Ground loop noise? Or maybe something else...

After much screaming, several bugs, broken nails, cuts and burns, the empeg is finally in my car. And it's so god damn sweet I'm about to go for a drive just to play with it, since it's finally in after a few months. I however have one problem left that I don't know how to fix (and a few minor ones I do). When I turn on the empeg (or the sony head unit that was previously in the dash while waiting for new wires) I get some extremely loud and piercing noise that slowly fades off after about a minute. Went through the crutchfield noise flow chart, first alone, then over the phone with support. They think the amp is defective, as the noise does not come through constantly as it often does with grounding issues. Anyone ever seen this before? Three car audio places have not. Tried adjusting the gains, no change at all. I would really hate to drive in silence while I wait for the amps replacement, and want to avoid more BS with broken bits and pieces (some larger force really does NOT want me to have this thing).

Does the loud-noise-that-fades-out happen when the RCA's are disconnected from the amplifier?

If so, that would also lend credence to the "faulty amplifier" theory. The only other thing I can think of is something really screwy with the wiring, like the headlight illumination wire plugged into the amp remote line or something like that.

But you're right in that most kinds of ground loop noise would simply stay constant with the engine running, and the "fades out after a minute" would make it sound like it's not a ground loop issue.

Except for one particular situation where I know the empeg will make a high pitched whine. That's if you are listening to the AM radio on a certain frequency. My tuner module makes a high pitched whine on a certain AM radio frequency when the unit is cold. As the unit warms up, the whine goes away. I even made Hugo personally witness this one, just to get corroboration. But I don't think this is what you're talking about, right?

Wow, sounds like you have gone through a lot of trouble. Does this sound only happen when you first start the car? What if you put the empeg in and booted it up after the car has been running for a few min already? If theres no difference, it sounds like a bad amp is a reasonable bet.

Sean

Rush deliver the mofo and get it replaced... QUICK YOUR EMPEG AWAITS! It really sounds like its your amps. Try this though... unplug the inputs (rca's) going into you amp but leave the power wires on. Do you still get the same noise? if so its most likely your amps. If not then you've go to look elsewhere.

-Greg

Doh!. I didnt see that anyone else had posted.. ohh well.. let us know whats up.

-Greg

Could this be alternator whine? I'm not really sure what that sounds like though. Try turning your stereo on without the engine running - if the noise isn't there, then it might be alternator related. If it's still there, then it's not.

Now that I think about it, another thing that might cause that kind of noise is some kind of a fault in the wiring that runs to the speakers. For instance, the speakers accidentally getting wired as if they were bridged across channels that weren't meant to be bridged, or if one of the speaker wires contacted a ground or a power source, or something strange like that...

Does the loud-noise-that-fades-out happen when the RCA's are disconnected from the amplifier?

That would be step one in the Crutchfield noise diagnosing flow chart that the FAQ links to. Yes I did.

Except for one particular situation where I know the empeg will make a high pitched whine. That's if you are listening to the AM radio on a certain frequency. My tuner module makes a high pitched whine on a certain AM radio frequency when the unit is cold. As the unit warms up, the whine goes away. I even made Hugo personally witness this one, just to get corroboration. But I don't think this is what you're talking about, right?

Nope, tuner is currenty working just fine, after a wire came out of harness #2 (like I said, greater forces seem to be working against me having an empeg, even more so than my posessed little car) which I managed to fix without any soddering.

Speaking of the tuner, I would like a pointer to some sort of tuner FAQ that can show me how to set up presets and stuff of that sort.

Now that I think about it, another thing that might cause that kind of noise is some kind of a fault in the wiring that runs to the speakers. For instance, the speakers accidentally getting wired as if they were bridged across channels that weren't meant to be bridged, or if one of the speaker wires contacted a ground or a power source, or something strange like that...

Nope, even went so far as to wire a completely different speaker with a new wire that was not attached to the car and got the same screeching. Now I'm really pissed that I have to dismantle this thing and endure silence for a while, unless I go with my friends scamming best buy idea.

Wow, sounds like you have gone through a lot of trouble. Does this sound only happen when you first start the car? What if you put the empeg in and booted it up after the car has been running for a few min already?


