I have an 02 Bonnie and It has a Monsoon Radio In it with the amp. The Rear deck speakers blew (Broke the baffling around the speaker) So i bought some Infinity speakers to replace them. And the sound is horrible.... Hardly any bass out of them like the factory till radio turned all the way up to its max with the rear speakers only playing and the treble and mid at -6 the bass at +6. Any ideas as to why this is and how do i fix the issue.

well i believe your monsoon speakers were 2 ohm and the infinities u are using r 4 ohm...

That wouldn't matter to the point of what he is talking about. Sounds like he has them wire backwards to me.

I'm pretty sure those infinity speakers are 2 ohm anyway. They usually are. Wiring backwards won't matter as long as they aren't opposite of eachother. Factory premium systems usually have more of a component set up than a coaxial design. I have heard tons of my installs lose midbass when I installed aftermarket speakers where premium system speakers were. I think you basically had a pair of six by nine woofers and now ya don't

are your rear speakers components? did u hook up your new speakers to the tweeter wires. Not sure if what im saying makes sense. but i know what i mean.

Yeah, the 6x9s on the stock Monsoon setup were called "subwoofers". The amp only let the lows go through them, while the mids and highs all went through the front and rear doors. You still shouldn't lose ALL your bass though.

well if u hook up coaxial 6x9'* to the tweeter wires the crossover is going to cut out all bass

Well infinity speakers want to see about 150 rms and monsoons may only need 40-50. Do you see what I'm getting at? In most cases a driver at optimal power will perform better than one under powered

try but u shouldnt loose much bass from Under powering. My deck only puts out 50w max and my 6x9'* are 220w max i believe and i still have good bass. Are u replacing ur stock HU?

Be that as it may, the only thing that changed in his system was his rear speakers. Unless in a rare circumstance where the amps rear channels are damaged there is no reason to blame anything other than the speakers along with the way the factory amps crossover is set. At this point him changing his radio or not has nothing to do with the cause at all