darthkringle,

This reminds me of some subwoofer testing I did quite a few years ago with kcarlile. I used my computer to generate test tones starting at 10Hz and upward. On the extremely low tones, the woofer is mmoving slow enough that your ear can make out the individual in-out motion of the cone.

I don't think you should be worried about any "bottoming-out", since the digital amp's algorithms should prevent that.