E90 Logic 7 testing question

borisivan · 01-11-2016, 11:24 AM

Hi,

I have a 2010 E90 with the Logic 7 speaker upgrade. Love it.

Or at least used to love it... something has changed and I can't quite place my finger er, I mean ear on it.

Things sound different, like one of the speakers is dead, though I can't figure out which one. I've reset the equalizer, etc, and tried to troubleshoot by adjusting the sliders to front/back/left/right to see if any obvious speaker was totally dead -- can't seem to find it. I hear noise coming out of all the speakers I can see, though if there are multiple drivers in a speaker it might be possible I'm only hearing one of them.

Is the subwoofer under the front seats? That's the only one that I can't get my ear close enough to.

Is there such a thing as a 'test cd' for these cars, where it will cycle through each speaker & driver so I can easily tell which speaker might be a problem?

I was also wondering if there is a 'typical' set of problems that people may have had with the L7 system after several years, like "oh yeah, check fuse A88 -- that is typically the culprit", or any other advice you might have.

It's not a high def radio problem, re: going in to low def -- I have the same "something is wrong with the speakers" feeling whether I'm on my ipod or over-the-air radio, so I'm pretty sure it's a speaker (or processing). It's as if a certain 'range' of MhZ is missing. Some songs that I know by heart just seem to have a few things "missing" or muted.

Any suggestions?

maddmatt02 · 01-12-2016, 12:14 PM

Download some test tones and play low tones while you balance/fade around, then play higher tones doing the same thing.

borisivan · 01-12-2016, 01:52 PM

If I do narrow down a specific speaker that isn't 'dead' but instead it's just 'different', it's starting to look like it might be an AMP starting to go bad, based on some of the other posts I've read.

Regarding 'verifying' that it's the AMP, is it possible to run a test with a voltmeter and verify what voltage is coming out of each of the pins on the AMP's 25 pin connector? Or will disconnecting that connector (to the AMP's output?) stop the AMP from working?

Would love to prove that a particular output on the AMP is acting flaky before I ship it off to be repaired.

01-11-2016, 11:24 AM	#1
borisivan craptastic 20 Rep 281 Posts Drives: 2010 335xi Join Date: Jul 2007 Location: hell in a handbasket iTrader: (0)	E90 Logic 7 testing question Hi, I have a 2010 E90 with the Logic 7 speaker upgrade. Love it. Or at least used to love it... something has changed and I can't quite place my finger er, I mean ear on it. Things sound different, like one of the speakers is dead, though I can't figure out which one. I've reset the equalizer, etc, and tried to troubleshoot by adjusting the sliders to front/back/left/right to see if any obvious speaker was totally dead -- can't seem to find it. I hear noise coming out of all the speakers I can see, though if there are multiple drivers in a speaker it might be possible I'm only hearing one of them. Is the subwoofer under the front seats? That's the only one that I can't get my ear close enough to. Is there such a thing as a 'test cd' for these cars, where it will cycle through each speaker & driver so I can easily tell which speaker might be a problem? I was also wondering if there is a 'typical' set of problems that people may have had with the L7 system after several years, like "oh yeah, check fuse A88 -- that is typically the culprit", or any other advice you might have. It's not a high def radio problem, re: going in to low def -- I have the same "something is wrong with the speakers" feeling whether I'm on my ipod or over-the-air radio, so I'm pretty sure it's a speaker (or processing). It's as if a certain 'range' of MhZ is missing. Some songs that I know by heart just seem to have a few things "missing" or muted. Any suggestions?
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01-12-2016, 12:14 PM	#2
maddmatt02 Private First Class 8 Rep 117 Posts Drives: alpine white e90 Join Date: Jan 2016 Location: WA/USA iTrader: (0)	Download some test tones and play low tones while you balance/fade around, then play higher tones doing the same thing.
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01-12-2016, 01:52 PM	#3
borisivan craptastic 20 Rep 281 Posts Drives: 2010 335xi Join Date: Jul 2007 Location: hell in a handbasket iTrader: (0)	amp vs speakers If I do narrow down a specific speaker that isn't 'dead' but instead it's just 'different', it's starting to look like it might be an AMP starting to go bad, based on some of the other posts I've read. Regarding 'verifying' that it's the AMP, is it possible to run a test with a voltmeter and verify what voltage is coming out of each of the pins on the AMP's 25 pin connector? Or will disconnecting that connector (to the AMP's output?) stop the AMP from working? Would love to prove that a particular output on the AMP is acting flaky before I ship it off to be repaired.
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