Dual sub-woofers??

[Sir Terrence the Terrible]

Doc,

(Or Terrible) If you were on a budget, would you get a few bass traps or EQ for the best bass response you could afford?

THOB

Dang bored hand, this is a tough one!! Doc may have a different answer than I have, but I always go acoustic before electric. So I would get the traps(because I know they help), and If I had anymore problems I would get the eq later. A good eq is not that expensive( I paid $125 buck for each of mine) and if the traps don't take care of all the acoustical problems, then an addition of a eq, along with the traps, probably can.

[the hand of boredom]

Dang bored hand, this is a tough one!! Doc may have a different answer than I have, but I always go acoustic before electric. So I would get the traps(because I know they help), and If I had anymore problems I would get the eq later. A good eq is not that expensive( I paid $125 buck for each of mine) and if the traps don't take care of all the acoustical problems, then an addition of a eq, along with the traps, probably can.

OK, Sir T. You say traps. If I were to get traps, then I should start in the front corners of the room?

Another question, or two, if you don't mind answering. Some say size doesn't matter. Does altering the diameter of the trap affect the absorption rate of various frequency? If I have a boom at 85hz is there a particular size of bass trapping that will work best? Or is it like everything else in audio where you buy, listen, evaluate, get pissed off, buy some more?

Thanks again, Your Terribleness.

THOB

[Richard Greene]

A dedicated parametric EQ for a subwoofer costs as little as $120 + perhaps $60 more for a Rat Shack sound meter and a test CD with 1/6 octave (or closer) spaced sine waves. I don't recommend using a cheap digital parametric EQ such as my Behringer Feedback Destroyer for full-range speakers because it will cause a small deterioration of sound quality in the mid-range and treble. Not something I'm looking for.

A parametric EQ will allow you to flatten all bass peaks at one listening position simply by launching less bass from the speakers to compensate for in-phase reflections that make the bass too loud at that seat. Since you are using EQ to reduce the SPL at some standing wave frequencies, the room ringing at those frequencies will fade to inaudibility faster than before EQ.

Whether EQ corrections improve or deteriorate the bass frequency response at other seating positions depends on which opposing surfaces cause the standing wave.
In general, EQ set for one listening position is more likely than not to improve the bass at another listening position.

EQ is obviously most effective for two-channel audio where only one listener can sit in the sweet spot at one time. With home theater, the more listening seats you have,
the more likely EQ set for one seating position will make the sound worse at one or more other seating positions.

Bass traps work on bass peaks too ... and also on bass nulls ... and on room ringing (slow decay) at ALL standing wave frequencies.

However you will usually need to fill 2% to 3% of a room's total volume with tubular bass traps to flatten the bass frequency response enough so that EQ is not needed.
That may require 12 to 16 tubular bass traps. Two corner bass traps will have a barely measureable effect on bass frequency response (although you may notice the room ringing is somewhat damped). Four corner bass traps should cause a small effect on the bass frequency response.

The best solution is to use as many corner bass traps as feasible (usually not many if the room is shared with a female) plus a dedicated subwoofer EQ.