oem amp

Do most of the amps have orignally amplifier? How can you know if the car has it or not? I installed a subwoofer on my mercedes and the sub sounds like crap, why? I connected my RCA adapter to the back speakers is that ok? thanks

how can i test the polarity? I got a MTX mono amplifier 1500watts, I got the same thing in my honda sounds awesome. The batter of the mercedes is at the back so I connected there and the RCA adapter I connected from the back speakers since I wouldn't find the speaker wires from behind the headunit. When i put it up  it give distortion and sound wierd can't really explain.

You can test polarity with a 9v battery. Hook up a wire from the + and - of the battery to what you think is the + and - of a speaker. If the speaker Pops outward (away from the magnet on the back) then the polarity is correct and you have correctly identified the + and - of the speaker. If the speaker Pulls in (towards the magnet on the back of the speaker) then you have the polarity reversed. This is how you can identify which terminal on the speaker is + and - when they are not marked (as most factory speakers are not marked). Now that you know which is + and which is -, do you still have the correct leads going to the + and - of the RCA adapter? Another question, when you say "RCA adapter", are you referring to a Line Out Converter (LOC) like this one, or did you just splice an RCA plug onto the end of some wires for a homemade adapter? If you did the latter (homemade adapter) then you deffinately need to get a LOC. Even if the car doesn't have a factory amplifier, the headunit is still putting out an amplified signal (High Level signal). If you fed that signal into the RCA Low Level inputs of an aftermarket amp without converting it first, then that would cause a lot of distortion. Third question, why wouldn't you find the speaker wires from behind the headunit?Squirrel

"No more Cpt. Kirk chit chat"

If its too loud, then you're too old

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i couldn't find it because there is alot of wires that are the same color.. i used a (loc)..

If the polarity is correct (meaning you wired the + and - to the LOC correctly), then you may have to adjust the gain settings on the LOC. It adjusts the signal to properly match the amp.Squirrel

"No more Cpt. Kirk chit chat"

If its too loud, then you're too old

Donate to the12volt.com

I checked everything was connected right at this point I'm thinking that since I connected the (LOC) to the back speakers right directly from the speaker, the factory amp may make it sound like this. What do you guys think?

what year mb do you have cuase all new style mb;s have factory amps now the back speakers alone are crossed over that is why you are getting crappy sounding outcome,. you have to connect to the front door speakers at the output wires of the amp when adding a after market amp and keeping the factory amp let me know i can help mail me. Jon

Installer/Help Technician

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mecp certification is not always needed. I have it and it has not helped me out at all. my experience out shines it.