Room acoustics have an enormous impact on the sound of speakers, including subwoofers. A phenomenon called “standing waves” makes bass response uneven from place to place in your room. To experience this for yourself, put on a CD with a strong, consistent bass line. Notice how the volume of the bass goes up and down as you move around the room. Stand in one place and then squat down-you will probably notice that the bass changes in the vertical plane as well!
Because the subwoofer’s location affects how standing waves are created, the first step to getting accurate bass response is finding the right spots for your subwoofer and your listening position. We’ll share a few guidelines that may be helpful, but in the long run nothing beats trial, error and your own two ears.
Stick It In The Corner
This is the advice most often given and it certainly will yield loud bass. But corner mounting may make the woofer sound “one note-ey,” and boomy on music. If lack of bass volume is your biggest subwoofer problem, this may be the answer for you.
Avoid Sitting Up Against the Wall
Bass waves build up and “hang out” at room boundaries (walls). Your system will sound thick and heavy when your listening chair is up against a wall. If you must sit against the wall because of furniture layout, turn down the volume of the subwoofer a bit to compensate.
Avoid Symmetrical Placement
“Avoid putting the subwoofer the same distance from two walls. For example, if you have a 20′ wide room, don’t put the subwoofer 10′ from each wall. Similarly, don’t put the subwoofer near a corner and equidistant from the side and rear walls. Instead, stagger the distances to each wall.”1
Put The Subwoofer As Close To The Main Speakers As Possible
Even though bass sounds are non-localizable, cabinet resonance and other factors conspire to make this less true in practice than in theory. It’ll be much easier to get seamless blending between sub and main speakers if they are on the same side of the room. If possible, put the subwoofer behind the plane of the main speakers. At very least, keep the subwoofer in the front half of the room.
Here’s An Old Trick
Put your woofer in the same spot as your listening position. It’s best to raise the subwoofer off the ground to seated ear height (use a sturdy, non-resonant platform). “Play a piece of music with an ascending and descending bass line such as a ‘walking’ bass in straight-ahead jazz [see recording suggestions]. Crawl around the floor on your hands and knees…until you find the spot where the bass sounds smoothest, and where each bass note has about the same volume and clarity. Avoid positions where some notes ‘hang’ longer and/or sound slower or thicker than others. When you’ve determined where the bass sounds best, put the subwoofer there.”1
Use Two Subwoofers
Using two asymmetrically placed subs will minimize the effects of standing waves in your room, yielding smoother bass response as well as better dynamic range. If using two subwoofers, you must use the identical model of subwoofer. If two different models are used, even from the same manufacturer at some points they will help each other, at others they will fight each other causing a uneven response.
One Note Of Caution
Most subwoofers are magnetically shielded but not as “tightly” shielded as say a center channel speaker because of their more powerful magnets. This may damage your TV if placed too close to the set (though plasma, DLP, LCD and front projectors are not affected). Select an unused video input on your TV to bring up a single color screen. If you see any color distortion anywhere on the screen, an unshielded speaker is too close to the set and should be moved away from the TV until the color distortion disappears.