Engine whine - Desperately need help

[EmpiricalApe]

I've posted about this topic a couple times already, but I have yet to find a solution. I installed an after market amplifier to power my mids and highs. I already have a sub amp that isn't having the same issues. My stereo is a JVC KW-M780BT. The amplifier powering the whine is a Infinity REF-3004A. I get slight buzz in my speakers with the engine off, and a complete whine that goes with rpms when the engine is on. I have tried running different RCAs in different locations, running power wire in different locations, I've tried different speakers, I've tried different ground points, I've tried grounding the stereo at the same point as the amplifier. I'm running crutchfield 8 gauge ofc power and grounds, and stinger 14 gauge ofc speaker wire, and crutchfield higher end 4 CH RCAs. I've started an exchange with crutchfield for the stereo, and tried the same model but different unit. I've put an inline noise filter on the stereo power wire, and I have a PAC SN1 2-CH Ground loop isolator for all 4 RCAs. I have all speakers but front right put in because I just haven't gotten to it if that may cause something somehow. I've connected my phone to the amp, still ran off of the cars power, and it was perfect audio...no buzz, no whine, no static. I greatly appreciate any help. I am at my wits end. Thank you.

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[JohnPD]

I've posted about this topic a couple times already, but I have yet to find a solution. I installed an after market amplifier to power my mids and highs. I already have a sub amp that isn't having the same issues. My stereo is a JVC KW-M780BT. The amplifier powering the whine is a Infinity REF-3004A. I get slight buzz in my speakers with the engine off, and a complete whine that goes with rpms when the engine is on. I have tried running different RCAs in different locations, running power wire in different locations, I've tried different speakers, I've tried different ground points, I've tried grounding the stereo at the same point as the amplifier. I'm running crutchfield 8 gauge ofc power and grounds, and stinger 14 gauge ofc speaker wire, and crutchfield higher end 4 CH RCAs. I've started an exchange with crutchfield for the stereo, and tried the same model but different unit. I've put an inline noise filter on the stereo power wire, and I have a PAC SN1 2-CH Ground loop isolator for all 4 RCAs. I have all speakers but front right put in because I just haven't gotten to it if that may cause something somehow. I've connected my phone to the amp, still ran off of the cars power, and it was perfect audio...no buzz, no whine, no static. I greatly appreciate any help. I am at my wits end. Thank you.

You might have to take it to an audio shop and have them troubleshoot it, you have a grounding issue somewhere in your vehicle. Are you certain your alternator is good? You might have a bad winding in it.

 

[Doxquzme Premium Member]

I've posted about this topic a couple times already, but I have yet to find a solution. I installed an after market amplifier to power my mids and highs. I already have a sub amp that isn't having the same issues. My stereo is a JVC KW-M780BT. The amplifier powering the whine is a Infinity REF-3004A. I get slight buzz in my speakers with the engine off, and a complete whine that goes with rpms when the engine is on. I have tried running different RCAs in different locations, running power wire in different locations, I've tried different speakers, I've tried different ground points, I've tried grounding the stereo at the same point as the amplifier. I'm running crutchfield 8 gauge ofc power and grounds, and stinger 14 gauge ofc speaker wire, and crutchfield higher end 4 CH RCAs. I've started an exchange with crutchfield for the stereo, and tried the same model but different unit. I've put an inline noise filter on the stereo power wire, and I have a PAC SN1 2-CH Ground loop isolator for all 4 RCAs. I have all speakers but front right put in because I just haven't gotten to it if that may cause something somehow. I've connected my phone to the amp, still ran off of the cars power, and it was perfect audio...no buzz, no whine, no static. I greatly appreciate any help. I am at my wits end. Thank you.

You really should wait until you have the replacement HU. Your previous thread pretty much exhausted any other part of the systems as being the culprit. The fact that you were able to get it to play fine when hooked up to a neutral source through the existing wiring and amps points directly to the HU as the source. Just make sure when you get the new HU that you ground it directly into the metal in the dash, should be a point right behind that you can use or create a grounding point. Make wure to take a little sandpaper to the area you are going to use, hopefully that takes care of the issue.

 

[EmpiricalApe]

You really should wait until you have the replacement HU. Your previous thread pretty much exhausted any other part of the systems as being the culprit. The fact that you were able to get it to play fine when hooked up to a neutral source through the existing wiring and amps points directly to the HU as the source. Just make sure when you get the new HU that you ground it directly into the metal in the dash, should be a point right behind that you can use or create a grounding point. Make wure to take a little sandpaper to the area you are going to use, hopefully that takes care of the issue.

I wasn't too clear in the post, but I did recieve the new headunit and grounded it to the frame behind the stereo and it was the exact same.

