no u cant have a woofer without an amp.

amplifier channels are for the number of speakers u want to run.

for subwoofers u can either get a monoblock (single channel amp) or a two channel amp (which will be bridged into one channel)

to save space look for a good quality 8, 9 or 10 inch sub in a small sealed box

This post has been edited by zennn: Jun 9 2012, 09:38 PM