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Salerno Subwoofer: SI HT18D4 11Hz LLT... times TWO! - Page 2

post #31 of 61
What settings are you running with the LR and subs? What is the crossover? Run the sweeps in stereo mode, speakers set to small, xo will depend upon your measurements. Try the 80hz setting at first and see what the area looks like. Then use your delay settings for your sub to fix any probelms. I had a huge dip at 80hz running all my speakers at the same distance(delay) and they are all 14 feet away. My magic number was setting my subs to 7 feet 6 inches and now my crossover area was smooth and even. No phase changes needed. The 30 hz dip looks to be a room issue, try moving the seat back a little if you can(or forward). The easier way would be to place your mic a little farther and see what happens.
post #32 of 61
that 70hz suckout is really messing things up. without that, the fr wouldn't look too bad.

70hz places 1/4 reflective cancellation almost right on 4 feet. are your mains 4 feet from the side walls, floor/ceiling, and rear wall?

if you could move the mains and run the mains only sweep again just to see if that cancellation is reflection-based or something else.

is there anything in the room, like a wall or a door that vibrates like crazy at 70hz, which could be sucking all the energy out of that frequency?
post #33 of 61
" No phase changes needed."

mk, changing the distance settings has the same effect as changing the phase with delay.
post #34 of 61
Yes but I have always had better results using the delay than phase for some reason over the whole response. Probably just lucky.
post #35 of 61
Thread Starter 
Quote:
Originally Posted by MKtheater View Post

What settings are you running with the LR and subs? What is the crossover? Run the sweeps in stereo mode, speakers set to small, xo will depend upon your measurements. Try the 80hz setting at first and see what the area looks like. Then use your delay settings for your sub to fix any probelms. I had a huge dip at 80hz running all my speakers at the same distance(delay) and they are all 14 feet away. My magic number was setting my subs to 7 feet 6 inches and now my crossover area was smooth and even. No phase changes needed. The 30 hz dip looks to be a room issue, try moving the seat back a little if you can(or forward). The easier way would be to place your mic a little farther and see what happens.

The sweep was done with a 40Hz XO with the receiver in stereo mode. I had previously done sweeps with the XO at 40, 50, 60, 70, and 80Hz and found 60Hz to be best, but after running Audyssey, 40Hz looks better. However, since I only have one sub built at this point, I'm not too concerned about addressing issues since the addition of the 2nd will likely change things, and may solve or at least reduce some problems.

My speakers are about 1' from the front and side walls. Not ideal, I know, but I'm pretty limited since I have doors in the front of the room, and moving them away from the side wall would put them in front of the screen. (see room picture in picture section). I have a feeling that bass trapping is in my future, which is no big deal since the German hardware stores carry mineral wool.
post #36 of 61
Quote:
Originally Posted by LTD02 View Post

that 70hz suckout is really messing things up. without that, the fr wouldn't look too bad.

70hz places 1/4 reflective cancellation almost right on 4 feet. are your mains 4 feet from the side walls, floor/ceiling, and rear wall?

if you could move the mains and run the mains only sweep again just to see if that cancellation is reflection-based or something else.

is there anything in the room, like a wall or a door that vibrates like crazy at 70hz, which could be sucking all the energy out of that frequency?

I have several newbe questions with regards to this post of yours LTD02.

First, what is the formula for figuring the 1/4" wave cancellation that you described above?

Also, how do you tell if something is reflection based or whatever like you also described above? Is the best way to tell about reflections with a waterfall graph?
post #37 of 61
Thread Starter 
Well, I got my iNuke3000DSP, and have been playing with it with little success...

I inputted a -12db HP Filter at 20Hz along with a -12db HS filter at 20Hz. The thing is, when I run my receiver's test tones, I have to turn my LFE level up to +7 to get to 69db. (this takes into account a +6db gain from a second sub, for a total of 75db) The thing is, my LFE output will clip at -2 with a 0dbFS signal. And so I am limited to a maximum volume of -10db. This is with the gain on the iNuke set to 7 clicks below full volume (or rather, 7 clicks below zero attenuation of the input signal). I have to have it set that low because any higher and the input will clip with a 0dbFS signal.

