Car radio "hack" is EASY!!!!

**THEMP3KID** · 07-13-2002, 01:37 AM

For those who are still pondering how to get the sound from their computer into their car speakers, ITS EASY!!!

My player was going no where, I had had it in teh car for about a week, listening to music with headphones (I wasn't driving) fearing all teh time that my linear supply would fail, and kill all my copmputer gear. That didn't last long, so, it all got ripped out again..

lol

Well, today, I finally got around to doign something. I pulled teh radio out (with permission of corse, as it isn't my car) and ripped the cover off..... I knew how I was going to go about this, and made quick work of it. All I did was tap into the volume pot, on teh input side, this means, that the volume control can be used for adjusting teh MP3 volume. Obviously this now meant that there would be 2 signals being fed to the amp (The radio, and the carputa), but by simply removing teh guts from an old casettee tape, and insertign that whenever I wanty to use the carputa, it disables the radio, and makes it all good..

Perhaps you caould try this??? FM SUX!!!!

**THEMP3KID** · 07-13-2002, 07:19 AM

weeelll, it works BEAUTIFUL!!! except that teh computer interferas with it like ANYTHING!!!! any ideas?? the interference isn't from teh sound card, as the volume control on teh radio has no effect, but the noise is only there when the radio, and computer are on, so, there must be interference getting into the amp, SOMEHOW!!!! :P BTW, the interference is caused by the harddisk..... you can hear it spin up, and read, as well as go "CLUNK" "CLUNK" "CLUNK because the voltage isn't high enough. .

lol

**eugenen** · 07-13-2002, 11:03 AM

Could be your sound card. I never noticed the background noise from my laptop untill I bought decent headphones (was using the set from a >$20 radio, so they didn't have the best frequency response). I hear a lot of hard disk noise on my new headphones, the hard drive , the wireless nic, etc. It has a cheap ess chipset. I fear I will have the same problem as my mp3 player has just been going through a casette adapter which losses a lot of the signal.

**Rob Withey** · 07-16-2002, 03:44 AM

I used to use a tape adapter and had reasonably clean sound. I then did the direct hook into the head unit and I got ground loop noise (alternator whine and hard drive noise). Quickly killed with a ground loop isolator. I also switched to using the headphone out instead of the line out on my sound card for the better signal to noise ratio it gives (more signal, less noise).

Yes, the mod is easy, like you said, I did it ages ago with a relay to switch over the audio, controlled by the parallel port on my player.

Rob

**THEMP3KID** · 07-16-2002, 07:38 AM

Well, I was originally using an ESS sound card, but have now upgraded (found in the bin) to a SoundBlaster16..

I think I may have a ground loop, but would rather not use an isolator (it seems like a patch up job, and costs money

) Could I just cut the ground line in my audio cable?? well, I am going to do it anyway.. lol

**Aaron Cake** · 07-16-2002, 08:07 AM

Originally posted by THEMP3KID
(it seems like a patch up job, and costs money ) Could I just cut the ground line in my audio cable?? well, I am going to do it anyway.. lol

Wait a sec...A groung loop isolator is a "patch up job" but cutting the ground cable is not?

**THEMP3KID** · 07-16-2002, 08:11 AM

Okay, well, obviously grounding the computer, adn the car radio to the saem spot isn't possible.... cutting teh ground isn't a patchup job, teh cable is still shielded from one end, but no chance of a ground loop..

**MikeHunt79** · 07-16-2002, 08:53 AM

Does it sound worse when changing songs, or when the hard disk is seeking? If yes then I had the exact same prob when using a linear reg to get +12v to the carputa (my first setup.... 486@100mhz, sb16, and a 30gb hd running mpxplay). The noise worse if i had the car lights on, or my amp cranked up, cause the input voltage to the psu was lower. You could try using a LDO linear reg, it might help, but i eventually built a full 2.5 sproggy that sorted it.

**Meatballman** · 07-17-2002, 09:17 AM

I'm not sure cutting the ground in your audio cable would do anything...I've read some about what causes ground loops, and that doesn't sound like it'd help. Please let me know why that would help if it does.