Audio Artistry Beethoven Elite

It's been a long time and I don't remember using a separate amp for the subs. However, looking at the crossover, on Bing Images, it appears that two stereo amps are necessary. Plug the output from your preamp into the crossover (left/right in) and route the left/right outs to the main amp and left/right sub-out to the subwoofer amps. Trying to remember what amp I used for the subs.

Goof Luck 

After much pondering, I believe I employed an Adcom GFA-535 for subwoofer duties. Seemed to work well. I know it wasn't anything fancy.

Thanks to both of you. I will try it and i have a friend who have some knowledge on speakers. I will get help so I will not destroy these speakers.