why are two subs harder to place than full range?


sorry if this is a dumb question, but i notice that whenever someone talks about getting stereo subs there usually ensues much hand wringing over placement and room modes, etc., but this rarely is the case when someone talks about full range speakers with large 10 or 12 inch woofers (with or without built in amps for them).

Is there a sound technical basis for this different treatment or is it merely convenience, i.e., since subs can be moved about separately from main speakers, then it makes more since to talk about eliminating room modes by moving them around?

I'm getting a second sub for a rather large vaulted room, have an injured back, and would rather minimize what seems like a rather long process, at least for the time being by just keeping the subs with the mains.

thanks
thomp9015
If you Google "Richard Hardesty" and "Vandersteen" you should find soem well written articles on the theories behind subwoofer placement, and why separate subwoofers make for much better bass performance with optimal midrange in the main speakers - the location for both are often not the same. If I reacall correctly, two subs are much better than one for a variety of reasons - not having to do with "deeper" bass but more linear bass perfomance.
I'm getting a second sub for a rather large vaulted room, have an injured back, and would rather minimize what seems like a rather long process, at least for the time being by just keeping the subs with the mains.

The best spot is often away from the corner and close to the side wall and a few feet in front of your main speakers (assuming you have full range) I find the best way to integrate is to run the main speakers full range if they are big bad boys with big sub sized woofers themselves.

I would never place a sub or main speakers in the corner unless you want pure impact for HT - as you are talking room modes galore...
Although I'm only using one sub I did quite a bit of experimenting with placement. The corner placement was the worst for me. My sub is between the speakers with the driver on the same plane. By far the smoothest integration.
The sub brings almost as many problems as it solves. To give you peace of mind connect the system to a room correction device. Some not only measure and EQ to compensate for the acoustics, but will act as a crossover too.

Some are simpler than others to use. I can recommend the Lyngdorf room perfect system for its ease of set up and excellent sonics. It will save a lot of fiddling about. Speaker placement is then irrelevant.