Am I just asking for trouble?

My video processor has neat things like notch filters, adjustable crossovers, slopes, etc. that I found make significant improvements to the bass response from my subwoofers.

I would like similar control for my 2 channel set-up (which is single ended and solid state and NOT bi-wired) but am fearful of compromising the rest of the signal. Correction capabilities for the main speakers are a secondary consideration. Wife influences make make electronic correction the only viable option. I've read as many posts as I can on the matter, but am still lost-as usual. Am I just asking for trouble?

Any recommendations/help would be greatly appreciated. Budget would be $1000, but I would be willing to go higher (or lower) if warranted.
Most bass peaks "below" 70 or 80hz can not be tamed very effectively by a tube trap style Bass trap. The trap would have to be very large in diameter, and most of them are broad band in absorption any way. Bass peaks are relative narrow in width, and can't even be measured very accurately with 1/3 octave test tones. You will need a 1/6 or greater octave test tone for a more accurate picture. I think you need at least a 16 inch diameter Bass trap to reel in a 80hz peak. Below that frequency, the trap must be even larger. You can also build a Helmholtz Resonater for those lower freq's, but per your post, wife must be kept happy, and that should not be hard to do. Once you have done the best you can with speaker and sub placement in the room, this leaves EQ'ing.

If you are looking for something for your subs, try locating a Behringer DSP8024 Ultra Curve Pro. One just sold here for $150 used, and I paid $225 for mine new from Muscians Friend

l@@k here

This is a 2 channel parametric EQ that gives you control over Frequency, Bandwith, and Attenuation. It also allows you to control 3 axis, so you can tame room resonates for your rooms Length, Width, and Ceiling Height or any 3 seperate peaks that should occur in your room.

If you plug a mic into it, it will also function as a RTA, which is always nice to have around. There are many more nice features to numerous to mention.

The DSP8024 may have been discontinued, and replaced by the DEQ2496 @ $399 still well within your budget. Only down side is it is XLR based, so you will need a few XLR to RCA adapters. Mic for RTA is also extra.

Don't let the low price of the Behringer Pdts fool you, Musician Friends are pretty deep discounters....L@@Ks like this could be your hot ticket....


HTH, Dave

Here is some info on the DEQ2496

Ultra-high-precision 24-bit/96kHz EQ and RTA.

Ideal for audiophile mastering and PA purposes, it offers 4 concurrently selectable EQ modules: 31-band graphic, 10-band parametric, Feedback Destroyer, and 3 dynamic EQs per channel. Other highlights are the 61-band RTA that can run simultaneously with the EQ section, high-quality 24-bit/96kHz A/D/A converters, and 2 high-performance 32/40-bit floating-point SHARC digital signal processors which yield ultimate sonic resolution and 113dB dynamic range. Multifunction level meters, 64 user memories, RTA mic/line input with phantom power, word clock input, and MIDI connections. Balanced inputs, servo-balanced outputs with gold-plated XLR connectors, stereo aux output, and AES/EBU and S/PDIF I/Os (XLR and optical).


* Ultra high-resolution processor for all EQ, RTA, and dynamic applications
* 4 concurrently selectable EQ modules (31-band graphic, 10-band parametric, Feedback Destroyer, plus 3 dynamic EQs per stereo channel)
* Flexible compressor/expander function with peak limiter per stereo channel plus stereo imager and stereo delay for delay line applications
* Unique VPG (virtual paragraphic EQ) allows parametric control of graphic EQs
* Ultra high-resolution 61-band realtime FFT analyzer with additional auto EQ function for room and loudspeaker equalization
* Multifunction level meters (peak/RMS, VU, and SPL meter with dBA/dBC weighting via RTA mic input)
* 64 user memories for complete setups and/or individual module configurations
* Separate RTA mic/line input with phantom power, professional word clock input, and MIDI connections
* Ultra high-quality AKM® 24-bit/96kHz A/D/A converters (113dB dynamic range)
* Open architecture allowing future software updates via MIDI
* 2 high-performance 32/40-bit floating-point SHARC® digital signal processors for ultimate sonic resolution
* Balanced inputs and servo-balanced outputs with gold-plated XLR connectors, stereo aux output, AES/EBU and S/PDIF I/Os (XLR and optical)
* Internal switch-mode power supply for maximum flexibility, noise-free audio, superior transient response, and lowest possible power consumpti

How is something like that hooked up? Between the pre and power amp? Between the CD player and preamp? Thanks.