I tried doing a -6db HP and -6db HS, but I was going beyond XMAX a bit before getting the volume turned all the way up.

I am theorizing that I should get more output if I hook my driver up in parallel, which would be a 2 ohm load, as opposed to my current 8 ohm load by hooking up the coils in series. Hopefully that will make up for the -12db negative gain of the high shelf filter. Am I correct in this assumption?

The other option would be to get an external processor which can give me a 10Hz HP filter so that I don't have to attenuate the input. If I have to go that route, what are my options? MiniDSP with a plugin that allows for a 10Hz HP?
post #38 of 61
You can boost input gain by 12 db in the amp itself.

Edit. I missed the part where you are saying that input signal was clipping already.

Can you post screen shots of the DSP ?
Edited by zheka - 3/19/13 at 5:01pm
post #39 of 61
Thread Starter 
Quote:
Originally Posted by zheka View Post

You can boost input gain by 12 db in the amp itself.

Edit. I missed the part where you are saying that input signal was clipping already.

Can you post screen shots of the DSP ?

Ah, OK, looking at it again, I think I was using that gain incorrectly. I was thinking it was gain of the HP filter. Now it makes more sense.

I'll be playing with it more tonight. Adjusting that gain up should hopefully fix my issue. Another idea I had was to set a low shelf filter with a gain of 12db at 200Hz or more. That would cancel out the negative gain of the high shelf, while leaving in place the virtual 10Hz HP which is the sum of the 20Hz HP/HS filter. However, I'm worried that I might have to set a more agressive HP if I want to play down to 11Hz at reference, and still be safe from <11Hz peaks. I wish there was some software were I could play around with the HS/HP and see the sum.

What I ultimately hope to accomplish is a state where I have both the input knobs adjusted to max, and still be able to have my full range from my receiver. I want to do this in order to be at a point where if my two very young boys one day decide to start turning those knobs, I won't end up with a couple blown drivers when I start up a movie without verifying the positions of those knobs first...
post #40 of 61
Thread Starter 
Ok, I have things figured out a bit better now, and I'm closer to the goal. Where I'm at now, I achieved having my gain knob turned all the way up, and was able to achieve the proper level on a test tone using 8db of boost in the XO area. Right now my settings are:

12db HP @20Hz
-12db HS @ 20Hz
8db signal boost
Receiver LFE out setting of -12db

The only issue I have now is that I'm amp limited in that I can only get up to about -6db on the receiver before clipping the output. (this is taking into account an expected 6db of gain I'll get from a second sub) So theoretically, once I get both subs in, I'll only be able to play up to -6dbFS. And so I may have to experiment with wiring my coils in parallel to see if that gives me the extra output I need.

I'll post screen shots of my Behringer a little later once I have a little extra time.
post #41 of 61
Why build an 11hz tuned sub and HP at 20hz? You should not be clipping that amp as it should have enough power to driver both subs, not just one.
post #42 of 61
Quote:
Originally Posted by DanLW View Post

Ok, I have things figured out a bit better now, and I'm closer to the goal. Where I'm at now, I achieved having my gain knob turned all the way up, and was able to achieve the proper level on a test tone using 8db of boost in the XO area. Right now my settings are:

12db HP @20Hz
-12db HS @ 20Hz
8db signal boost
Receiver LFE out setting of -12db

The only issue I have now is that I'm amp limited in that I can only get up to about -6db on the receiver before clipping the output. (this is taking into account an expected 6db of gain I'll get from a second sub) So theoretically, once I get both subs in, I'll only be able to play up to -6dbFS. And so I may have to experiment with wiring my coils in parallel to see if that gives me the extra output I need.

