Alternator noise with PDX-5

GtiGyver · 11-08-2009, 10:47 PM

Hi everyone,
I'm having major problems with alternator noise following the install of my PDX-5 amp in the trunk.
In order to isolate the source of the noise I tried running the amp with nothing connected to its inputs and still had the alternator whine.

I also noticed that the whine gets MUCH worse when I drive the car hard.

Has anyone solved this issue? How?

JMH1983 · 11-08-2009, 11:34 PM

Quote:

Originally Posted by GtiGyver

Hi everyone,
I'm having major problems with alternator noise following the install of my PDX-5 amp in the trunk.
In order to isolate the source of the noise I tried running the amp with nothing connected to its inputs and still had the alternator whine.

I also noticed that the whine gets MUCH worse when I drive the car hard.

Has anyone solved this issue? How?

I have seen a few threads on this issue, last one i can remember was buy year1one ? or someone similar to that on his SWS install and the pdx he used. He had a lot of alternator whine, but managed to at least reduce it to a lower level however not remove it compeltely. Others have stated the PDX-5 is a "noisy" amp, and i must admit this scared me off it, so i bought a A JL Audio HD900/5. Maybe send a PM to Technic, he seems to know a lot about this.

Good Luck

mangotangoe · 11-09-2009, 07:30 AM

I currently have two PDX amps installed in my car. The only way I found to eliminate my alternator whine, was to use the factory ground, left side of trunk, fender liner. All other locations incl. battery ground induced noise. It can be very frustrating...

GtiGyver · 11-09-2009, 10:12 AM

I have to admit that I really thought the PDX line of amps would bu much worse for noise from what everyone is saying but TBH when the engine is off, the amps are actually nearly silent.
I'll look into maybe the line from the battery having noise from the alternator due to the way BMW uses "Energy Regeneration". I'm getting the impression that the way BMW unloads the alternator when driving the car hard is by using a high frequency switching circuit and thus producing plenty of noise.

Technic · 11-09-2009, 07:51 PM

Quote:

Originally Posted by GtiGyver

I have to admit that I really thought the PDX line of amps would bu much worse for noise from what everyone is saying but TBH when the engine is off, the amps are actually nearly silent.
I'll look into maybe the line from the battery having noise from the alternator due to the way BMW uses "Energy Regeneration". I'm getting the impression that the way BMW unloads the alternator when driving the car hard is by using a high frequency switching circuit and thus producing plenty of noise.

Could be possible.

Where's your ground point and the 12V?

GtiGyver · 11-09-2009, 10:06 PM

I use a grounding point on the right side (passenger) of the trunk on the wheel well, similar to the one on the other side to which the OEM amp was connected; as for the 12v, I use the point next to the battery to which the largest gauge wire is connected.

11-08-2009, 10:47 PM	#1
GtiGyver Lieutenant 69 Rep 460 Posts Drives: 2009 Space Grey E90 328i MT Join Date: Jun 2009 Location: Montreal iTrader: (3)	Alternator noise with PDX-5 Hi everyone, I'm having major problems with alternator noise following the install of my PDX-5 amp in the trunk. In order to isolate the source of the noise I tried running the amp with nothing connected to its inputs and still had the alternator whine. I also noticed that the whine gets MUCH worse when I drive the car hard. Has anyone solved this issue? How?
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11-09-2009, 07:30 AM	#3
mangotangoe Private First Class 14 Rep 123 Posts Drives: 1M Join Date: Apr 2009 Location: Canada iTrader: (2)	I currently have two PDX amps installed in my car. The only way I found to eliminate my alternator whine, was to use the factory ground, left side of trunk, fender liner. All other locations incl. battery ground induced noise. It can be very frustrating... __________________
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11-09-2009, 10:12 AM	#4
GtiGyver Lieutenant 69 Rep 460 Posts Drives: 2009 Space Grey E90 328i MT Join Date: Jun 2009 Location: Montreal iTrader: (3)	I have to admit that I really thought the PDX line of amps would bu much worse for noise from what everyone is saying but TBH when the engine is off, the amps are actually nearly silent. I'll look into maybe the line from the battery having noise from the alternator due to the way BMW uses "Energy Regeneration". I'm getting the impression that the way BMW unloads the alternator when driving the car hard is by using a high frequency switching circuit and thus producing plenty of noise.
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11-09-2009, 10:06 PM	#6
GtiGyver Lieutenant 69 Rep 460 Posts Drives: 2009 Space Grey E90 328i MT Join Date: Jun 2009 Location: Montreal iTrader: (3)	I use a grounding point on the right side (passenger) of the trunk on the wheel well, similar to the one on the other side to which the OEM amp was connected; as for the 12v, I use the point next to the battery to which the largest gauge wire is connected.
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