advantages/disadvantages of 2 subs.....

>Room 20 x 16...thinking of 2 10" subs...would this be wise?

For what purpose? Ported/passive radiator, bandpass, or sealed?

For most music (even electronic music) peaks in the last octave don't have 1/10th the power that they have in the rest of the spectrum. You should be OK.

I don't know about organ music.

For reference level home theater a pair of 10" sub-woofers will be woefully short. A pair of 15" sub-woofers there are short.

Phase,

If you haven't noticed from the above post, I might also have pointed out that Drew is an excellent resource for this question as is member Shadome.

Dear Phasecorrect: Which speakers do you own? do you wnt to integrate the subs for a music stereo system or a home theater?

Regards and enjoy the music.
Raul.