 

[Doxquzme Premium Member]

I wasn't too clear in the post, but I did recieve the new headunit and grounded it to the frame behind the stereo and it was the exact same.

Yikes, time to replace the car.! Jk... I would take it to a (reputable) shop and see if they can't isolate it for you. I mean, there is something getting in the signal path. The fact that you were able to play it without any noise means that something from behind the dash or along the path of the RCA's (assuming path was different when testing with the phone). It works fine until the signal RCA's that run their path up under the dash back to the HU would be the only difference.

 

[1aespinoza 10+ year member]

I wasn't too clear in the post, but I did recieve the new headunit and grounded it to the frame behind the stereo and it was the exact same.

This may be unorthodox but... try using an LOC with the high speaker output.

 

[Doxquzme Premium Member]

This may be unorthodox but... try using an LOC with the high speaker output.

There's a thought...

 

[Jimi77 5,000+ posts]

To fix whine:

Replace RCA's with shielded RCA (usually the cheaper RCAs)
Run a ~16awg between HU ground and amp ground
Of course make sure you have a solid ground at the amp. Ground to the battery/block if necessary.
Ground Loop isolator as a last resort.

 

[HardofWhoring]

If you just swap RCA's at the amp, you can figure out if its the head units channel or RCAs, or if it's the amp and the amps ground.

There's no reason you can't take the amp out, wire it short to the battery, and as close to chassis ground, as you can get if you can find a good obvious ground.


Something I have found before: Your head unit's wiring might not work for the cradle/head unit space. I have found with a vehicle before that once a head unit was mounted, the bracket behind the head unit was putting pressure on the RCA cable plug behind the new head unit. That was causing resistance and a ground loop. Take the head unit out of the mount, and sit it somewhere so that none of the wires have pressure on them. If you haven't isolated it yet, that RCA cable might be making contact with a bracket or something else behind the head unit that's giving it a slight bend and resistance. We actually had to switch to a different head unit because of what side the RCA plugs were on.

 

[EmpiricalApe]

If you just swap RCA's at the amp, you can figure out if its the head units channel or RCAs, or if it's the amp and the amps ground.

There's no reason you can't take the amp out, wire it short to the battery, and as close to chassis ground, as you can get if you can find a good obvious ground.


Something I have found before: Your head unit's wiring might not work for the cradle/head unit space. I have found with a vehicle before that once a head unit was mounted, the bracket behind the head unit was putting pressure on the RCA cable plug behind the new head unit. That was causing resistance and a ground loop. Take the head unit out of the mount, and sit it somewhere so that none of the wires have pressure on them. If you haven't isolated it yet, that RCA cable might be making contact with a bracket or something else behind the head unit that's giving it a slight bend and resistance. We actually had to switch to a different head unit because of what side the RCA plugs were on.

fortunately, this stereo has a very shallow chassis. Most of my testing has been done with stereo sitting outside of the mounting area, with little to no stress on the wires.

 

[EmpiricalApe]

To fix whine:

Replace RCA's with shielded RCA (usually the cheaper RCAs)
Run a ~16awg between HU ground and amp ground
Of course make sure you have a solid ground at the amp. Ground to the battery/block if necessary.
Ground Loop isolator as a last resort.

Currently, I have the mids amp and the headunit temporarily grounded directly to the negative terminal on the battery. I also have an in-line noise filter on the stereo power wire. I also have a ground loop isolater on the rcas for my sub amp (that worked better than putting ground loop isolators on all 4 mid amp rcas). Having three ground loop iso on the sub rcas made the amp pull significantly less power. The whine seemed to actually get worse after grounding the amp and stereo to the battery. Any more ideas?

 

[Jimi77 5,000+ posts]

Currently, I have the mids amp and the headunit temporarily grounded directly to the negative terminal on the battery. I also have an in-line noise filter on the stereo power wire. I also have a ground loop isolater on the rcas for my sub amp (that worked better than putting ground loop isolators on all 4 mid amp rcas). Having three ground loop iso on the sub rcas made the amp pull significantly less power. The whine seemed to actually get worse after grounding the amp and stereo to the battery. Any more ideas?

Disconnect power from the sub amp system (the RCAs and the ground). See if that eliminates the ground loop.

 

[EmpiricalApe]

Disconnect power from the sub amp system (the RCAs and the ground). See if that eliminates the ground loop.

it did not, I already tried that I believe but I'll double check.

 

[EmpiricalApe]

Disconnect power from the sub amp system (the RCAs and the ground). See if that eliminates the ground loop.

yeah I disconnected the ground, rcas, and remote wire of the sub amp there's no change