An EH reader sent in this question:

I would like to use 1 amplifier to run my home stereo speakers and another amplifier to run my subwoofer, how would I combine the two inputs?

There is a huge unknown here. 

Are you using a preamplifier to receive the signals from the source devices and send them to the amplifiers?

Are you using a passive subwoofer? (If you are using an active subwoofer it already has an amplifier built in).

Does your subwoofer have a crossover switch or knob to adjust the output frequency? (commonly the dial will range from 20Hz to 100Hz).

Do your amplifiers have a loop/line level out?

Do your amplifiers have any crossover adjustments?

These all make a difference in the set up.  If you can elaborate on the equipment we can provide a solution.

Best,
Mark C
markc at orangeproav dot com