why are two subs harder to place than full range?

iplaynaked offers the best first cut for my situation, and i appreciate the advice. if that doesn't seem to work i'll wait for my back to heal and start moving some furniture and listening to the sub in different positions. btw. my room is about 14'x 23' with 12' vaulted ceilings. i'll be using a pair of tekton design fostex 167e single driver speakers on the short wall and two cheap aural ecstasy subs (i expect not to turn them up very much) listening at approximately 9 feet away. thanks again everyone.

magfan, in my last apartment that is almost exactly where i had my, at the time only one sub, and in the much smaller room i had huge bass with almost no volume (xover @ 60hz) and what seemed good integration (at least it didn't seem to take away from the sound of the tektons running full range, just an addition of lower frequencies).

First get a dolly so you can easily roll it around. In most rooms, deep bass does not couple in the same plain as the mids/highs. If you notice, most really expensive speaker systems have separate subs and a XO

If you use one sub, try to place it on the right side. NOT IN A CORNER.

The wringing of the hands is worth it

GOOD LUCK

Whatever works in THAT particular room.
/ listen / move sub / listen some more.
repeat until satisfied. Than leave it alone
for a while.

btw, here is something some of you may not already know concerning the use of subs with t-amps http://www.audio-magus.com/help_answer.asp?ID=20#135

although i didn't know this and connected speaker level anyway, my amp seems to have not suffered damage.

Generally fullrange speakers offer fewer placement options than two subs would, but on the other hand the designer probably has a pretty good idea of where they will be placed in the room. With dual subs, the range of possible placement options expands enormously as compared to a pair of fullrange speakers.

If you can crossover at or below 80 Hz, and with a 4th order lowpass filter on the subwoofers, then you have a great deal of flexibility regarding subwoofer placement. If you have to cross over higher and/or do not have a steep lowpass filter, then keep the subs near the main speakers. The point of this paragraph is, you do not want to be able to hear the subs as separate sound sources due to lower midrange energy coming through them.

Assuming you can place the subs as you see fit, yes there are several different placement strategies. I favor asymmetrical scattering to average out the room-induced peak-and-dip patterns generated by each low frequency source. You want the subs to be spread out in at least two dimensions, relative to the room boundaries. As the number of spread-out low frequency sources goes up, the importance of the exact placement of any one of them goes down. So in practice, multisubs are usually more placement-forgiving than a single subwoofer is.

Duke
dealer/manufacturer