Alternator Whine :(

[washdup]

I recently installed an Infinity BassLink in my ‘98 wagon and ever since then I hear a whine coming primarily from the passenger-side speakers. I’d like to get the whine eliminated and am hoping by explaining what I’ve done, step-by-step, maybe you all can help me sort it out.

Going back to the beginning, I started out with an SC-816 stock HU. I first added a T5 40w x 4 amp, mounted behind the HU. I later exchanged the SC-816 for an SC-901 and found it to be a worthwhile upgrade. Next I swapped out the front door/dash component speakers for some Polk coaxials. Also nice. At that point, I wanted to add some bass, so I started shopping for powered subs and settled on an Infinity BassLink. Up to this point, there was no whine anywhere.

I bought an 8-gauge wiring kit and installed the BL right behind the left rear seat, running the power down the driver’s side, under the plastic strips along the kick panels. For ground, I used an existing screw I found below the driver’s side D-pillar speaker (tweeter) way in the back. I bought a wiring harness off of eBay that allowed me to keep my existing 4x40 amp and run switched power and signal via RCA’s out of the back of the amp, without splicing into existing speaker wires. So far, so good.

Then I did something very noobish. Instead of buying extensions for the RCA’s, I thought it would be fun to solder extensions onto them, not realizing that an RCA cable is coaxial and you really cannot solder two RCA’s together because the plastic melts. So that failed and I lost my RCA plugs. I was able to save the day, somewhat, by just separating the two component parts of the coaxial wires and soldering the two copper parts to the 20-gauge speaker wires supplied with the Basslink.

I then ran the speaker wires out the plastic panel under the glove box, down under the carpet, along the left side of the passenger seat until they daylighted under the rear folding seat, as shown in this pic. You can see a tiny bit of the red power wire at the bottom of the photo.

This next photo is a diagram of the wiring runs (power = red, ground = grey, and signal = blue). The speakers with the most interference are indicated in green. Note: as mentioned above, the diagram inaccurately shows the signal wires' location as being by the door; they are actually down the center by the passenger seat.

Finally, the last photo shows the wired-up connections at the BassLink. You can see the pretty-skimpy speaker wires being used to supply signal to the Basslink. At some point, I'll probably trim everything down, but until the whine is sorted out, it's still in "temporary" phase. Now, to repeat, the BL itself has no interference or whine; it’s mostly confined to the right (passenger) side speakers.

Thanks to all who assisted me with the install (see my original thread). I am satisfied with the sound quality of this arrangement, but for the whine.

[850boostin]

Probably has to be an issue with the signal wire. Just try and run a separate RCA from the head unit to the basslink. You can just run it over the seats, if that fixes then obviously hide it. You can get some cheap signal wire from walmart. If that doesnt fix it check your ground wire and make sure its a good ground with the ground touching the chassis and there is not paint in between. I hope this helps, its a little harder to trouble shoot with a factory stereo.

BTW how do you like the basslink?

[BEJinFBK]

Probably has to be an issue with the signal wire. Just try and run a separate RCA from the head unit to the basslink. You can just run it over the seats, if that fixes then obviously hide it. You can get some cheap signal wire from walmart. If that doesnt fix it check your ground wire and make sure its a good ground with the ground touching the chassis and there is not paint in between. I hope this helps, its a little harder to trouble shoot with a factory stereo.

BTW how do you like the basslink?

+1. Ditch the speaker hookup and go RCA from the 901.

And "over the top", temporary RCA hook-up as described above is

an excellent idea for getting to the bottom of your noise problem.

And I'm also curious about the Basslink...

[MyCarIsRed]

+1. Ditch the speaker hookup and go RCA from the 901.

And "over the top", temporary RCA hook-up as described above is

an excellent idea for getting to the bottom of your noise problem.

And I'm also curious about the Basslink...

So you're running the HU rca out into the speaker in on the baslink? mismatched signals there, get rca all the way, and yes you can extend them.

Your ground should be as close as possible to the amp, and as good as possible.

Is the noise linked to rpms?

[washdup]

Thanks for the suggestions. Would the BassLink's speaker wires really throw off interference into the right-side speakers, though? I thought it was only the power lead that does that, but the power wire is on the opposite side of the car from where the interference is heard. I'm not trying to be difficult, just trying to understand it.

The ground is pretty far from the BL. The wire is fully extended (around 3'), but it appears to be a good location. I sanded any paint off before attaching. But again, wouldn't a poor ground from the BL only impact that speaker? There is no whine from the BL itself. Yes, the whine is related to RPMs.

OK, as for the BL itself, I'm surprised at how little "thump" it produces, but that's not what I bought it for. It does a nice job filling in the deepest bass, and it sounds pretty clean. It's pretty large, although smaller and better shaped for wagon use than a Bazooka. I wish there was an easy way to run 6x9s flush-mounted in a wagon.

[mkc70]

Thanks for the suggestions. Would the BassLink's speaker wires really throw off interference into the right-side speakers, though? I thought it was only the power lead that does that, but the power wire is on the opposite side of the car from where the interference is heard. I'm not trying to be difficult, just trying to understand it.

The ground is pretty far from the BL. The wire is fully extended (around 3'), but it appears to be a good location. I sanded any paint off before attaching. But again, wouldn't a poor ground from the BL only impact that speaker? There is no whine from the BL itself. Yes, the whine is related to RPMs.

OK, as for the BL itself, I'm surprised at how little "thump" it produces, but that's not what I bought it for. It does a nice job filling in the deepest bass, and it sounds pretty clean. It's pretty large, although smaller and better shaped for wagon use than a Bazooka. I wish there was an easy way to run 6x9s flush-mounted in a wagon.

