Anyone with a high-end home theater sans sub?

I don't suppose adding a sub in my small room would even generate clean signals that low beecause the room is too small for those frequencies to form correctly, am I right? That is why in my room; 5 full range 5200's sounds better then when I had only 3 full range (8000's and 5500hc) up front. If I have crunching bass now, I worry that a sub will just muddle things up.

If your system main speakers are measurably flat to 20hz, then what is the point of the sub?

What is the best way to test how low the system can go to using an spl meter?

Flrnlamb,
As you point out, the DSP8000s (like most full-range speakers) include separate drivers for various frequency ranges. If your implication is that any speaker that includes drivers that play the lowest octave automatically include a "subwoofer", then this discussion is moot. However, Quicke's initial post questioned the need for a separate subwoofer (not just full-range speakers) - note his reference to a "7.0" configuration.

For the record, I don't know how loud the DSP8000's will play an 18Hz tone, but they are measurably flat down to 18Hz for as loud as I can stand in my room, so they work for me. My previous post may have incorrectly implied 118dB at a single frequency. They are specified as within 3dB from 20Hz to over 20kHz. Maximum output >118dB spl @ 1m on music material (presumably a combination of freqencies). Honestly, I'll never be able to test them at that level.

No self-respecting HT afficianado would have a theater without a sub. :)