I'll post screen shots of my Behringer a little later once I have a little extra time.

i'll be running mine in 2 ohm config. I do not think the power Inuke can push into 8 ohm stereo is enough for these drivers.
post #43 of 61
Quote:
Originally Posted by MKtheater View Post

Why build an 11hz tuned sub and HP at 20hz? You should not be clipping that amp as it should have enough power to driver both subs, not just one.

he is doing the 10Hz HPF workaround LTD02 suggested
post #44 of 61
What size room again? Before I set a HP filter I would wire each sub as 8 ohms and then run them parallel to the bridged inuke amp so you have max power into 4 ohms and now just one channel of LFE(2 subs). Once you get it wired up like this then run compression sweeps and then you can see if a HP is even needed. If this is a large room then run one but a small room may not be needed. I have a 2100 cubic foot room and I ran 4 LLT's at 13.4hz and I never needed one.
post #45 of 61
"First, what is the formula for figuring the 1/4 wave cancellation that you described above?"

hi marty,

for practical purposes, the speed of sound is around 1130 feet per second.

in order to figure out how long a wavelength is for a given frequency, just divide the speed of sound by the frequency in hz.

for example: how long is the wavelength at 100hz? answer: 1130 (f/s) / 100 (1/s) = 11.3 feet.

question: if you are getting a 1/4 wave cancellation at 70hz, how far is that to a boundary?

answer: wavelength at 70hz is 1130 / 70 = 16.1 feet, so 1/4 of that is about 4 feet.
post #46 of 61
Thread Starter 
Quote:
Originally Posted by MKtheater View Post

What size room again? Before I set a HP filter I would wire each sub as 8 ohms and then run them parallel to the bridged inuke amp so you have max power into 4 ohms and now just one channel of LFE(2 subs). Once you get it wired up like this then run compression sweeps and then you can see if a HP is even needed. If this is a large room then run one but a small room may not be needed. I have a 2100 cubic foot room and I ran 4 LLT's at 13.4hz and I never needed one.

I determined my need for a 10Hz HP by feeding the worst case scenario into my amp. The short version is if a 0dbFS <10Hz signal is seen at the amp input, my driver will be pushed well beyond Xmax, and most certainly beyond Xmech also.

Long version:

To do the test, I downloaded the Audio Test DVD, which is available in a sticky post atop the DIY forum.
With my subwoofer's output level calibrated using my receiver's test tone output, I started with a receiver volume setting of -20db.
I then played the 1Hz - 20Hz -.5dbFS test tones, gradually increasing my amplifier's volume setting until XMax (23mm) was reached. I believe somewhere around -12db on the volume is when I started reaching Xmax, as indicated by my super ultra accurate test rig pictured below:



Therefore, if I were to turn my volume up to 0 and my subwoofer was presented with a 0dbFS peak below 10Hz, I would damage/destroy my driver. Therefore, I have added a 10Hz HP.

I could see if you were running 4 LLTs in a room my size, a highpass would not be needed... because you would not need to push the drivers nearly as hard as I do. Since I have just two, I have to push my drivers near the limit to play up to reference levels.

Sure, I could ditch the highpass, and lock my receiver's maximum volume somewhere between -10 and -5. But what fun would that be? biggrin.gif

Okay, it was requested, so here they are. Screen shots of my iNuke setup.

My amp is set in "Stereo" mode. I don't like the naming as it seems counter-intuitive. However, I have verified that in this mode, a mono input to channel A is indeed passed to both A and B outputs. So I can run two subs off one input. As an alternative, it looks like you could also run two subs using "Bi Amp" mode. The advantage of this mode is you can EQ each sub separately, and even insert a phase offset if desired.



The 20Hz 12db/octave high pass shown here is combined with the 10Hz 12db/octave high shelf with a -12db gain, as shown in the next picture.


The highpass and high shelf sum together and result in a "phantom" 10Hz high pass filter.


