ObRTFM: I've gone over the FAQ and believe I've got everything wired to the same ground potential, but the sonic evidence indicates otherwise. Any additional advice would be welcome.

Vehicle: 2003 Honda element EX.

Factory System: Double-DIN head unit with standard Honda wiring loom, plus three additional connectors: antenna, subwoofer line-out and auto-detect aux-port input (for the in-dash 1/8" connector). Headunit, however, only puts out line-level, as there is a separate OEM amplifier in the passenger kick panel that does 4-channel plus subwoofer amplifying (4x50W max, 1x70W max, not sure of the RMS). The equipment was all manufactured for Honda by Alpine.

The factory system is 100% noise-free. It also plays CDs noise-free even if three of the four "extra" harnesses are detached (antenna, subwoofer, aux-in socket), leaving only the standard Honda/Acura in-dash harness connected (checked that just in case there were ground requirements for the other harnesses).

I replace the OEM headunit with Pioneer DEH-750MP connected through 2 (cheap) two-channel speaker-level to line-level converters and a honda-compatible mating harness. Slight noise ( when headunit's amps are on). Thumps a little bit when amps turn on of off. If I disconnect the eight speaker-side wires, no noise but no music. If I disconnect the "system remote control" (as labelled by Pioneer) from the amp turn on (not labelled), again, no noise but as expected, no music.

Important: Originally, I had the output polarity of the line level converters reversed. They had RCA outs, and I cut off the RCA connectors and wired each shield to the channel's positive and each center conductor to the channel's negative, but the noise was tons (unbearably!) worse then. I took the harness inside, uncrimped, reversed the polarity, recrimped, went back out and hooked it up and, for a moment, I thought I had fixed the issue entirely. But then I noticed the noise was still there, just substantially quieter. I was unsure if that was the 'right' fix or if I should have been swapping the polarity of the inputs to the converters instead, but the wiring up to the converters seemed to be wired with correct polarity. Might have to try swapping the inputs and outputs this time. Or, more likely, replacing these with higher end units? Could this be a channel ground vs. common ground thing?

To be sure, switched back to the OEM head unit, yup, no noise.

Switch back to the Pioneer + converters, yup, noise. I can hear the CD spinning up, alternator whine, etc.

Add the empeg MkIIa (riocar) to the system by plugging its ISO plug into the ISO socket supplied with the unit and wired in parallel with the pioneer harness. This adds substantially more annoying noise (harddrive, processor, etc), regardless of whether the empeg's line level output is connected to the head unit or not.

Add the Parrot CK3000 to the system, by patching it in through the ISO plugs/sockets (described below): symptoms are even worse! Grr.

Pull it all out and put the OEM unit back in. Leave the dash, subwoofer cover, glove box, etc. all in pieces. Sweet music. Fall back, regroup, live to fight another weekend.

My approach on the wiring was to do things as modularly as possible, with no cutting of the OEM or any product's wiring. In order to support the CK3000, I needed to use the speaker-level outs of a new headunit to feed the ck3000, then attenuate the output down to line level before feeding that to the OEM amp. It also required including a conversion of the OEM wiring to ISO plugs, and a conversion of the headunit/empeg's wiring to an ISO double-socket.

While I felt this next item may be important regarding the noise problem adding the empeg, it doesn't explain the above problem with using just the new headunit: the empeg's power/control harness is wired in parallel with the headunit's harness to the double ISO-socket using the extra ISO plug included with the empeg. I've checked the connections of the ground, power and ignition wires connections (all three ways) with a multimeter, while wiggling, all seem to be good and resistance free.

I've done whole system continuity tests from the 'to OEM-wiring' end to the 'to empeg' or 'to pioneer' ends. No problems. How concerned should I be regarding the other wiring vs. chassy grounds or the line-level adaptors above?

Here's a (helpful?) diagram (without Parrot CK3000):

http://brendan.org/element_wiring.txt

Thanks for looking,
Brendan

This adds substantially more annoying noise (harddrive, processor, etc), regardless of whether the empeg's line level output is connected to the head unit or not.

The very first thing I'd try is to upgrade the stock harness ground (didn't see you try that) - heavier gauge and to a known good ground point (sand away any paint so you get down to clean metal against the ring connector on the wire). Snip the ground wire immediately after (1.5-22 or so) the plug/socket on the car harness, attach your heavier wire there. No harm done to any stock things...

/Michael

A few quick things:

You said you used "2 (cheap) two-channel speaker-level to line-level converters" to hook the Pioneer head unit to the Element's factory amplifier.

Questions about that:
1. Are you sure the Element's factory amplifier is really line-level input?
2. Do these cheap converters have power connections or are they passive?

If they have power connections, they could be causing the ground loops.

If the Element's factory amplifier is truly a line-level input device, have you tried connecting the empeg DIRECTLY to it without involving the Pioneer headunit or any other converters or components at all? Remember the simpler the layout, the less chance of ground loops.

