Audio hiss with professional audio

titium · 10-12-2015, 05:13 AM

Car is a 2009 135i e82.

Experiencing slight hiss with the radio off amplified at low volumes with the radio on.

After installing an aftermarket amp if I run any gain the hiss is really loud and annoying.

Does anyone know of a solution to this? it appears to be a headunit problem I plugged in the factory amp and got the same result.

I've heard the LCI professional head unit addresses this issue can anyone confirm?

taibanl · 10-12-2015, 10:15 AM

I have posted a thread on defective hu. Please search (using that term). I am on my iphone else i would link it

ctuna · 10-12-2015, 10:27 AM

http://www.e90post.com/forums/showthread.php?t=1036190

csu87 · 10-12-2015, 11:49 AM

Also check all your grounds. a loose/disconnected ground can do the same thing.

ctuna · 10-12-2015, 01:33 PM

To isolate source inject and audio signal at amp.
If there is not noise with something else driving the amp
then most likely its the radio.

titium · 10-12-2015, 03:52 PM

Thanks guys! Out of warrantee unfortunately....

Where are the ground connections I should check?
Behind the unit itself?

10-12-2015, 05:13 AM	#1
titium Major 327 Rep 960 Posts Drives: 2009 BMW 135i Join Date: Jun 2015 Location: Sydney iTrader: (0)	Audio hiss with professional audio Car is a 2009 135i e82. Experiencing slight hiss with the radio off amplified at low volumes with the radio on. After installing an aftermarket amp if I run any gain the hiss is really loud and annoying. Does anyone know of a solution to this? it appears to be a headunit problem I plugged in the factory amp and got the same result. I've heard the LCI professional head unit addresses this issue can anyone confirm?
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10-12-2015, 10:15 AM	#2
taibanl Brigadier General 281 Rep 4,121 Posts Drives: BMW Join Date: Sep 2010 Location: NA iTrader: (4)	I have posted a thread on defective hu. Please search (using that term). I am on my iphone else i would link it
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10-12-2015, 10:27 AM	#3
ctuna Lieutenant General 1911 Rep 13,103 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	FYI http://www.e90post.com/forums/showthread.php?t=1036190
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10-12-2015, 11:49 AM	#4
csu87 Banned 2134 Rep 3,554 Posts Drives: 09 335xi Join Date: Nov 2013 Location: Northern Colorado iTrader: (0)	Also check all your grounds. a loose/disconnected ground can do the same thing.
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10-12-2015, 01:33 PM	#5
ctuna Lieutenant General 1911 Rep 13,103 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	To isolate source inject and audio signal at amp. To isolate source inject and audio signal at amp. If there is not noise with something else driving the amp then most likely its the radio. Last edited by ctuna; 10-12-2015 at 04:31 PM..
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10-12-2015, 03:52 PM	#6
titium Major 327 Rep 960 Posts Drives: 2009 BMW 135i Join Date: Jun 2015 Location: Sydney iTrader: (0)	Thanks guys! Out of warrantee unfortunately.... Where are the ground connections I should check? Behind the unit itself?
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