I have verified through excursion testing that this does indeed work in reality.
post #47 of 61
I understand except I don't think there exists a 0 dBFS signal below 10hz, everything at 10hz and lower is always much lower in amplitude therefore creating a natural high pass filter and your amp rolls off at 10 hz making for even a bigger slope. Usually the signal is not strong enough to matter, but protection is always nice in case. I ran my subs at 12 dBs Over reference without a problem or bad noises. Basically what I did was set the first sub to reference and then with each additional sub I just left the gain as is which resulted in max gain. To be safe I could have run the pair at reference and then with the additional pair be at 6 dBs over reference. I have 12 drivers now and run 10 dBs hot but they are sealed.
post #48 of 61
"I have verified through excursion testing that this does indeed work in reality."

that's great data and a really great post. nice work.
post #49 of 61
Quote:
Originally Posted by LTD02 View Post

that's great data and a really great post. nice work.

Seconded. Very clever measurement, Dan!
post #50 of 61
Thread Starter 
Didn't do too much tonight, but I did re-wire my subwoofer into a parallel configuration. So now I am running 2 ohms. I haven't done any sweeps yet to see if the iNuke can now give me that last extra bit in the infrasonic range, but I did do a pink noise measurement, and just changing from series to parallel netted me 10 extra db. And so I turned down the internal gain in the XO section to compensate.

One more picture of a design feature that came about in the middle of construction. This is a port in the side of the sub. Basically, I used a plunge router to rout down approx. 3/8 inches. I then cut out the center, so that there was a rectangular hole in the side wall with a 3/8" thick flange. I then took a piece of scrap MDF and made the access panel piece. There is gasketing tape sandwiched between the two pieces, along with T-Nuts backed by MDF strips so that they don't back out. This hatch makes it possible to re-wire the driver without having to remove the driver. It just takes a bit of feeling around.

post #51 of 61
What's the point of tuning to 10hz? With that low of a tune you're basically getting the same efficiency of a sealed alignment however with sealed, the enclosure volume would be significantly less.
Edited by mynym - 3/23/13 at 5:10pm
post #52 of 61
That is not true, you get much more spl at 10hz with the port. The sealed sub will have more spl in the single digits though, like 6-8 hz since this is tuned so low.
post #53 of 61
Thread Starter 
As an update, I've cut all the wood for the second sub. I'll be assembling it in the first week of April, and I hope to have it complete by the 6th. Also, I've been able to tweak with my amp and it looks like I'll be able to safely go to -3db on the receiver at reference level. Any higher, and I risk damaging a driver if a spike larger than -3dbFS comes through in the single digits, even with the 10Hz HP. Looks like I need to fire up Spectrum Lab sometime and see just how high those single digit peaks are.
Quote:
Originally Posted by mynym View Post

What's the point of tuning to 10hz? With that low of a tune you're basically getting the same efficiency of a sealed alignment however with sealed, the enclosure volume would be significantly less.

Two big reasons to go with an LLT alignment. First, THD is kept low to well below the audible range, whereas a sealed alignment's THD begins to increase dramatically even above 20Hz. Second, gobs and gobs of amplification are not required since it's easier to push the driver all the way down to tuning. So you save money in not having to buy larger amps, and not having to install dedicated high current lines to the amps.

The only real downside to LLT is the size and weight. For me, I'm using them as a 3rd row riser, so it all works out.
post #54 of 61
Thread Starter 
HUGE update! The second subwoofer is finished!

A detailed shot showing the system I used to keep the T-nuts in permanently.


The inside end of the access panel.


The bracing system for the second sub. This one should be more mechanically secure in that the vertical braces were cut so that they would go inbetween the horizontal braces.


A closer shot of the internal bracing.


The "Third Row Riser". Two Salerno Subwoofers nestled side by side.