Why do you want the Pioneer stereo anyway? If it's just so you can play CDs, forget it. You'll never play CDs again anyway.

Final question: Why did you buy the ugliest car on the face of the planet?

Oops, forgot to answer the first questions on my first post attempt!

> 1. Are you sure the Element's factory amplifier is really line-level input?

Yes, those using a direct aux-out implementation find it works just right.

> 2. Do these cheap converters have power connections or are they passive?
> If they have power connections, they could be causing the ground loops.

Passive. I'm going to try a passive Scosche 4-channel converter this weekend instead.

> If the Element's factory amplifier is truly a line-level input device,
> have you tried connecting the empeg DIRECTLY to it without involving
> the Pioneer headunit or any other converters or components at all?

Not yet.

> Why do you want the Pioneer stereo anyway? If it's just so you can play CDs,
> forget it. You'll never play CDs again anyway.

Due to:

1. The speakerphone requiring speaker-level signals.
2. Often my passengers have music on CD they want to share. When I feel inclined,
I share the stereo.
3. Don't have an empeg tuner. They're too pricey.

I suppose I could interface the speakerphone post-amp if the wiring will reach (debatable), and wire up a portable CD player to the aux-in on the empeg, but that seems non-optimal if I get this all to work.

> Final question: Why did you buy the ugliest car on the face of the planet?

Heh, I knew someone would ask.

My last two cars were a plymouth colt and ford taurus, both second hand, so I decided to go to the other extreme with the new car...

...but seriously: reliability, safety practicality/flexibility and value.

It just hit that sweet spot. It also seemed like a good road-trip/car-camping car, due to the roominess and all the little pluses. Rather than go on about all the pluses, I'll just say, read the reviews and test drive articles. Here's an amusing review (not the best, but fun to read):

http://www.thecarconnection.com/index.asp?article=5216

I still have issues with the look, but it's fun, treats me well and I love driving it. We'll see how the relationship works out.

-brendan

> The very first thing I'd try is to upgrade the stock harness ground
> (didn't see you try that) - heavier gauge and to a known good ground
> point (sand away any paint so you get down to clean metal against
> the ring connector on the wire). Snip the ground wire immediately
> after (1.5-22 or so) the plug/socket on the car harness, attach your
> heavier wire there. No harm done to any stock things...

Good point, will do. Thanks

-brendan

Why did you buy the ugliest car on the face of the planet?

Oh, come on. It doesn't even hold a candle to the Asstek.

Oh, come on. It doesn't even hold a candle to the Asstek.

Once upon a time, the Vega was the ugliest car on the planet. Then came the Asstek, and it took the throne of the ugliest car, pushing the Vega to second place.

I think that, in order of ugliest first, it's now:

1. That boxy Scion car (forget its model name).
2. Honda Element.
3. Asstek ("Dude, your car looks like ass").
4. Vega.

Apparently, the Scions (the one you're referring to is the super-interestingly named xB, as opposed to the other model's equally ingenious xA) are available only in CA, so I'm not forced to see them. I'd still argue that the Element has a ... well ... element of cuteness to it that makes it just better than the all-ugly Asstek.

And I don't see why you'd think that the basic stumpy fastback Vega is all that ugly when compared to its contemporaries, the Pinto, Gremlin, and, especially, Pacer.

Although I agree that the Pinto/Gremlin/Pacer were butt-ugly, they had a certain charm to them that is totally missing in the Vega. I suppose in much the same way the Element holds a certain charm for you.

..my friend just traded in an Audi TT for the Element!

Two of the guys on one of the Element forums sites traded in or sold their WRXs for Elements. Yeah, weird.

-brendan

I didn't like them at first, but i gotta admit they are growing on me. Mainly because of the utilitarian aspects... have you seen the inside of that thing? You can hose the damn thing off if you want to. I could definitely understand wanting one if you do a ton of outdoorsy activities. And comparing it to the Asstek is being way to harsh!

Actually, you can't really hose them out, that's a stretch: while all of the wiring 3" from the floor or lower is water resistant, there aren't any drain holes in the floor. You can *sponge* it out, no problem.

Ok, replaced the cheap-ass speaker-to-line level adapters with a Scosche OEA-4 (4-channel, adjustable). That fixed up the ground loop problems entirely. Before rewiring, I popped open the OEA-4 on a hunch and verified that each of eight lines has a capacitor wired in serially on the headunit side: can't get to ground through a cap! Even the integrated CK3000 bluetooth/carphone works great.

Thanks for listening. Once the dash-kit arrives to make the whole thing less frankenstein-ish, I'll post some pictures.

-brendan

Ah, cool. Glad you got it working!

Yeah, when you said "cheap", alarm bells went off in my head.

Yeah, should have gone off in my head *before* clicking-to-buy.

I wouldn't be surprised if the Alpine-supplied Honda OEM headunit actually had caps inline with the line-outs in the output stage...I might crack it open and check that out.

-brendan