Hi Kenny:
The RSUB300 does not have an internal low pass filter (no crossover internally), so you need a dedicated Subwoofer amplifier like our SMP500 which gives you a high cut filter, gain control and phase switch. The AMP200 is a full range two channel amp that would depend on the natural roll off of the subwoofer which might be as high as 300 to 500 Hz. You want a Subwoofer, not a Mid Woofer.
TL/5472