Subwoofer Placement

I often see people ask in audio forums where they should place their subwoofer. It's impossible to say where the best place for a sub is in your room without being there to measure. There are just too many variables such as where the main speakers are, where you sit while listening, what the crossover frequency is set to, how much bass trapping you have or are willing to have, and so forth.



When I bought my first sub, a Carver Sunfire a few years ago, I tried a variety of places in my 25 by 16 foot living room. Then I looked in the manual which said to put it in one of the front corners. Bingo, that was clearly the best place. A year later I replaced the Sunfire with an SVS PB12-Ultra/2 subwoofer (photo) and noticed that its manual also said a front corner is best. By then I didn't even need to experiment. I put it there and it's even more fabulous than the Sunfire.

That said, a front corner is clearly the loudest location, but it won't be the flattest unless you have a fair number of bass traps. Loud works for me! But I also have 44 traps in my living room home theater, and all those traps reduce the peaks and ringing you get with corner placement.

The only way to know for sure which place is best is to measure the response as you try different locations. But you need to measure to a high resolution, such as at 1 Hz intervals. This can be time consuming because moving the sub even an inch or two can make a real difference. So you end up measuring, moving, measuring, moving, and so forth for the better part of an evening. You can get software to do this more efficiently. I recommend ETF and R+D for Windows ($150), FuzzMeasure for Macs ($150), and Room EQ Wizard which is free and works with both Windows and Macs.

Another method is to put the subwoofer at the listening position on a chair, then play some bass-heavy music and crawl around on the floor listening for where the bass is the most even. Once you find the best place by ear, put the subwoofer there. One problem is this works only with smaller subs. Another problem is the key of the music affects what you hear. If the music has bass tones that align with the room's modes, this method can work pretty well. But if the music is in a key that doesn't excite the room modes, then other music that does excite the modes may sound unbalanced.

The bottom line is the only way to know for sure which sub placement will give you the flattest low frequency response is to measure.

Copyright 2008 Ethan Winer.