Noise coming through speakers - Help Needed - Page 3

muldrick · 09-21-2004, 12:10 PM

I had a lot of different noises. I bought high quality RCA cables and used this (http://www.radioshack.com/product.as...5Fid=274%2D883) from the shack. This way the RCA cables are shielded all the way up to your sound card.
Then I still had an alternator whine. I did this: with the engine running (and noise present) I tried several different ground locations on the truck(from the PSU) until I found a ground where the noise was gone.
Funny thing is, I used an ohm meter and checked the original ground location....:0 ohms, meaning the ground was perfect, but the noise still present. Point is, even thought the ground was good, the computer didn't like that. Don't ask me why. It didn't make sense to me.

tbird2340 · 09-21-2004, 12:27 PM

So you plugged that thing from radio shack directly into the sound card? Also, did you see my cables I have to use.. Do you think they make high quality ones like that?

muldrick · 09-21-2004, 12:34 PM

You're probably ok with them. It's just the first set (1st picture) that needs replaced with high quality/shielded RCA cables and the shack adaptor.
Cables like these:http://www.radioshack.com/product.as...5Fid=15%2D2423
Run some shielding for the other cables that you've got. (wouldn't know what/where to get that)

Do try to run your power wires as far from the RCA's as much as possible.

Then do the ground check while its running with the noise present

SAScooby · 09-21-2004, 12:43 PM

I think your itps connected to the radio might be a contributer to this problem as well, is there a way that you can remove this and test temporarily ?

you can also wrap your power / signal wires in tin foil to create isolation

tbird2340 · 09-21-2004, 03:04 PM

Quote: Originally Posted by SAScooby

I think your itps connected to the radio might be a contributer to this problem as well, is there a way that you can remove this and test temporarily ?

you can also wrap your power / signal wires in tin foil to create isolation

I don't think I can test w/out a remote wire hooked up to the ITPS. I think I'll have to find another switched wire...

Thanks for the advice...

muldrick · 09-21-2004, 06:20 PM

Don't know much about the ITPS. (I probably should be quiet, the way people get slammed on this forum) But if it supplies power to the PSU then I'd agree with SAScooby that it should not come from your HU.
I use an Opus 90W, and my switched source comes from an ignition switch wire.

muldrick · 09-26-2004, 06:55 AM

tbird, did u fix it?

tbird2340 · 09-26-2004, 12:15 PM

I tried moving the remote wire on my ITPS off the headunit and onto another switched wire but that didn't do anything.

I bought a ground loop isolator from walmart and I think it helped. I had to put my stock speakers back in (my Infinity Kappa's were blown) so I have to wait until I get my Infinity's back until I can really tell. The whine is gone in low volumes but if I really crank it up to like 65 (which I usually don't go past 55 on my radio volume) I can hear the whine.

Joe_Collectible · 09-27-2004, 03:27 PM

Quote: Originally Posted by tbird2340

The main problem at this momment is alternator whine. I can hear the whine change as my RPM's go up / down. It's getting to where I can't stand it but need to find time to try something..

I'm going to try a 10AWG ground. Currently I have a VERY thin ground. 18-24AWG. I'm not sure exactly what gauge it is I just had it laying around..

Also, your supposed to run the power/ground as far away as possible from the RCA's but with my setup this isn't realistic. Are there any solutions for this? Can I run one set of the wires in a PVC tube? Would that help?

You Friggin' Nailed it man!

If your RCA's are near your power lines running to amp, you will get noise. 9 times out of 10 this is the case. Run power lines approx 18 inches away (if parallel) from the rca's... It is possible somehow

*Even if the RCA's are high quality shielded (magnetic shield) they can still pick up noise from power cable.

Also remember this: Once you get your power and rca ran totally seperatly, they have to come back together at the amp. You want the power coming in from one side and the rca's coming in from the other.

If your RCA's are crossing over/under the power or even worse, touching the power cable -anywhere- you will most certainly have the symptoms you are describing.

If you turn your volume down and still hear that whizziiiiizzzzzz with engine it is alternator whine

Joe_Collectible · 09-27-2004, 03:31 PM

one more thing... test for whine on interstate/highway, not in driveway. Bad to turn 3500-5000 rpm's on a zero load motor.