Still having issues I see. Start with the simple items.

1. Unplug iPod cable from back of SC-901 and see if noiese disappears.

2. Disconnect Ebay adapter and just go hi-level off the rear speakers.

My money is on the Ebay adapter causing your noise. If you are feeling up to it take it apart and make sure the braided shield is not connected to the metal plug end of the DIN cable. No need for remote turn on since you can set the BL for music sense. Location of your BL could be the reason it sounds weak, most of the time they sound surprisingly well for what it is, GL.

[andyb5]

Hey Mitch, I just installed this filter from David Navone Audio (despite his snobbish answer to your earlier question) between my RCA cables and my amp, and it completely eliminated my alternator whine (ground loop)

I'd give that a try and see if it works for you.

[washdup]

Still having issues I see. Start with the simple items.

1. Unplug iPod cable from back of SC-901 and see if noiese disappears.

2. Disconnect Ebay adapter and just go hi-level off the rear speakers.

My money is on the Ebay adapter causing your noise. If you are feeling up to it take it apart and make sure the braided shield is not connected to the metal plug end of the DIN cable. No need for remote turn on since you can set the BL for music sense. Location of your BL could be the reason it sounds weak, most of the time they sound surprisingly well for what it is, GL.

In writing up my history, I left off the earlier step in the process where I had the BL wired up to receive signal off the rear pillar speakers. Sorry, forgot about that. There was whine with that setup, too, although I'm not sure where it was coming out of. Probably the same as now, although at the time I just assumed it was out of the BL.

Why do you think disconnecting the iPod from the changer input might stop the whine? I'm definitely going to try that, but curious whether there is something you think is up.

As for the adaptor, I would not be surprised if there was an issue with it. I may end up ordering another one with extended RCAs or one with short RCAs and get some female/male extensions to reach up to the BL, just to eliminate that as a possibility as others have suggested, above.

[washdup]

Hey Mitch, I just installed this filter from David Navone Audio (despite his snobbish answer to your earlier question) between my RCA cables and my amp, and it completely eliminated my alternator whine (ground loop)

I'd give that a try and see if it works for you.

Congrats on getting rid of your whine, Andy! Wasn't yours coming out of the sub, though? Do you think a filter in my sub's signal feed would help with whine coming from other speakers?

[MyCarIsRed]

Thanks for the suggestions. Would the BassLink's speaker wires really throw off interference into the right-side speakers, though? I thought it was only the power lead that does that, but the power wire is on the opposite side of the car from where the interference is heard. I'm not trying to be difficult, just trying to understand it.

The ground is pretty far from the BL. The wire is fully extended (around 3'), but it appears to be a good location. I sanded any paint off before attaching. But again, wouldn't a poor ground from the BL only impact that speaker? There is no whine from the BL itself. Yes, the whine is related to RPMs.

OK, as for the BL itself, I'm surprised at how little "thump" it produces, but that's not what I bought it for. It does a nice job filling in the deepest bass, and it sounds pretty clean. It's pretty large, although smaller and better shaped for wagon use than a Bazooka. I wish there was an easy way to run 6x9s flush-mounted in a wagon.

Try swapping the inputs on the basslink and see if the signal switches side. Might be something in there working it's way back up the chain?

3' isn't that bad, 8ga should be ok for that.

I ran a bazooka for years till it finally blew, if you don;t really clamp it to the body of the car you loose tons of bass.

you can always toss a choke coil on the wires too, see if that helps.hurts

[andyb5]

Congrats on getting rid of your whine, Andy! Wasn't yours coming out of the sub, though? Do you think a filter in my sub's signal feed would help with whine coming from other speakers?

Thanks! And actually, my whine was in my front channel. I threw a filter on the rear (sub) channel for good measure, but it wasn't necessary. Now that I think about it, I'm not sure if it will help your setup though

[washdup]

Now that I think about it, I'm not sure if it will help your setup though

I'm not sure anything will help me , but at least I now have a few ideas for troubleshooting. Thanks to all.

[mkc70]

In writing up my history, I left off the earlier step in the process where I had the BL wired up to receive signal off the rear pillar speakers. Sorry, forgot about that. There was whine with that setup, too, although I'm not sure where it was coming out of. Probably the same as now, although at the time I just assumed it was out of the BL

While you did the hi level, did you actually physically disconnect the BL Ebay adapter from the DIN cable? Or were you under the impression that just because the signal to the BL was coming from the speaker wires the setup was changed? This is an assumption since you made no mention of a remote turn on wire added, or reinstalling the loop for signal sensing ability.

The SC-901 is a nice stock radio, but it is easily susceptible to noise problems with certain setups.

[washdup]

It's embarrassing, but I'm not positive. At first I wanted to say the eBay harness was not in, but then I remembered it was in place while I was using input from the rear tweeter signal wires because at the time I was unsure whether the auto-turn-on function was working with that setup, and I wanted to at least have use of the direct switching function from the harness. I also forgot to mention that I've have had the black remote gain knob just left of the shifter on the side of the drive train mound since the beginning, FWIW.

[MyCarIsRed]

It's embarrassing, but I'm not positive. At first I wanted to say the eBay harness was not in, but then I remembered it was in place while I was using input from the rear tweeter signal wires because at the time I was unsure whether the auto-turn-on function was working with that setup, and I wanted to at least have use of the direct switching function from the harness. I also forgot to mention that I've have had the black remote gain knob just left of the shifter on the side of the drive train mound since the beginning, FWIW.

My gain was mounted in the little switch blank opposite the trans switch, raw, no box or nothing. trimmed it down to fit. Never had an issue.