You would hook it up between your preamp, and your amp, but then you would be EQ'ing your main speakers. I did not think you wanted to do that. You may lose some resolution to the main speakers.

I was under the impression that you wanted to EQ your sub(s), and not the main speakers. Do you have a second preamp out, not a tape out, but a second preamp out, on your preamp??? If so, take the second preamp out, and run it to the Behringer, then run the Behringer to the sub(s). This way the Behringer is not in the circuit with the main speakers.

Generally, it is the floor to ceiling bounce (peak) that is most likely causing the worse problem. Also the first harmonic of that floor to ceiling bounce will be the next bite on the A$$.

If you have a 8 foot ceiling, the peak will be about 75hz and, it's first harmonic will be at 150hz.

Also, your other room dimension, especially if the room is smallish, can cause a stacking or reinforcing of the peaks. Now I'm getting ahead of myself a bit.

Post your room's dimensions, and lets see what we can see.

Here is a very simple example lets say you have a good size room, 31ft long, 17ft wide, and 8ft high. Our main concern would be with the 8ft dimension.

So lets say we have a 6db peak at 75hz. You would set the unit's FREQUENCY at 75hz (that's the frequency you want to reduce), then set the ATTENUATION at -6db(the amount you want to reduce the peak by), and set the BANDWITH at 3hz (the amount of width you want to treat on both sides of 75hz peak) the 3hz BANDWITH would be + or - 1 and 1/2hz on each side of 75hz. So you would get a 6db reduction from 73.5hz to 76.5hz. See, that's a pretty narrow range, and you will not be effecting the frequency on both sides of 75hz that don't need EQ'ing.

This is a very simplified example and there are more things that can come into play.

I feel that most people blame their subs for being slow or muddy, when it is the floor to ceiling peak that is causing the overhang and the slowness.

My questions to you are (1) do you have a second preamp out on your preamp (2) are you using a subwoofer, and (3) what are your room dimensions???

If you are not using a sub, you may have to consider using the PARC that Rives offers. It's more transparent and designed to work better with your main speaker and not give up any resolution. Using the PARC vs the Behringer for a sub may be a little overkill.

Only problem is, if you have to go for the PARC, it may cost you your next born male. You'll have to work that out with your wife.

If you want to contact me off site that's fine.


Yes, I have a second set of preouts on my preamp (Placette passive)-sorry for the lack of info. I also run a pair of subs (Velodyne HGS-10), but sometimes think that adds to the problem. The room is literally 60'x 20'x8' and the gear is at one end of the long side. My seating position, however is only 17' (if that matters). I appreciate your input.

You are in good a pair of IC's from second preamp pre-out to Behringer input, then run Behringer output to stereo subs. Now main speakers are not being EQ'ed and will maintain all their transparency and resoultion. You will only be EQ'ing the subs, thats what you want to do.

Behringer unit will work fine, no need for PARC or giving up next born male.

Room is good size... I will work the numbers, and get back to you in the morning.

All of a sudden my computer is crashing... I will stay in touch somehow...sit tight I'm in CT and on EST.

I've had a chance to run the numbers, here is what I found...

Low bass reinforcement @ 28.2hz

Mid bass reinforcement @ 56.4hz
@70 to 75hz

Upper bass reinforcement @ 112/113hz
@ 141/141.12/141.22hz

This has nothing to do with your subs,speakers,speaker type (vented or sealed)or speaker placement. This is do to the rooms natural reactions to it's dimensions

The largest peaks will probably be in the 70to 84hz range and the 141hz region

There are 3 ways to check for peaks... (1) Mathematically like i've done (2) use a test disc, and a SPL meter to measure (3) run the Bass decades on the Test disc, and listen for all Hell to break loose in the room. You will definately hear the difference between a clean bass frequency, and when the bass frequency hits the room's resonate points. Recessed lighting,floor lamps, pictures on walls, and items on table tops will vibrate in sympathy.

Looks like your a candidate for some EQ'ing. No dought the bass problem you are hearing is a problem. Also if we continue up the frequency range, I'm sure that the higher bass harmonics will also be reducing clarity in the Mid-range. OUCH!!!!!!!

Email me off site at... this is not the email I have listed here at A/gon (which is gives me unlimited composing time (i'm very slow ) and spell check( my spelling SUXS)