These measurements were taken using a Radio Shack SPL meter as a microphone. No microphone calibration file was set in REW, per the advice of some in this forum. A sound card cal file was in place. The output of the meter was fed into the line input of the sound card integrated into my HTPC. (VIA VT1708S, which is the sound integrated onto my Asus P8B75-M LX Plus motherboard)

Amplifier Setup:

The below sweeps were taken with my subs powered by a Behringer iNuke 3000 DSP amplifier. Both drivers are Stereo Integrity HT18 D4 drivers, meaning they have dual 4 ohm coils. The coils are wired in parallel, resulting in a 2 ohm load seen by the iNuke. Also, I have replaced the stock fan in my iNuke with an 80mm Noctua 1800rpm fan. After installing the fan and turning on the amp, I thought I did something wrong because I didn't hear anything. But the fan was indeed on and moving air. Huge difference!

iNuke settings:
Configuration: Bi-Amp 1
Peak Limiter: -1.4dBfs Hold 200ms Release 200ms
Filter/Crossover (same settings for both channels)
Gain: 3db
High Pass 1 & 3: 20Hz, Butterworth, 12db/oct
Low Pass 2 & 4: OFF
PEQ (same settings for both channels):
Filter 1: -12db, 20Hz, High Shelf 12db/oct
Filter 2-8: Off at this time
Dynamic EQ: OFF

iNuke settings discussion:

Configuration: Bi-Amp 1

I had initially set the amplifier to "Stereo", thinking that both inputs were summed and sent to both outputs. However, this is not true. In this mode, Input A and B are indeed separate. However, the EQ settings are linked so that both channels have identical EQ settings. I found in Bi-Amp, the one input is indeed fed to both outputs. Normally this configuration would power a woofer and a tweeter. However, since I set the filters identically for both channels, both A and B outputs were identical. And so it would seem that "Bi-Amp 1" is the same as using a Y splitter to connect the LFE output to both inputs on the iNuke. Only I don't have to buy a splitter. Theoretically, "Bi-Amp 2" should work the same as "Bi-Amp 1" However, I haven't tested this.

Peak Limiter: -1.4dBfs Hold 200ms Release 200ms

Admittedly, I didn't realize I had this enabled. Looking at the measurements, it doesn't look like it affected anything. According to the iNuke software, this limit would kick in at roughly 1800W. When I do further sweeps tomorrow, I'll have to do some while watching my output levels to see if I am actually anywhere near the limits. I doubt I am, however. I'll have to play around with this one and see how it affects things.

Filters:

For those of you just joining us, I have created a "Phantom 10Hz High Pass filter" by combining a 20Hz 12db/oct High Pass filter and a -12db 12db/oct High Shelf filter. These filters sum to create the "Phantom" High Pass filter at 10Hz. As seen in the measurements below, this method indeed does work on the iNuke.

On to the measurements! All measurements are at the prime listening position unless otherwise noted.

Front row sweeps with just the subs, and with integration of the fronts. The higher level sweep is just the subs - sound card output fed directly to the iNike 3000.. The sweep which is lower in level is with the front speakers engaged - HDMI Stereo output to my receiver, with the fronts (Klipsch Rf-7 IIs) crossed over at 40Hz.. I didn't level match between going directly to the sub, and going through the receiver, so disregard the level difference and rather examine the room response. The measurements were taken from the front row left, center (prime) and right seats. This was done to see how positioning affected the response.


Looking at just the sweeps done with the fronts engaged, the frequency response actually looks pretty good, with the exception of the hole at 70Hz. However, notice in the above chart that with just the subwoofers, the 70Hz hole is not there. This tells me that it is not a room issue, and is rather the subs interacting negatively with the fronts. Or, it could be the fronts interacting with each other. I'll have to try measuring again with the subs off to see if this is an issue with the way the front speakers are interacting with each other.

Another thing I notice is that all the sweeps are very similar up to about 80Hz. Past that, the left seat is hearing less. This seat is right next to some 2" mineral wool panels, and is also pretty far off axis with the right speaker. I may have to experiment with toe-in to see if I can get that seat sounding better. However, this seat is the chase lounge seat, and therefore the wife seat. Maybe I should leave it as is so she will be less likely to ask me to turn it down?


Rear with and without fronts.


Rear row with the fronts. Immediately I notice that the hole at 70Hz is gone, and now we have holes at roughly 25 and 45Hz. Now, let's see what is shared between the two rows.