It hasn't quite been a complete horror show, but close. This is where it becomes really f***ing insulting. With the exception of the speakers, there has been some sort of defect with everything related to this thing. The so called EZ fit speakers that didn't fit without fairly extensive modification (to be expected, I drive a VW), a really nice burn in the shape of my soldering irons tip on my forearm, a few loose diamonds from my bracelet in my dashboard and a huge gauge in my watch (my own fault). I became convinced it was me towards the end, so I took it to an installer to get the amp mounted, fearing I would shatter my rear window (not wanting to shell out the $6000 for a new top since it can't be replaced independently), and one of the first things I watched him to was whack his head really hard on the trunk lid. I swear I got the one with the hex on it.

And it happens as soon as the head unit is turned on, with both the sony and the empeg.

I swear I got the one with the hex on it.

Dunno, all that stuff sounds like "par for the course" in most D-I-Y car stereo installations. In fact, I've gotten to the point where I consider it a bad omen if I don't injure myself in the process somehow.

I mean, it's always something. Either you don't have the right plug or part for something and you need to rush to Radio Shack with your car half-dismantled, or you slip and give yourself a nasty cut while trying to pry off an interior panel, or you burn yourself with the soldering iron (don't feel bad, I still do that with alarming regularity and I've been doing it for years).

Can I get an amen, people?

And it sounds like the noise thing might in fact be a faulty amplifier, so you can't blame that on a curse. However, I would triple-check all wiring running to the amp, especially power wiring and fuses, just in case.

And what were you doing wearing a diamond bracelet while installing a stereo?

And it happens as soon as the head unit is turned on, with both the sony and the empeg.

Hmmm... you didn't mention a second head unit at first. How are the power and amplifier signal wires connected in this two-stereo arrangement?

Oh, and this amp is under warranty, right? Where did it come from?

I mean, it's always something. Either you don't have the right plug or part for something and you need to rush to Radio Shack with your car half-dismantled, or you slip and give yourself a nasty cut while trying to pry off an interior panel, or you burn yourself with the soldering iron (don't feel bad, I still do that with alarming regularity and I've been doing it for years).

I never had any of these sorts of issues, but then again, according to my friend, the way I had everything laid out on the table in the garage the night before, perfectly organized, double checked to make sure I have one of everything, and extras of some that I might break, reminded him of the old cooking with the anal retentive chef skits on SNL. I've done enough speaker jobs on A3 VW's that getting a door panel off requires about as much thought as farting. And the soldering iron burn is not the usually tiny ones I've given myself and expected, it's large enough to measure up nicely with the entire length of the hot part, both bars of it.

And what were you doing wearing a diamond bracelet while installing a stereo?

I've seldom taken it off in the past 10 years, feel kinda naked without it. Torneau was quite nice about the damage to the watch (they just handed me a new one when I inquired about getting it fixed) and those nice NYC potholes rattled out the missing pieces of the bracelet from the dash.

Hmmm... you didn't mention a second head unit at first. How are the power and amplifier signal wires connected in this two-stereo arrangement?

It is not a two head unit setup. After the wires came out of the sled, I just continued on with the amp and speakers and put the sony back in in a half assed manner until new wires showed up, then removed it again.

Oh, and this amp is under warranty, right? Where did it come from?

Crutchfield. And they're taking it back. Working on a way to get a temp for the next week or so.

Crutchfield. And they're taking it back.

Ah, good. I kinda guessed that since you said you were on the telephone with them about it. They're really good about that sort of thing, which is why I like to deal with them as often as I can.

Hope the soldering iron burn doesn't leave a scar.

"The so called EZ fit speakers that didn't fit without fairly extensive modification (to be expected, I drive a VW)"

Ive had the same problems with speakers, just because they are supposed to physically fit doesn't mean I wont have to drill a bunch of new holes in my metalwork to mount them. :-( I hope the burn heals up ok, I have always avoided burning myself by crimping instead of soldering.

Sean

Ive had the same problems with speakers, just because they are supposed to physically fit doesn't mean I wont have to drill a bunch of new holes in my metalwork to mount them. :-( I hope the burn heals up ok, I have always avoided burning myself by crimping instead of soldering.

We're not talking new screw holes, I have to file out part of the door panel because they're hitting the windows. It's the first time crutchfield has ever disappointed me.