bmw logic 7 replace amp

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=130995
Printed Date: May 15, 2024 at 2:26 AM

Topic: bmw logic 7 replace amp

Posted By: Thack79
Subject: bmw logic 7 replace amp
Date Posted: March 22, 2012 at 9:02 PM

Have a 03 745i. My question is can the logic 7 amp be replaced with an aftermarket amplifier to run the interiors. I understand the system has a fiber optic wire from the radio. Is it a way to replace it with a rewire?

Replies:

Posted By: soundnsecurity
Date Posted: March 22, 2012 at 9:46 PM

if the stock system is fiberoptic then you will need something like a JL audio cleansweep which takes all the speaker wires and combines their signals into a set of full range outputs that can be used by an aftermarket amp.

do you plan on replacing the factory speakers? because if you plan on keeping the stock speakers then there really is no point in replacing the amp.

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Posted By: Thack79
Date Posted: March 23, 2012 at 2:10 PM

well he has no sound coming from his system at all and the guy bought a factory amp from the dealer and now the new amp has went out after little under a year. I know its not many options for this car. Ive dealt with another fiberoptic car (volvo xc90) but they made a dash kit for it so it wasnt really a problem. But they dont mae a dash kit for this car. Running out of options for this guy cause i doubt he got the funds to my to custom the dash to place a new radio somewhere (nor do i feel like doing it).

My intent was that i hope he has one channel on the factory amp thats working so that i could tap that for a input to the rcas to the new amp and chennel the other speakers. But if NOTHING is working then i have no clue.

Thoughts???

Posted By: soundnsecurity
Date Posted: March 23, 2012 at 2:29 PM

have you tested the speakers for shorts? even if he has one or two good channels left on his amp they probably wont be full range outputs because the amp uses internal crossovers that go to each individual speaker. thats why i said you would need something like a cleansweep to take all of those filtered outputs and make one full range input to feed the new amp.

long story short, you need a working factory amp to be able to install an aftermarket. OR, a total system overhaul and you will have to relocate the factory radio to keep the fiber optic loop intact or your instrument cluster will be light city.

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Posted By: Thack79
Date Posted: March 23, 2012 at 2:37 PM

Thanks man. great info!!!

Posted By: Thack79
Date Posted: March 24, 2012 at 5:44 PM

Turn out that it's just the front speakers in the doors that are not working. Still an logic 7 amp issue?

Posted By: wysiwyg
Date Posted: March 24, 2012 at 10:25 PM

I think it is an amplifier issue. They are notorious for dropping channels one at a time untill they all fail.