This sweep is the combined average of the front and rear rows. There's a nasty peak at 28Hz which is common to both the rows. This I should be able to tame with EQ. However, I'm going to experiment with some mineral wool panels I acquired today. They're 80mm thick, and just three of them are pretty darn heavy. I'll have pictures of the stuff tomorrow.


The lower sweeps are subs A and B individually. The highest sweep is both subs working together. All three sweeps were done with the sound card output fed directly to the iNuke input. The only thing I changed between the three sweeps was which subwoofer was plugged in. Other than that, the output level and microphone position were identical.


Effects of the "Phantom 10Hz HP filter". The filter was crated by combining a 20Hz -12db/oct HP filter and a -12db HS filter set at 20Hz. Both sweeps were done with the same output level from Room EQ Wizard. At the amplifier, however, the input gain was set to -9db. When the phantom 10Hz HP is in effect, I have the input gain set to +3db to compensate for the 12db of loss from the negative gain high shelf filter. When I remove that filter, I have to adjust my input gain to -9db to keep the same overall level.

We see at 30Hz, the sweeps are identical. At 20Hz, I'm down by about .5db. By 12Hz, I've lost 2db. By 8Hz, I've lost 3db, and by 6Hz I'm down by 4db. And so, while I am losing a little by using a high pass, I'm not losing much. I figure a few db is an acceptable trade for a little peace of mind that I can play up to reference without breaking anything.


Phase comparison. Setting either sub to 180 degrees out of phase completely trashes the LF response. I may experiment with some delay if treatments don't help fix some of my issues.


Two sweeps at -5 and -10dbFS. These were done with the sound card output connected directly to the iNuke 3000 input. Interestingly, the gaping hole from 30 to 55Hz isn't there when the fronts are in the mix.


This chart shows my room gain. The blue curve is a near field measurement taken from about 1 foot from the driver. The gold curve is at the listening position. Levels were adjusted between tests to compensate for the db loss associated with moving away from the subwoofer.

I'm not sure where exactly to line the two sweeps up since they don't resemble each other very much. But it looks like I'm getting anywhere from 13 to 20db of room gain by the time I'm at 10Hz.


These sweeps were generated by telling REW to divide the above LP curve by the NF curve. The resulting curves show a room gain of 13 to 20db at 10Hz. The higher curve was generated using the above curves as is. The lower curve was generated by offsetting the Near Field curve by approximately +7db to get it to more closely match the LP curve. According to my room dimensions, my room gain should be starting at about 30Hz. So my true curve is somewhere inbetween these two. So worst case, 13db of room gain at 10Hz, best case 20db.


Conclusions

First and foremost, LTD02's idea of summing a 20Hz HP and -12db HS filter indeed does work in practice. Kudos!

Second, the Behringer iNuke 3000DSP doesn't seem to have any trouble pushing gobs of power into two 2 ohm loads, even way down at 10Hz. From some excursion tests I've done, I am definitely not amp limited. The Behringer is enough to push me beyond XMax even above tuning. Your mileage may vary if you are pushing a high wattage driver in a sealed configuration, but as far as LLT goes, the iNuke 3000 is good to go!

The Way Ahead

Tomorrow, I will be doing more measurements with bass traps in place. Hopefully these will tame down some of my issues so that I won't have to do a lot of equalizing.
Edited by DanLW - 4/5/13 at 3:28pm
post #55 of 61
Thread Starter 
In the spirit of information overload, decay, waterfall, and spectrograms!

Front and rear center listening position. I notice that for the 70Hz hole in the front position, the sound seems to ramp up as time goes on. For the two holes in the rear listening posistion, the same seems to be true. Does this indicate cancellation?



Waterfalls, front on top, rear on bottom.



Spectrograms, front on top, rear on bottom.



I'm guessing my 28Hz problem is a room mode, perhaps? Not sure about the other problems. I'm hoping those of you who are more experienced at reading these can point out my issues and ways to tackle them.

