HOW TO: Get sound from PC to Car Stereo / Amp

Yes.

To make things simple, if you have the computer in the trunk...

Run a USB extension cable to behind the headunit area.
Put a USB 2.0 Hub on the end powered by 5 volts if you have USB devices up front, like a Keyboard/Mouse reciever.
Then buy a cheap USB soundcard, SB MP3+ is ok. Plug it into the hub. Get a 1 foot RCA cable and hook the USB Soundcard up to the Headunit. The MP3+ has standard size RCA outputs.

That way you don't have to run a 1/8th extension headphone cable up front or a long RCA cable up front and you can use the USB cable for 1 million more things.

Also it won't pick up any line noise if you have any.

Ok I need some help guys. I think I've misunderstand how digital audio signals work. I see the great diagrams offered in this thread which indicate several 3.5" outputs can be split from a 5.1 surround card to make 5.1 sound.

I originally didn't think of it this way. Please let me know if this won't work or doesn't make sense, because I'm trying it now and it doesn't seem to work.

I am running the Digital Out from an Audigy card to the Digitial In of a Sherwood X-DTS80 Circle Sound processor. I was doing this thinking the discrete channels would be transmitted to the DTS processor and then it (the Sherwood via its independent outputs for 5.1 channels) would separate the sound properly. Then each of these outputs would go into a 6-channel amp, then to the speakers. I get NO sound at all. FYI I have the Digital Out settings in Windows set. The DTS is also seeing some form of digital signal because as soon as the Audigy card initializes the blinking "Digital 1" on the face of the DTS goes solid. I also tried this with "Digital 2" and same results.

I've tried setting the Windows to analog, then running a signal to one of the Analog In inputs on the DTS. Then to the amp and to the speakers. That works fine.

SO, is my theory that this should work wrong? I connect my digital Cambridge Soundworks speakers to my home PC via one cable. But, then again, the Sherwood is a different processor and the speakers are analog, not digital like the Soundworks speakers. FURTHERMORE (please bear with me ;) ), is the idea of a Digital Surround Processor used along with a 5.1 surround card useless and redundant? I don't know. I didn't think so but maybe it is.

Anyway, here's a quick down and dirty diagram of what I'm doing. Please advise if I should just be using multiple (3) outputs from my Audigy and splitting them. Also please let me know if what I'm doing should or shouldn't work (Digital Out to Digital In). Thanks a ton guys.

One last sidenote: How does splitting an output accurately get translated to left/right? I guess I just don't get this. Or is the same signal sent to left/right and there is no true sense of each. Thanks again.

http://www.james-haas.com/Carputer/speakerHookup.gif

I dono, maybe check the spdif settings in the control panel for the SB Live?

Seems like it shoud work.

Thanks. At least now I know I'm not crazy. It seemed like it should work.

I don't know. I have the speakers set up as 5.1. I have the sound settings as Digital Out.

I don't know. Maybe the Digital In is broken on the Sherwood, but it doesn't work for #1 or #2.

Hmmm. Back to the drawing board I guess.

Did you click Digital Output Only on the Creative Speaker Settings screen?

Goto control panel and click on AudioHQ and make sure you don't have Mute Speakers when using Headphones.

Also play around with the Decoder Tab.

Yeah, that's what I meant when I said "Windows Digital Out". :)

The X-DTS80 is getting a digital signal. Because it has three options, analog, digital 1, and digital 2- if no signal exists on either or both of the digital lines, those inputs just blink. When I have the digital options set in Windows and connected to a particular line, that input stays steady and a DTS icon appears on the X-DTS80.

I am seriously considering going the Extigy route. I just read a great thread about the Extigy and its ability to convert all stereo inputs to 5.1 and process 5.1 Dolby Digital. All in real-time. And it switches between the two modes automatically.

If space isn't a factor (for me I can fit it), then I think it could be a great option worth exploring. In any event, I'll probably pick one up and try it out.

Thanks for the help. BTW, if anyone wants to see the Extigy thread, it's here:

http://www.mp3car.com/vbulletin/car-audio/39383-digital-processing-options-with-5-1-a.html

Dumb question. When using like say the Audigy, is there any sound deg. from using the analog-dig rca adapter? i use them at home for my desktop into my home theater but havent noticed a difference. should be exactly the same yes?

Im sure there is, but not eanough to notice...the only way you would really notice a chance in the sound is if you where taking it across long distances.

well like i know sometimes if you rotate the adapter while sound is moving through it there could be some static. what about the vibration of the car, bumps etc.....

I think the OHM's or resistance changes when you twist it thats why you get static.
I'm not sure about this one though. Anyone else?

I don't get any static over bumps, you have to hit a real hard bump to shake the rcas to twist.