Recording Music


Hi all. First time on this because I'm somewhat stumped.

I work at a school and I want to start recording kids playing music/singing. I'm using a Behringer Xenyx X2222USB mixer plugged into a PC. My problem is I have one set of speakers and they are in the same room as the microphone recording, say, vocals. When I'm recording I have to turn the speaker's power off to they don't bleed into the mic. What I want to do is to be able to turn the sound off the speakers without having to essentially unplug them. I have Main Out, Sub Out and Control Room out. Is this even possible?