Edit: Plugged my room dimensions (19' x 12' 6" x 7' 10") into a room mode calculator. Here's what I got up to 100Hz
Code:
Freq %       Wavelength, 1/2, 1/4    p,q,r Mode              Group Weighting
29.7 hz                 38'1", 19'0", 9'6"       (1,0,0 Axial)           
45.2 hz         34.2%   25'0", 12'6", 6'3"       (0,1,0 Axial)           
54.1 hz         16.4%   20'11", 10'5", 5'3"      (1,1,0 Tangential)              
59.5 hz         9%      18'12", 9'6", 4'9"       (2,0,0 Axial)           
72.2 hz         17.5%   15'8", 7'10", 3'11"      (0,0,1 Axial)           
74.7 hz         3.3%    15'2", 7'7", 3'9"        (2,1,0 Tangential)              
78.0 hz         4.2%    14'6", 7'3", 3'7"        (1,0,1 Tangential)              
85.1 hz         8.3%    13'3", 6'8", 3'4"        (0,1,1 Tangential)              
89.2 hz         4.5%    12'8", 6'4", 3'2"        (3,0,0 Axial)           
90.2 hz         1.1%    12'6", 6'3", 3'2"        (1,1,1 Oblique)         
90.4 hz         0.2%    12'6", 6'3", 3'2"        (0,2,0 Axial)           
93.5 hz         3.3%    12'1", 6'1", 3'0"        (2,0,1 Tangential)              
95.2 hz         1.7%    11'10", 5'11", 2'12"     (1,2,0 Tangential)

Looks like my bump at 29Hz is definitely a room mode. And the back row issue at 45Hz looks to be a modal issue. But I don't think the one at 70Hz is, especially since it doesn't exist when it's just the subwoofer generating the sweep.
Edited by DanLW - 4/5/13 at 4:01pm
post #56 of 61
How are you liking the extension and output of this Stereo Integrity 18D4? Are you just running one of them, or two? Sorry but I couldn't remember and didn't feel like reading everything again. LoL! '

Also, have you done any measurements to see what kind of actual, real world extension you are getting out of these bad boys?

With regards to the iNukes, If it were me, I would never use an iNuke on a sub due to the fact that it rolls off the frequency at 20hz, but in my opinion they would be absolutely great for powering the LCR's in a theater room.


Quick question about the iNukes and Crown XTI series of amps, can these amps be configured to run a 2-way speaker actively? (ie say that I wanted a stereo pair of active 2-ways, could I use two iNukes, one for each speaker, in an active configuration?)
post #57 of 61
Thread Starter 
Quote:
Originally Posted by Martycool007 View Post

How are you liking the extension and output of this Stereo Integrity 18D4? Are you just running one of them, or two? Sorry but I couldn't remember and didn't feel like reading everything again. LoL! '

I am running two HT18D4s, each in it's very own 22cu ft enclosure. Both of them combined make a lovely third row riser. As far as output, at -6db on the dial, I'm extending down to 9Hz at 110db. I have my receiver set to -3db as the maximum allowed volume, as excursion tests have show that I can't go higher than 113db without pushing the drivers past XMax in case of a single digit 0dbFS spike. I may play around with more aggressive dynamic EQ settings so that I can get to 115db, however.


Quote:
Also, have you done any measurements to see what kind of actual, real world extension you are getting out of these bad boys?

The charts I posted in posts #54 and 55 are what you are looking for. Those are all actual real world measurements. They are not simulations. They are in room frequency response graphs.
Quote:
With regards to the iNukes, If it were me, I would never use an iNuke on a sub due to the fact that it rolls off the frequency at 20hz, but in my opinion they would be absolutely great for powering the LCR's in a theater room.

In reality, they roll off much lower than 20Hz. Right now, I am excursion limited, not amp limited. And I am flat to 10Hz. Sure, the published spec is 20Hz. but the measurements I've done clearly show that the iNuke amps have absolutely no problem pushing high levels of output well below 20Hz. And I'm running each channel of the iNuke into a 2 ohm load. According some some things I've read, it should be running out of gas at that point. But lo and behold, 3% THD at 11Hz, 110db.



