DMHenrie said:
He wants home theatre and has some JBL 4311's and som e DQ 20's.
He thinks the DQ20's are superior and that they are flatter in
response, although we don't know how he knows this.

Have you measured either of your speakers with an spl meter and a set
of test tones?

At any rate you should probably use the speakers that are most
efficient.

Good subs can be had from SVS, Hsu, Velodyne, Adire, and PSB. You can
also build a sub using Adire's superior woofers, although there are
others that will do. I like Adire becuase they have the most bang for
the buck IMO and they offer detailed info on how to build a good sub.
You can actually build as good or better as you can buy when it comes
to subs. Personally, I recomend building one from sonotube. It's
light strong and no standing waves, since it's a cylinder.

For surrounds check into Pro audio stores and look into some powered
speakers used for monitoring.