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speaker/room bass modes

Question: If a room has a 60hz suckout with speakers "A" which have the woofers one on top of the other at the bottom of the cabinet, and you replace them with speakers "B" which have a different woofer configuration, one low and one high on the baffle and possessing a different crossover and radiation pattern, and place them in pretty much identical postions within the room, will the suckout remain? Does the room have the final influence on reproducing the frequecy or can it be overcome with a different delivery from the speaker?
rhljazz
rives
953 posts
 
The two answers already posed are correct. However, there is a third answer (not direct at what you said, but it works). Bass traps. Most people think of bass traps as taking bass energy away, however, there are types of designs that actually change the phase of the bass energy and thus create different interference patterns. The result is both a reduction in the peaks and an increase in the nulls. Will it solve the problem? Don't know without a lot more information, but there's a good chance it would.
rhljazz OP
1,117 posts
 
I am using a digital Radio Shack meter and Stereophile test cd3 which I've been told is not very accurate in the bass. I know Rives has a test cd calibrated for the analog Radio Shack meter. I only have the digital meter and wonder if the Rives disc would be a better source for making measurements than the Stereophile tracks? Using my current test equipment, I referenced 80db at 1khz and my greatest variation is -7db at 63hz and +4db at 40hz.

The system sounds good but lacks some punch. I'm always looking for improvements.
shadorne's avatar
shadorne
7,333 posts
 
That is not bad freq response - probably better than average. I see you have some acoustic treatments already. Have you considered a PARC?
rives
953 posts
 
The Rives CD works with the digital meter as well, though it's calibration was done with the analog. The digital is within 1 to 1.5 db the same response as the analog in all the tests we've done.
dcstep
1,518 posts
 
I agree with everything said so far; however, I'd like to add that interaction with the wall behind the speakers is hypercritical, particularly if the speakers have rear-firing ports. You can excite a node and then attenuate it by moving a speaker fractions of an inch. See the thread about the Sumiko speaker set for details of the successful experience I just went through.

I think that optimizing the set, given your speakers, room and seating position is a first step, then work with room treatment.

Dave
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