Issue with adding second amp

andyhbmw · 11-13-2014, 04:13 PM

I have a 2011 328i xdrive with the base hi-fi system (i think that's what it's called -- it has mid, and tweeters in the front, subs under the front seat, mids in the rear deck, and an amp in the back.) I had a second amp added to power the mids and tweets. Stock amp still powers the subs. The problem is that the new amp powers off when I turn off the engine with a single push of the start/stop button. The head unit stays on, and the other amp stays on (as they should). Obviously something isn't wired correctly. Is there an easy way to describe how to do it correctly, so the new amps stays on the same as the rest of the system. I have read a ton of information on here and I'm pretty sure there are some posts that touch on this, but I just don't fully understand what is happening. Any info that I could pass on to my installer would be greatly appreciated.

terminator2k2 · 11-13-2014, 04:25 PM

All that is happening is your remote or control wire for the new amp is wired from the ignition, where as the stock amp is possibly using audio sensing to turn that amp on or off....just how mine is wired. Only my second amp is for the subwoofer in the boot. All I lose when I turn off the engine is the sub which I'm ok with that as it won't flatten the battery when I'm sitting in the car.

Without starting the car again try pressing the start button.

andyhbmw · 11-13-2014, 09:52 PM

Thanks for the reply terminator2k2. Is it possible to wire my second amp the same way as the stock amp? When I turn off the engine I lose everything except for the sub, so basically I can't hear anything except bass. By cycling through the start button, I can get it back on without starting the car, but that is less than ideal.

terminator2k2 · 11-14-2014, 02:41 AM

Give technic a shout , I'm sure he does a harness for stuff like this. Tell him what your after and see what he says.

andyhbmw · 11-14-2014, 08:24 AM

Will do, thanks!

kaigoss69 · 11-14-2014, 08:50 AM

This is what happens when incompetent shops work on BMWs. There are basically two ways to keep the amp on as long as the OEM amp:

1. On the back of the HU there is remote out pin #13. Run that to the amp and the problem is solved.

2. Use a Line Output Converter (LOC) with remote sensing capabilities between the outputs of the OEM amp and the aftermarket amp.

andyhbmw · 11-14-2014, 03:48 PM

Thanks so much kaigoss69! My installer added the Line Output Converter and now the 2nd amp behaves like the factory amp!

11-13-2014, 04:13 PM	#1
andyhbmw Registered 0 Rep 4 Posts Drives: 2011 BMW 328i xdrive Join Date: Nov 2014 Location: Canada iTrader: (0)	Issue with adding second amp I have a 2011 328i xdrive with the base hi-fi system (i think that's what it's called -- it has mid, and tweeters in the front, subs under the front seat, mids in the rear deck, and an amp in the back.) I had a second amp added to power the mids and tweets. Stock amp still powers the subs. The problem is that the new amp powers off when I turn off the engine with a single push of the start/stop button. The head unit stays on, and the other amp stays on (as they should). Obviously something isn't wired correctly. Is there an easy way to describe how to do it correctly, so the new amps stays on the same as the rest of the system. I have read a ton of information on here and I'm pretty sure there are some posts that touch on this, but I just don't fully understand what is happening. Any info that I could pass on to my installer would be greatly appreciated.
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11-13-2014, 04:25 PM	#2
terminator2k2 First Lieutenant 17 Rep 320 Posts Drives: 2006 e90 Join Date: Jun 2012 Location: uk iTrader: (1)	All that is happening is your remote or control wire for the new amp is wired from the ignition, where as the stock amp is possibly using audio sensing to turn that amp on or off....just how mine is wired. Only my second amp is for the subwoofer in the boot. All I lose when I turn off the engine is the sub which I'm ok with that as it won't flatten the battery when I'm sitting in the car. Without starting the car again try pressing the start button. Last edited by terminator2k2; 11-13-2014 at 04:39 PM..
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11-13-2014, 09:52 PM	#3
andyhbmw Registered 0 Rep 4 Posts Drives: 2011 BMW 328i xdrive Join Date: Nov 2014 Location: Canada iTrader: (0)	Thanks for the reply terminator2k2. Is it possible to wire my second amp the same way as the stock amp? When I turn off the engine I lose everything except for the sub, so basically I can't hear anything except bass. By cycling through the start button, I can get it back on without starting the car, but that is less than ideal.
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11-14-2014, 02:41 AM	#4
terminator2k2 First Lieutenant 17 Rep 320 Posts Drives: 2006 e90 Join Date: Jun 2012 Location: uk iTrader: (1)	Give technic a shout , I'm sure he does a harness for stuff like this. Tell him what your after and see what he says.
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11-14-2014, 08:24 AM	#5
andyhbmw Registered 0 Rep 4 Posts Drives: 2011 BMW 328i xdrive Join Date: Nov 2014 Location: Canada iTrader: (0)	Will do, thanks!
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11-14-2014, 08:50 AM	#6
kaigoss69 Brigadier General 300 Rep 3,969 Posts Drives: '08 335i Join Date: Jul 2008 Location: JAX iTrader: (6)	This is what happens when incompetent shops work on BMWs. There are basically two ways to keep the amp on as long as the OEM amp: 1. On the back of the HU there is remote out pin #13. Run that to the amp and the problem is solved. 2. Use a Line Output Converter (LOC) with remote sensing capabilities between the outputs of the OEM amp and the aftermarket amp. __________________ Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa OT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
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11-14-2014, 03:48 PM	#7
andyhbmw Registered 0 Rep 4 Posts Drives: 2011 BMW 328i xdrive Join Date: Nov 2014 Location: Canada iTrader: (0)	Thanks so much kaigoss69! My installer added the Line Output Converter and now the 2nd amp behaves like the factory amp! Last edited by andyhbmw; 11-30-2014 at 03:47 PM..
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