Speakers to alleviate room anomolies


I have a suckout of 8db from 58 -70 hertz which is taking the life out of the music. I currently have Von Schweikert VR7SE an added a velodyne dd18 which took away the problem. It gave the bass energy in my room of 30 x20x10. It seems I do not need the big cabinet speakers[VR7SE] if the woofers aren't throughing enough. Speakers with active woofers like the evolution acoustics mm2 have been recommended. Any other ideas of speakers in conjunction with the velodyne dd18 to make my room sing again.
128x128snook2
Rleff, in general it's desirable to have a lot of low frequency sources in-room, as long as you aren't stressing the main speakers and as long as you aren't over-emphasizing some portion of the bass region or otherwise creating a problem (like your wife says you're sleeping on the couch). Of course in some cases it's more desirable to relieve the woofers in the mains of having to make long bass excursions, so the best answer depends on the specific situation.

Snook2, it doesn't matter how capable the main speakers are, the room's effect will dominate in the bass region. There are four approaches to smoothing the bass that you can use singly or in combination:

1. Speaker and/or listener re-positioning. By all means visit Jonathan Tinn's speaker placement page. If it's aesthetically acceptable, you might try an asymmetrical setup. Imagine looking down on the speaker-listener-speaker triangle within your rectangular room, and imagine rotating that triangle clockwise or counter-clockwise maybe 15 or 20 degrees. Don't go all the way to diagonal; that would again be symmetry, and asymmetry is usually your friend in the bass region.

2. Add low frequency damping in the form of bass traps. This works well at not only taming peaks but also at filling in dips. I don't think bass traps can eliminate an 8 dB dip, but they can make it shallower.

3. Equalization works well for a small listening area, but it's a two-edged sword if good sound in a wide range of listening locations is a high priority. You see, boosting a dip or notching out a peak in one location can result in boosting a peak and notching a dip in another. The better equalization systems use readings taken in a wide variety of microphone locations and then calculate the appropriate EQ curve. Global (room-wide) bass problems are good candidates for fixing with EQ, but in my opinion localized bass problems usually are not.

4. You can use multiple (imho preferrably asymmetrically placed) bass sources, which works for reasons I've described in my previous post. Credit to Earl Geddes for teaching me this approach. Note that multisubs reduces the variance from one listening location to another, so that any remaining problems are likely to be global and therefore are good candidates for fixing via equalization.

Bob Reynolds, what I meant by "peak and dip pattern" is the frequency response at a specific microphone or listener location, rather than the room-wide pattern. If we could look at a map that showed the frequency response throughout the room, that "peak and dip pattern" would indeed depend only on the source(s) and the room - not where ears or microphones are positioned within the room. My apologies for the ambiguous wording.

Duke
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Bob_Reynolds: I like poking fun at Duke as well. He and I go back a long time.
Just 8db suckout at a certain frequency is not enough info to sort the problem out. The 8db drop could be from bass cancellations, bass leak or an object absorbing too much. THere are other parameters Rt 60, impulse response when you are looking to solve this problem. I am no expert and currently working on room issues too. Sub is ok but probably not the best solution. Best i to get professional consultation.