speaker level sub hookup on class D?

I suspect that you can but I really wonder why. The sub will only convert that input to line level for its own internal amp and processing. The additional amp is adding nothing except its own noise and distortion; low though that may be, there's no reason to add it.

Do you have a line-level mono signal for the sub?

Kal

Outputs on Icepower amp behave the same way as outputs of the bridged amplifier - both terminals of each output are active. If your Velodyne has both speaker level inputs referenced to same level (internal GND) it will short Icepower amp. This connection is only possible if Velodyne speaker level inputs are balanced or floating/isolated.

I second what Kal said - why bother? You have line level mono input and line level stereo inputs on your Velodyne. As long as you have mono signal out or two stereo outs you can make safer and better connection.

Good to know.....ICE is 'half bridge' topology and makes sense for the whole thing to 'float'.