My home receiver came with a microphone. You plug it in and the receiver blasts noise through the speakers, and comes up with EQ to compensate automatically. Th

My home receiver came with a microphone. You plug it in and the receiver blasts noise through the speakers, and comes up with EQ to compensate automatically. This wasn’t an expensive receiver, either. If you want a more scientific approach, you can use a tool like Room EQ Wizard, which is free—although it works best if you have some kind of flat response microphone, or calibrated microphone with a known response curve. (I’ll also add that you’re compensating for crappy acoustics in your room as much as you are compensating for crappy speakers.)