That's a speaker amp, you really should be using a subwoofer amp for this. The low pass crossover is highly recommended with shakers, typically want to cut it off around 50 Hz. When the shaker plays higher than that, it can be disjointed with the rest of the system. Cheap speaker amps may also cut off bass frequencies. From the Amazon review, it looks like this amp is -6 dB at 75 Hz and cuts off at 55 Hz... so it's really a bad amp for your purpose. I'd return it and get a sub amp.