I posted over in the Installation Notes section here, but didn't mention my problems.

First, there is engine noise. Second, with the engine off, I still have feedback. My guess is it has something to do with the empeg's outputs being 4V; I don't think the AUX IN of the cd player can handle that (especially when they've all been merged to connect to a single 1/8" stereo plug).

Keep in mind this is temporary. Not too far in the future there will be a new cd player, and an amplifier. If I can solve these problems easily; great. If not, I'll just keep the volume down until I have the new components.

Do not merge the outputs. Use only the front outputs from the empeg into the aux-in of the CD player. The front and rear outputs of the empeg will sound identical when the fader is centered, you don't need to merge anything. Just use the front outputs.

It's unlikely to be caused by the 4v outputs. FAQ entry on 4v outputs is here.

Read through the rest of the FAQ entries in that section about ground loops. Also keep in mind that when you use the CD player's aux-in, you are supposed to have the empeg turned up relatively high (maybe even all the way up to 0db) and then use the CD player's volume to control the overall output.

If you have the empeg turned down really low, but the CD player volume cranked, that might be why you're hearing noise in the system.

you can try your best to keep the 1) power and 2) switched power wires as isolated from the rest of the wires as much as possible.

I had the volume at 0db, and I had already tried using only the front or rear outputs instead of all 4. When using all, more feedback is noticeable. When using only 2, there is less, but not much less.

Also, I believe this feedback is separate from the noise that I'm hearing when the engine is running. The hookups mentioned above were done with the engine off.

When the engine is on, there is also a noticeable whine that changes pitch with the engine's rev. But this is not noticeable until the cd player's volume is turned up to a certain level.

What do you mean by feedback, exactly? Feedback to me means that output from the speakers is getting picked up by a microphone and "feeding back" into the signal to create an infinite loop of screeching. Seeing as I don't think you've got the microphone hooked up...

If you're experiencing distortion, try turning the empeg volume down which at some point will make the 4v outputs into 1v outputs that your cd player is expecting...

Is the engine noise(pitch goes up with acceleration) you're hearing the same when you're listening to a CD and when you're listening to the empeg? Is it empeg only? If it's empeg only, check the empeg's ground, then try connecting the sled to ground also... Do a search for boxter installs, as they're the ones who usualy deal with engine noise coming from the empeg...

Matthew

I this kind of a conversation, usually when someone says "feedback", they are trying to describe the kinds of noises you hear when you have a ground loop.

I agree that the term "feedback" is incorrect in this case. But often they don't know what other word to use.

Yes, I realize now that I am dealing with a ground loop. I apologize for not looking it up first so that I would know the correct term and not have wasted your time.

Matthew, changing the volume on the empeg does not affect the distortion I'm hearing.

And yes, the distortion only happens when the CD player is in AUX IN mode, which means it's empeg only. AM/FM and CD all sound normal.

I believe the source of the problem to be that the wiring harness I scrounged up for the empeg did not actually have a ground wire, and so I had to send the empeg's ground elsewhere (specifically to the ground on the CD player's harness).

This will be rectified as soon as I can find a new Honda standard wiring harness. And while I'm in the dash again, I also plan to reroute the RCA cables coming from the empeg, as they appear to be pinched between the CD player and unkown innards of the car. Just to be safe.

Thanks for your help, guys. I should be able to let you know by tomorrow how things worked out.

If you don't know what the problem is, there's no way to know what it's called, so don't feel bad...

Anyways, ground loops are a pain... While you're in the dash, grab a piece of wire and try connecting the sled to the frame of the car and see if that changes the noise...

Matthew

For me, grounding the player's RCA removes what appears to be a very similiar ground loop problem. To summarise my findings on what appears to be a correct install, I need to apply a good ground to the outer shroud of the player's RCA to remove the background noise (or whine while the engine is running).

Now that I understand the problem, I realize how much of a pain it can be. On the list of things to do - 1) Replace the scrounged wiring harness with a fresh one that includes a ground wire. 2) Reroute the RCA cables through the dashboard so they don't get pinched. 3) Ground the empeg's sled.

For #3, I have a question. Would the sled be sufficiently grounded if the back were mounted to the frame of the car using the strip of metal originally meant to mount the CD player?

Thanks, Rue. If the steps I've outlined don't take care of it, then I'm sure the other methods outlined in that thread will help.

Would the sled be sufficiently grounded if the back were mounted to the frame of the car using the strip of metal originally meant to mount the CD player?

Depends on that particular piece of car frame on your particular car. Some of the sub-frame pieces of the dashboard are not well grounded on some cars.

Grounding the sled should, in theory, be no different than properly attaching the harness ground wire. However, some have reported fixing ground loops by doing precisely that, so have a ball.

Well, I got it. It's not 100%, but it's better than good enough. All that is remaining is a very slight "alternator whine" which is quite acceptable. And by acceptable I mean that on the CD player's volume scale of 0 - 80, the alternator whine cannot be heard below 70, and I never go past 65.

A more professional ground of the sled should finish the job, but that will wait until after the car has had some minor work done.

I performed each of the 3 steps that I outlined yesterday, so either one or all three in combination did the job. I feel so much better.

Again, thanks for help and suggestions, everyone.