in the market square with a record store playing music in the background... I only knew that because the table I was resting my feet on started to move to the bass beat, I could only then start to hear the actual music very quietly in the background.

I also use my DD-15 placed on an Auralex Gramma isolation platform to avoid the sub imparting it's energy through my floorboards, which has the added benefit of making the bass much cleaner and ensuring the sub is impossible to localise.

A major benefit of the DD-15 hear has been that it's allowed me to 'visualise' what's actually been happening in my home cinema. Had I not been able to see the problem and deal with it, I could have gone on 'upgrading' to more and more expensive subwoofers and probably never got to the point I have now, which is as near perfect as a domestic (non-anechoic) room can realistically be. In that respect, the DD-15 has actually been a money saver, despite it's seemingly high purchase price.

Lets quit the bashing and keep to the topic please.

Bash post removed.

Thanks for this thread.

All I can say is that I have been extremely pleased with my HGS12 that I bought in 1999. In fact, it got me into a little trouble with my new neighbor at about 11 pm shortly after I moved into the new house. I was watching The Matrix and didn't realize that my neighbor could hear it in her bedroom in the house next door! Needless to say, it isn;t the best way to be introduced to your new neighbors. This sub rocks and I can only imagine what the DD series can do to worsen neighbor relations.

I always had a little hum when there was no signal going to it, but I remedied it by using car audio RCA Monster Cables that had a grounding wire running through it and used it to connect the outer RCA elements between the receiver (Yamaha RX-V795) and the HGS12, then the hum went away completely. It might have been possible that a ground loop or something existed between the two units.

I recently moved and had the new house prewired for 5.1. The subcontractor used RG-6 for the long cable run from the front of the room toward the back where the sub is now located. I simply purchased RCA to F connectors and used a splitter to send signal into both inputs on the sub. I don't know why, but I have not had the humming problem with the HGS12 with this set up. I don't care though, as long as it works without the hum.

Needless to say, I'm trying to be judicial in the volume control. especially at night, because I haven't been properly introduced to my new neighbors and I don't want to start out on the wrong foot again.

I've known distortion levels on some subwoofers to run to 40 and 50%. Distortion levels of 30% are quite common.
The Harmonics introduced by this high distortion is actually output that can be measured by a simple SPL meter. Therefore, while we could perceive that something may have the ability to fill a room, if much of this output is distortion, the listener is actually hearing muddied low frequencies and very little of the original signal. What is needed for accurate tight clean pure bass is something that offers very little distortion.

In my humble opinion, this is where Velodyne have always excelled.
As Curt mentioned above. All that is needed is the correct choice in size in order to energize the room well