the simple answer is yes...
but it depends on what the amp is capable of (4ohms, 2ohms, 1 ohm, etc...) and what the subwoofer impedance is. i currently run four 15" subwoofers off one channel. they are wired in paralell and are 4 ohm single voice coil subs. this creates a 1 ohm mono load.
your application may be different. it depends on your amp and subs.