I have a '95 Accord LX

My back speakers went out (i'm not sure if they went out at the same time), i was wondering what should i check for / procedures to see where the problem lies...i also installed a new head unit about a year ago if that helps

also, i bought this car used, and i think it might have an alarm (becuase it has that little red light bulb on the driver side console), and even a remote starter

however i don't have the remote (again, bought it used) i was wondering would there be any problem if i try to install a new keyless entry or remote starter?

any help's appreciated, thanks