hehe it plays music......
the only thing with hooking up 8 ohm speakers to an amp that can handle a 4 ohm load is that the power may be reduced...no harm should come to your speaker though...you would need to hook up to identical 8 ohm subs to the amp to get a 4 ohm load which will inturn providing tha the amp is getting enough juice put out the rated power of the amp...likewise most amps can be bridged or are stable to 2 ohms where the power output is increased..
4 ohms is the what the amp is stable too..any induced load higher then that or equal to it will ok...loads lower then that may damage amp and subs..