What power supply do these use? It's not marked anywhere on them.

Probably some proprietary mains transformer
It's a speaker system, what the fuck do you expect? A Corsair CX750?

Electricity I guess.

Speakers are analog electronics, so they're relatively un-picky about the power supply. Anything around 12V DC should work, anything over 15V might burn them out. Anything lower than 12V will work, but may not provide enough juice (if the sound seems distorted, you're short on power).

>>59066788
>>59065690
Also no thanks to these underage trolls from /b/.

>>59066882
Ok, thanks. I am trying them with a 9V adapter and it does seem to be slightly inadequate since the power light on the speakers flickers a little if I have the volume up loud enough.

Also I don't know what's with the unhelpful first two replies in here. This board has seriously gone downhill lately.