For two years now, I have used a PC-sound system in my 2CV. A cheap set of one active sub(built in amp) and two speakers. Sub takes 12V in directly from car, just had to cut of the thing that transform 220V AC to 12V DC. Put in in the car with no mods to the car and used my GPS as a MP3-player. Worked great! I have the same setup in my DS.

When the sub is on, getting power from the car, and the MP3-player is not charging, the setup played perfect. But when I put the charger for the MP3-player on, there was a "crackling" noise when engine was running. Maybe electrical noise from the ignition? It was not a big problem, cause the GPS/mp3-player could go on for 4-5 ours in one charge. When it needed charging I just took a break from the music, or ignored the noise, it wasnt that bad. I have the same problem in my DS by the way. Until now just thinking it's because of the pc-speakers not belonging in a car.

Two years ago, I tried finding the cause of the noise, but gave up after no luck with the things I tried. And it was the same in two different cars. As I said, I thought the problem was the PC-soundsystem.....I mean, it's not designed for being in a car.

So now I wanted better speakers and a headunit in the car, so I dont have to fiddle with the MP3-player every time I go in and out of the car on short trips.

Pulled out the old PC-setup(took 120 sec) and put in a set of 10cm speakers in front and a headunit under the tray.(took more than 120 sec ) Switched it on and it sounded good! (An active sub is going in too, if I get this noise-thing sorted)
But how long was Adam in Eve...when I started the engine, the "crackling"-noise heard with the old setup was twice as loud! Really awful! The crackling noise is varying in intensity with the revs of the engine. It's not possible to have it like this!!

Meaning, it was not the earlier PC-speakers or the MP3-player that caused it earlier!
It's driving me mad!!! I'm fed up of googling the problem....

Summary: New sound-source, new speakers, new places where power and ground is connected, new original spark plugs, new silicone HT-leads, new coil, 123-ignition and generally good condition of the whole car. Dont have any other problems with the electrics.
And yeah, I tried a noise-cancelling-thingy from a car audio specialist, and it did nothing.(That was with the old setup)

Really would like some tips on what to do here, as I have no clue anymore........

have you put suppression on the alternator?
also may be your voltage regulator if its an old mechanical one


but as you see from Russ's stereo post i know nothing about radios

Sean

Make sure the speaker cables aren't any where near power cables. The audio lead for my sub runs the opposite side of the body to the loom and the cable for the rear speakers goes along the floor.

Hi! Speaker cables are clear from power cables. At the moment there is no sub or amp, just a head unit and two speakers.

"Suppression on the alternator"? Like a condensator or something?

I am beginning to think there is something with the car, and not the sound-system. So yes, I wish I had an electronic voltageregulator to try out..... The ones I have are all original mechanical ones.

I will try with a different headunit tonight though.....
And maybe disconnect the plug on the regulator? Will that prove anything regarding alternator/regulator?


UPPDATE:
Problem solved!!
I tried with a different headunit, an old one from my modern van. And the noise was gone! So, what made all this trouble with my new audio-setup was a piece-of-shit car radio.
Why I didnt try a different car radio before making this tread? Well, the radio was brand new, never been used.
AND it still works just fine in my 2001 mod van., but in the 2CV it choses to play the "electric life of the 2CV". Unfortunate, I have had it laying around for over a year, so guess it's to late to take it back to the shop.... Oh well, gotta go and buy a new one. This time maybe spend a bit more money on the new one
I'm just glad it was that easy.

All try and find a good one with USB, SD-card(optional), AUX in front and removable frontpanel.