Drake02

I had 4 new Rockford Fosgate speakers put in a couple of days ago (2 in the front and 2 in the back) and a 4 channel amp (forgot the name but it's by some off brand that JL Audio makes). I also have an Eclipse 12" sub that was built into my trunk 2 years ago. Anyhow, I didn't drive my car yesterday but this morning I started hearing a whining noise coming from the engine bay. It sounds like a mini supercharger whining under there because it's not very loud- I didn't hear the noise anymore after I turned the radio up. The 4 speakers are running to the amp, I still have the stock Monsoon HU, I have that 12" sub with it's own amp, my dome lights dimmed for a moment when I turned on the defroster, and now there's a whine. Do you all think it might be my battery's life coming to an end or my alternator having problems?

Drake02

By the way... today I noticed that the sounds gets louder as my rpm level goes up.

vjo90rs8

iTrader: (9)

did you run your amplifier power cable along with the speaker wires? The battery and alternator are fine, your speaker wires are picking up noise from your amplifier power cable, that's why it changes with RPM. Do a search, very common problem.

Drake02

I had a stereo shop do the install for me so I will be taking this back to them. I just didn't want to confront them then have it be my alternator or battery not their work.

Also, my radio does not have to be on for me to hear the whine. This morning I actually turned the radio off... this is how I was able to hear it go up and down with the RPM level. I did have my headlights on but why would this noise still happen with the radio off?

Nightrydass

buy a gound loop isolator

vjo90rs8

iTrader: (9)

Is your amplifier turning off when you turn your radio off? Aftermarket head units have remote turn on wires that you run to your amplifier, when the head unit turns on the remote wire goes high and turns on the amp. With a stock monsoon head unit I'm not sure which method they are using to turn on your amp. They could be using an ACC or IGN wire that is HOT when the car is in the ON position so as long as your car is in the ON position or running, the amp is ON. If this is the case, head unit OFF, amp ON, noise injected into the speaker wires and going to the speakers.
Definitely bring it back, you paid for them to do it right

ItsNotStock

iTrader: (24)

+1 Sounds like poor grounds.

Drake02

Thanks for all the info! I will definitely be taking the car back to them today or tomorrow and question them about these issues (poor grounds, poor wiring).

dragonrage

That's uncommon. I'd say rare, even, for that to cause any problem at all. Bad ground is likely.