One big subwoofer or two weaker subwoofers?

Sugarbrie's first paragraph makes an important about quality. Cheap subwoofers are worse than none, as a rule, since they tend to degrade the sound from the main speakers.

When it comes to subwoofer design, however, one large powerful subwoofer isn't necessarily the best approach. Subwoofers with several smaller drivers (in the 8-10" range) have the virtue of being able to move a lot of air, while the smaller drivers have less mass and thus can respond more quickly than a large driver in the 15-18" range. Multiple drivers in a subwoofer (assuming it is well designed) also offer the advantage of averaging out the resonance points, thereby yielding a smoother frequency response (Vandersteen subwoofers, for example, use three 8" drivers).

The primary advantage of using a stereo pair of subs is that they load the room more evenly, thereby reducing the resonant nodes in the room. A stereo pair of subs also presents a much more realistic sonic image, since deep frequencies may be coming more from one speaker than the other. (When I bought my first Vandersteen subwoofer, I was very pleased with it, and bought the second one expecting it to just add a bit more "oomph" to the deep bass. What I experienced was a MUCH better overall sound reproduction that provided spatial clues.)

Assuming your budget allows you to buy a good quality of stereo subs, I would personally recommend that approach to having a somewhat more expensive single sub.

There are so many issues to consider here. What is the cross-over point? What are the room modes like (2 subs make cancellation of problematic modes much easier)? Is it 2 channel or multi-channel? Here is a link to a paper we wrote on loudspeaker placement. Loudspeaker Placement on Audioholics It may answer a few of your questions--may raise a few more.

When I trying to decide which way to go, I called Sumiko, the US distributor for REL. They stated without a doubt, that one Stadium III was better than two Storm or Strata III's. I purchased a Stadium III and couldn't be happier. I'd go with a sub that has flexible cross over points. REL's go down to 22hz. I never thought I'd have my sub set as low as 23hz, but that's were it ended up. Like a previous post stated, a lot does depend on your main speakers.

One better sub is allways allways better than two of anything else equalling the same price! Assuming you do not buy too big of a sub for the room and that the one sub in it's best position in the room, provides the correct amount of bass at the listening position! This sometimes is not possable no matter how big the sub is in which case two (in mono!) will smooth out the room nodes. Stereo subs is an absolute joke and shows no knowledge of how bass loads a room. Stereo bass with evenly placed subs will just cancel out the bass at the listening position period. TAS covered this topic perfectly a few issues back so the statements I make can be proven by those who should know.

How about two big subs instead of two small subs or one big sub? If you want low frequencies with authority, you can't do that with a small box and keep things "tight" with good transient response : ) Sean
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