SOLVED: Alternator whine in RF channel only

[bmwman91]

Yo dawg, I heard you like to twist...

[modernist]

I think I went overkill, though. I twisted everything I could find, then I twisted the twisted stuff together. Worked, though.

[modernist]

They did! I'm thrilled. Jammed all the way to Ann Arbor today. Fucking dope sound.

[StereoInstaller1]

Ha, no shit....twisted wires fixed it?

You, Sir, are a fucking genius!

Luke

[ELVA164]

This is why I like wandering around this forum sometimes. I learn cool stuff like this!

[bmwman91]

Lessons learned: Mother nature thinks everything is an antenna.

Ha. I know electrical engineers that hadn't figured that out even after 4 years of college. Glad things worked out for you.

[modernist]

If it works, it works. If Luke uses it, it's gotta be good.

If anyone is curious, here's a diagram of the completed system.

[Ray Smoodiver]

Inb4 Luke says that's how he does all his wiring ;)


(But seriously, that's how he does all his wiring).

[modernist]

Yup, sure did. Jammed one end of the wires in a door, went to town with the drill. Used the twisted cable for both fronts.

It worked! Thanks for helping a noob out. Whine is 100% gone.

Lessons learned: Mother nature thinks everything is an antenna. Twisted pairs are magical. Never cut corners.

[bmwman91]

Good luck. Looks like you gave your drill a workout! (that's how I twist wires anyway)

[modernist]

Hope this works.

[modernist]

That makes sense. I have an early non-premium car, so it had the fader in the dash and common ground spliced under the carpet. The wiring to the back is totally stock, which would explain why there's no noise back there. The front positives are from the factory loom, while the negatives are new. They are not close together, nor are they twisted together. I'll try running new front positives as well, and twisting them to the new negatives.

The noise is in both the mid and the tweeter. It's still present with the tweeter disconnected. The noise is only present when the car is running; in ACC with the car off, sounds great. No distortion, has a warm, detailed sound.

[bmwman91]

Are the new RF wires a tightly twisted pair, or are they separate/parallel? The stock wires are twisted together for a reason...when interference is induced by stuff like adjacent power wiring with large transient currents, the twisted pair of wires will pick up the interference equally (or closely anyway) which effectively cancels it out. If you pulled that wiring out and put in new separate wires then yes, it is possible that there is interference from the big power wire loom on the right side of the car. It sounds like you probably had to replace all of the speaker wires when you changed over to powering the speakers from the head unit?

The only other thing I can think of is that a capacitor in the crossover is crapping out and causing some serious distortion. Is the noise you hear coming from both the mid and tweeter or just the tweeter?

[modernist]

Would grounding the chassis of the head unit itself do anything? Would the main power line running near the RF speaker cause interference? I only ran into this after I converted it to a 4-channel floating ground system from a 2-channel common ground system. Literally only ran two wires, RF – and LF –. At my wits end.

Another theory: the crossover attached to the premium sound mid is picking up interference. Thoughts?

HELP

[modernist]

Made a ground strap for the hood, put it on. Removed everything from g200, cleaned it up with a file. Reattached. Ran a brand new - cable on the right side, redid all splices. No change.