what speakers

[08mega]

Hey guys IM new to this whole audio thing. Recently got my hands on a old Kentwood system.I got kc-105 control amp, km-205 power amp kt-75 synthesizer and a single disc player. Also got a set of techwood speakers with it. But not all speakers work. The boxes have a15" pro studio subs both produce sound. A mid range speaker the mounting hole is 4 1/4 neither one produce sound. And then tweeters in a 2" hole. Only one produces sound. I'm just going to put this in a shop so I don't want to spend slot of money getting them working. The mid ranges say 8 ohms on them. I don't know any more info on rest of speakers right now. But have had no luck finding replacement speakers or a clue what speakers I can replace then with two make everything work. Not much luck finding info out on the system itself since so old. So if anyone can help me I would appreciate it. Sorry for the newbie questions.