Using two subs

The advantage to using two subs is this:

A single subwoofer will give you a unique pattern of reflection-related peaks and dips depending on where you place the sub and where the listening position is. These peaks and dips will be large enough and far enough apart to be audible.

With two subwoofers placed asymmetrically, their respective patterns of peaks and dips will never coincide at any listening position so the net result is smoother bass throughout the room.

You'll need for at least one of the subs (usually the one farthest from the main speakers) to have a 4th order crossover so that you don't hear its location.

No reason at all why you can't use two different subs. That might even result in a smoother overall response.

I use four small subwoofer modules in a system I showed at T.H.E. Show in Las Vegas about a month ago.

One disadvantage would probably be this: For a given total dollar expenditure, one big sub will usually give you deeper and louder bass than two or more smaller subs will.

Duke

I went form using one to two subs. The obvious benifit is of course more power and more apeaker. But I really can't explain it. With one sub I had bass. With two subs I have the instruments that are covered by subs. The bass appears to come form my main speakers.It's like they are not here.

Thanks for the responses so far. A little more information about my system and the potential additional sub.

Room:15W x 20L x 8H
Full 5.1 currently: All full range (Klipsch 3-way towers)
Current sub: Klipsch RSW-15 (650watts 15" passive rear firing)

I am thinking about adding a REL Stadium III for the second sub. (200watts 10" ported down firing)

A few things I like about the REL: local purchase, can be integrated easily with my 2 channel setup, and hopefully will strenghten my lows for HT.

One reason I'm doing this is because I know that Klipsch speakers/subs aren't the best at the very low end.

Am I on the right path?

Gregadd,

Setup caused the problem you experienced with a single sub. A single sub, properly setup, should disappear as well. But setup may be easier with two subs. Don't know about your subs, but I have mine turned down to a quarter scale at the sub and use the pre attenuator to match the 5.1 levels with white noise and my RS SPL meter. It can generate that felt vibration with a low pedal note or make you feel your chest is compressed with an explosion in a movie. So I doubt adding power is the reason for a second sub.

db

I went from one revel b15a to two and the difference is FAR from small.
Even though I could not hear where the sub was I could always feel the "pressure" on one side of the room was more. Adding a second sub has evened the pressure as well as aided me to level the bass response out in the lower registers.

I would never go back to one sub having lived with two now.