I did that one at my "higher" listening level of -5db. Since my tuning is 11Hz, I cold easily boost the level to find the max, but that would be unrealistic since if I moved away from tuning, I would be having over excursion issues. I have my amp's limiter set at -7dbFS, and I am not hitting it. And if I was clipping the output, my THD would have been much greater than 3%. Keep in mind, this is 11Hz per chanel, each into a 2 ohm load.

But that's one of the beautiful things about an LLT alignment. You don't need a boatload of power to achieve your desired output. If you were running a sealed alignment, the iNuke might give you grief. But for my application, the iNuke is delivering more than enough power well into single digits.
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Quick question about the iNukes and Crown XTI series of amps, can these amps be configured to run a 2-way speaker actively? (ie say that I wanted a stereo pair of active 2-ways, could I use two iNukes, one for each speaker, in an active configuration?)

Yes, the iNuke can run a 2-way speaker actively using "bi-amp" mode. In this mode, one input is fed into both output DSP chains. Each chain can then be set up to your liking. That is actually the mode I am using, only I am running two woofers, not a woofer and a tweeter.
post #58 of 61
Wow! i just learned several new things, the first being that the iNuke can seriously get down low when needed, regardless of what the published specs maybe.

The second thing that I just learned is that the iNuke can indeed act as an active crossover for 2-way speakers. I have a few questions now...

Is the iNuke very hard to setup as an amplified active crossover for a 2-way speaker?
& will a usb mic from Cross Spectrum Labs be enough to take measurements with my
laptop?

Second, I would assume that there is no way to run an active 3-way speaker off the iNukes, right?
I have a couple of builds going on right now, and plan on using my MiniDsp 10 x 10 to actively
crossover the 3-ways that I am building, then they will be powered by Behringer EP amps.

With all of that being said, I need to pick up a couple of the iNuke 1000DSP amps to use in
place of my EP4k's and EP1.5ki's.
post #59 of 61
Thread Starter 
Quote:
Originally Posted by Martycool007 View Post

Wow! i just learned several new things, the first being that the iNuke can seriously get down low when needed, regardless of what the published specs maybe.

The second thing that I just learned is that the iNuke can indeed act as an active crossover for 2-way speakers. I have a few questions now...

Is the iNuke very hard to setup as an amplified active crossover for a 2-way speaker?
& will a usb mic from Cross Spectrum Labs be enough to take measurements with my
laptop?

Second, I would assume that there is no way to run an active 3-way speaker off the iNukes, right?
I have a couple of builds going on right now, and plan on using my MiniDsp 10 x 10 to actively
crossover the 3-ways that I am building, then they will be powered by Behringer EP amps.

With all of that being said, I need to pick up a couple of the iNuke 1000DSP amps to use in
place of my EP4k's and EP1.5ki's.

I'd recommend downloading the iNuke Remote Connect software. You don't need to have an amplifier to be able to play with it. Here is the page for the amplifier:

http://www.behringer.com/EN/Products/NU3000DSP.aspx

Below the picture of the amp is a button labeled "Download the iNuke Remote Connect Software Here". Do that, and you'll have access to the software control panel for the iNuke. The only thing you can't do from this software control panel is adjust the gain knobs on the front of the amp itself.

With one, you can't do 3-way. However, with two, you could easily do 3 way, or even 4 way. With three iNukes, you could do two 3-way speakers. Simply use a Y splitter to feed your line level input to the two amps. One amp, we'll say Amp A, would be set up as "Bi-Amp", and the other (let's call it Amp B) as dual mono. Amp A would handle two of the three ways, and amp B would handle the third way. If you got a 3rd amp (Amp C), that could handle two ways of a second speaker, with the leftover output of amp B handling the third way. What's more, the A channel output of the iNukes is wired for a 4-pole Speakon connector, so if you wanted to, you could run one cable from the first amp, and one cable from the second amp to your speaker. That way you just need two cables instead of three.
post #60 of 61
I don't know why more guys don't do their bracing like you've done. Bill Fitzmaurice is proud of ya! Is the material MDF?
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