Yeah. HTIBs are usually rated with:

10% > THD
1 khz Test Tone
into a 3 or 4 Ohm Load.

I had a 600W Sony HTIB before my Axiom/Denon system. It just doesn't compare to:

450W
0.08% > THD
20hz - 20Khz Tone
8 Ohm Load
not including sub (with its own Amp)

I seriously could not get my Sony to fill the room without distorting enough to become unpleasant.

Snazzed

M22, VP150, QS8 <--all v2
Sub: Outlaw LFM1-Plus
Denon AVR1910, Sony X900-65"