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Discussion Starter · #1 ·
I recently bought a Behringer FDQ2496, but I think I bought the wrong thing. What I thought I was buying was an equalizer to smooth out bass peaks and dips in my subwoofer, but now I'm not sure what it does. Apparently its called the Feedback Destroyer Pro.


I thought I read an article which recommended this unit. However, after some further reading, I wonder if I read about the Behringer DEQ2496 or even some other Behringer unit with 2496 in the name, which I've since learned stands for 24 bits/96 kHz, I think.


Hoping that someone has the patience, I'll start at the beginning. Years ago I bought 3 NHT 1.1 speakers to use as mains and center with a Pro Logic system, along with 2 NHT Zeros for rear surrounds and a NHT SW2 subwoofer. All was fine except for the subwoofer, which had drastic peaks and valleys at various frequencies between 25 and 80 Hz. So I put it in the closet and watched HT and listed to music with very little bass.


Then we moved to a new house. So I bought a new 7.1 receiver (Yahama RX-V863) and tried out the sub again. Same results, if not worse. Then I started reading this forum and learned of such things as room modes, etc., but no matter where I place the subwoofer, the results are not good. Measurements (best placement so far) with a Radio Shack meter and test CD are:


(RS meter corrected, crossover set at 90 Hz on Sub, 90 Hz on receiver)


1000Hz 70 dB

200Hz 70dB

160Hz 70dB

125Hz 75 dB

100Hz 70 dB

80Hz 70 dB

63Hz 82 dB

50Hz 73 dB

40Hz 74 dB

31.5Hz 82 dB

25Hz 70 dB

20Hz 62dB


Now I've learned that perhaps what would help most is a second subwoofer, and that the Behringer is not very accurate below 100 Hz anyway. My room is basically 15.75' x 17.25', but with an additional 29" x 85" nook off of one corner, and 9 ft ceilings. I would think it would be fairly dead acoustically because it has 6' high bookshelves filled with books almost wall to wall, except where the two windows are, heavy carpet, sofa, two chairs, plus dozens of cardboard boxes stacked everywhere not yet unpacked from our move.


Finally, I realize that even if could find a matching sub on Ebay, there are much, much better subs on the market which are fairly reasonably priced. One that caught my eye is the Rythmik 12" F12 SE, but I'd welcome any suggestions. But, if I need two subs, then the price isn't quite so reasonable anymore.


Thanks to anyone who has waded through all this, and any info, thoughts, suggestions are very welcome. I really don't want to become frustrated to the point I give up. Thanks!


- Henry
 

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I don't find any such Behringer product called a FDQ2496. But the DEQ2496 is what you want. The FBQ line are stereo graphic equalizers. This provides fixed bands and fixed Qs. The DEQ is a parametric equalizer and provides definable bands and Qs. Other than some peaks at 31.5 and 63 hertz, this doesn't look bad. With the peaks at those two frequencies, it shows you have a room induced peak. Moving the sub will probably change this. The dip at 20Hz is probably due to the low end limits of the sub.
 

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Quote:
Originally Posted by ransac /forum/post/17017265


I don't find any such Behringer product called a FDQ2496. But the DEQ2496 is what you want. The FBQ line are stereo graphic equalizers. This provides fixed bands and fixed Qs. The DEQ is a parametric equalizer and provides definable bands and Qs. Other than some peaks at 31.5 and 63 hertz, this doesn't look bad. With the peaks at those two frequencies, it shows you have a room induced peak. The dip at 20Hz is probably due to the low end limits of the sub.

Actually, the FBQ2496 can be used as a parametric EQ. I'm using one myself and the FBQ2496 gives control of definable bands and Q's. However, the DEQ2496 does grant more EQ options (graphic and parametric), digital delay, and other features that the FBQ2496 does not.
 

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Discussion Starter · #5 ·
Thanks guys. Sorry about the typo. Behringer FBQ2496 is what I bought.


I'm glad my numbers don't look too bad, but this sub doesn't sound good to me. BTW, I'm sure the 20 Hz figure is normal roll off - that doesn't bother me at all - but the resonance at 31.5 Hz and multiples is irritating, and I'm sure it's room induced.


So I guess my question is, is there anyway to know (other than trial and error) whether dual subs would likely solve this problem, or would I be better off exchanging the Behringer for a DEQ2496?
 

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Quote:
Originally Posted by lalakersfan34 /forum/post/17017381


Actually, the FBQ2496 can be used as a parametric EQ. I'm using one myself and the FBQ2496 gives control of definable bands and Q's. However, the DEQ2496 does grant more EQ options (graphic and parametric), digital delay, and other features that the FBQ2496 does not.

I see where I went wrong. I used the OPs FDQ2496 model to search. Then I went the Behringer directly and looked under Equalizers. There it has the DEQ2496 with a couple FBQ models. But the FBQ models say they are stereo graphic equalizers. I searched again using FBQ2496 and see what you are talking about.
 

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Discussion Starter · #8 ·

Quote:
Originally Posted by lalakersfan34 /forum/post/17017381


Actually, the FBQ2496 can be used as a parametric EQ. I'm using one myself and the FBQ2496 gives control of definable bands and Q's. However, the DEQ2496 does grant more EQ options (graphic and parametric), digital delay, and other features that the FBQ2496 does not.

That's interesting. Does that mean I could use it to suppress the peaks at 31.5 Hz, 63 Hz, and 125 Hz for example, without disturbing the response at other frequencies? Can it adjust two subs independently if I ever needed to do that in the future?


- Harry
 

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Quote:
Originally Posted by HenryPercy /forum/post/17017445


That's interesting. Does that mean I could use it to suppress the peaks at 31.5 Hz, 63 Hz, and 125 Hz for example, without disturbing the response at other frequencies? Can it adjust two subs independently if I ever needed to do that in the future?


- Harry

Somewhat. It depends on the Q (width) as well as the extend of the boost or cut. You can't cut a single exact frequency without having any effect on the surrounding frequencies. Still, if you're careful you should be able to attack your three individual peaks without without disturbing other frequencies too much. Using a program like Room EQ Wizard (REW) can really help you see the effects your EQ filters have on your overall frequency response. I highly recommend it.
 

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Discussion Starter · #11 ·

Quote:
Originally Posted by lalakersfan34 /forum/post/17017789


Somewhat. It depends on the Q (width) as well as the extend of the boost or cut. You can't cut a single exact frequency without having any effect on the surrounding frequencies. Still, if you're careful you should be able to attack your three individual peaks without without disturbing other frequencies too much. Using a program like Room EQ Wizard (REW) can really help you see the effects your EQ filters have on your overall frequency response. I highly recommend it.

Sounds great. I'll find REW and give it a try. Thanks for the help.
 

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REW is great. So is bass eq. But just as important, and prehaps the better first step, is to look at layout...for smooth response:


1) get sub out of corner

2) get listening position away from walls

3) treat with bass traps


The first 2 will compromise smoothness for output. #3 will actually make both better.


So, I read that you tried a bunch of locations, but you haven't told us where, or a layout of the room...
 

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Discussion Starter · #15 ·

Quote:
Originally Posted by glaufman /forum/post/17019473


REW is great. So is bass eq. But just as important, and prehaps the better first step, is to look at layout...for smooth response:


1) get sub out of corner

2) get listening position away from walls

3) treat with bass traps


The first 2 will compromise smoothness for output. #3 will actually make both better.


So, I read that you tried a bunch of locations, but you haven't told us where, or a layout of the room...

I'll try to draw a sketch of the room and post it later. It would be hard to describe verbally.
 
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