Gewgaw

Hey all, recently installed a Pioneer AVIC-8000NEX head unit with a NavTV MOST HUR interface going into the existing BOSE amp. I'm getting an high pitched whine/hiss noise that changes pitch with the engine RPMs.

I've read from here and other forums that this most likely is a grounding issue. However, would installing an inline noise filter eliminate this problem at all? Installing an inline filter would be a lot easier than re-grounding everything....

Thanks for any advice!

Jossue

It should help I had the same issue on mine when I installed a dnx771hd. Filter went in, noise stopped

Wayne Smith

Look back to a post from last weekend ... Static.

Gewgaw

Wayne, thanks for the reference. I think my engine whine goes beyond just the cable connecting my phone to the head unit... it happens even when my phone isn't connected, and I'm listening to other sources, or even when the audio is completely turned off. So it must be something happening inside the install....

Gewgaw

I'm glad to hear a filter helped! What filter did you add and where in the circuit did you add it? I'm doing some Google searches and I'm seeing filters that go between the battery and the alternator, filters that go between the RCA inputs, filters that go between the antenna and the head unit....

Also, did you experience any loss of audio quality or volume after adding the filter?

Wayne Smith

The ferrite bead (filter) was to remove the engine noise going to the phone power supply that was then transferring to the outputs. My thought was that if you could do the same for the power source to your radio this might be an easy fix.

Jossue

Mine was from the amp to the battery

Gewgaw

One thought -- since the BOSE operates on (digital) fiber optic lines from the head unit to the amp, as well as from the amp to the speakers, if I'm getting ANY analog type alternator whine in the signal it MUST be coming from the head unit, isn't it?

Petza914

I have a very faint background noise after the stereo install in one of my cars too (not a 997). Does the filter go around the 12v power supply line to the head unit or around the ground wire?

Thanks.

gasongasoff

Alternator whine is OFTEN a grounding issue. Where did you connect the ground of your head unit and the NavTV unit? One thing you can do is double-check that you really sanded the enamel/paint/oxidation off the metal where you bolted your ground connection.

Wayne Smith

Ferrite bead ideally wraps around ground and power supply lines.

Petza914

Thanks Wayne. One on each separately or both wires through the same ferrite bead?

Wayne Smith

One with both wires would be my approach assuming you can do it that way.

memoag12

HELP PLEASE
Everyting works fine BUT, after 10mins aprox the sound is killed and replaced with static noise! very loud static noise, not interference. I already check using other rca source like an ipad and the problem continues. When I turn off the car for 5 mins everything works again but again 10min later it fails.
Any sugguestions?
I am using most hur 997, already update it and I am trying to install Alpine IVA W_200

DC911S

Sounds like something gets hot, and then put out EM noise. Very common in electronics that are going bad. Transistors are funny things sometimes...