Engine whine - help...

Pseudo Nim · 08-10-2005, 09:40 AM

Well, I'm just another casualty in the war against engine whine.

I've gone through several cables, gradually increasing cable quality, and that did nothing. My Car PC is properly grounded (I actually re-did my grounding 'cause I thought it wasn't proper.... and that did nothing).

Then I thought, what if it's the case (I'm using a self-fabbed plexiglass case). I took a motherboard, held it in my hand in thin air. Note: if the RCA is plugged into nothing, I get no whine. Plug it into the motherboard. Bang. Whine aplenty (no power is applied to motherboard!).

Plug in motherboard to DC power - no change, still whine.

I thought, maybe it's the case. So I put it into a case, and bang! The whine was gone. Unfortunately, it was a desktop case, so I said okay, my Plexiglass case is ****, and I went out and bought a Mini-ITX case for my Epia (Casetronic 2699).

A night's worth of remounting everything, go to the car at 6:30 in the morning, plug in..... and the ******* engine whine is back.

The desktop case that I used was a heavy-duty one back from the 80s or so, so I'm thinking the material is different. Has anybody run into this? Maybe I need to isolate the case from EM interference, like build a mini-Faraday cage or something? Would placing two slabs of steel on top and on the bottom help at all, or would it be a waste of time? Or should I wrap it in EM shielding material?

Any thoughts would be appreciated.....

-pN

schreibers · 08-10-2005, 07:35 PM

Install a good ground from the case chasis to the car chasis? Or yeah you can do the whole EM shielding thing.

With my first setup stereo setup I had bad engine whine and instead of one big bolt to my ground (i had already sanded it to the bare metal during the initial setup) for the amps I did a bunch of self tapper screws in/around the ring terminal (obviously all touching the terminal) and it resolved the issue. Looked totally ghetto but you can't see it anyways under the carpet but it worked. In any situation we've come into with ground noise that we haven't been able to fix as a last resort it's fixed the problem when other things havent.

Pseudo Nim · 08-10-2005, 07:45 PM

Currently, what I'm thinking of doing is:

- taping the whole case with metal duct tape (not regular duct tape) (I heard that might help with shielding)
- using a fat wire (8ga or so), connecting it to the car body (like a seat bolt) and somewhere literally to the case (I have one like that, but it goes to the power supply's ground .... I guess that's not enough?)
- using a ferrite block on the +12V and +12switched coming from the car's battery to (possibly?) eliminate some noise along that line.

Does that make sense? Should I do something else while I'm at it?

Another crazy idea I had was getting 4 steel plates, 2 for top and bottom and 2 for sides, and duct taping the whole thing together. Looks ghetto as hell, but provides additional shielding?... (you can tell I'm desperate, hehehe)

-pN

maxxell · 08-10-2005, 10:57 PM

Are you using a ground loop isolator?

Pseudo Nim · 08-10-2005, 11:05 PM

No. From what I've been reading, a ground loop isolator seems to be a band-aid solution, and again, from what I've read, if my system is properly done, I shouldn't need to use a ground loop isolator. So I want to figure out what's up without resorting to one...

-pN

maxxell · 08-10-2005, 11:07 PM

Yeah, I was going to say to get rid of it. I had one in my setup and got painful whine. Useless devilish devices.

Sorry I couldn't help.

Pseudo Nim · 08-11-2005, 04:27 PM

No worries - thanks for the thought.

Actually, I was just reading your thread re: engine whine. I thought of posting my prob in it, but then realised thread hijacking is not cool. =)

Pseudo Nim · 08-14-2005, 12:57 PM

Okay, so I went all out crazy and done the following:

- replaced my case (switched from plexiglass to sheet metal)
- rewired some parts of the power supply system switching to copper
- put a ferrite clamp on the power wire
- grounded the case using a 6ga wire (yeah it's overboard, but do YOU like to hear a pseudo-turbo whine in your speakers?!?)

I am happy to report that I've cleaned up the system and removed virtually all noises from the system.

EXCEPT THE GODDAMN ENGINE WHINE.

Now I have a very, very pure engine noise in my speakers - no more static, nothing. Just engine noise.

I feel like punching someone.

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