# CarPC Audio Help



## Cobby17 (Jan 28, 2010)

A little background...I am a Linux System Administrator, and I don't have any real experience with car/mobile audio, or any audio systems for that matter. So please bear with my audio ignorance; I'm hoping someone can shed some light on what I need to do.

I am going to put a carPC, of the LinuxICE flavor, in my truck. I figured while I'm doing this I might as well go ahead and upgrade the audio system in my truck. After talking with the local car audio place, I decided to replace the front 6x9s, rear 6s, and add a sub enclosure and amp. The audio guy said that I would need 2-3 (preferably 3) audio out ports (RCA) on the computer to properly run this setup. My first question is, why?

My next question is regarding external DACs. Since the computer I'm putting in my truck is a small ITX form factor, I can't find any motherboards with more than one set of RCA jacks. So does this mean I need to get some sort of USB DAC to break out the signal into multiple RCA jacks? If so, can someone point me to a good-quality DAC that (hopefully) works with Linux?

I could be completely misunderstanding what's going on here, so please feel free to correct as necessary.

Thanks!


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## Greg S (Oct 21, 2009)

You can either do an outboard DAC unit or use some of the better audio boards which have multiple analog audio outputs. One of the best resources for this type of project is MP3Car.com if you haven't already checked it out.


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## kapone (Sep 22, 2009)

Your installer is right. The reason you typically want 2-3 sets of analog outs (RCA or any other variety) from a headunit OR carpc, is because you want the FL, FR, RL, RR signals at the very minimum and if possible a C and Sub signal as well. The latter two are optional and can handled by outboard crossovers or the crossovers in the amps.

On a different note, although I don't know as much about LinuxICE as I do about Windows based mobile hardware/software, I can tell you that AV on linux is..well...tricky..to say the least. Drivers are your biggest issue. Make sure you choose your hardware carefully.


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## Banegio (Nov 28, 2009)

This allows you to control/process the front, rear, sub signal separately from the PC. You don't have to. Simple stereo output to 5 channel amp will give you sound. But you would waste the processing power of the PC.


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## MarkZ (Dec 5, 2005)

You don't need 6 outputs. You'd only need 6 outputs if you planned on using the carPC for audio processing, which it doesn't sound like you do. You can use the amp's crossovers or passive crossovers to handle that in the meantime. Or an external processor.

But, it should be easy to find mobos with 6 outputs! They'll be headphone jacks, not RCAs. So you just spend the $3 and get a headphone jack to RCA cable.

If you want an outboard sound card, there are plenty of USB or firewire devices that have multiple outputs. I use the ESI Gigaport myself. My mobo doesn't have a PCI slot, or else I'd probably use something like the M-Audio 1010LT that everybody raves about. But this may be beyond your needs.


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## Chrisjbell (Oct 19, 2009)

I've been checking out the various options for using a PC as the
audio source for a while. It'll be a lot more work than a commercial headunit but I think it will be the best overall solution for me. 

LinuxICE does look pretty good. As a sysadmin you shouldn't need to be too scared of hardware drivers, but that will be an issue. There are a lot more options going with Windows, but I'm leaning Linux for speed and stability. Today, at least...

Most of those little moboards have Intel HD audio built in - that'll support something like 8 audio channels. A lot of people use them quite successfully for car audio. 

I'll second checking out mp3car.com. Great resource. There are a couple of really good threads on here I found to be very informative.


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## Sergery (Jan 20, 2009)

I have been using the x-fi extreme music at home (modified Hotrodding the X-Fi) 6 channels, can be had cheap, and the sound is quite excellent. I am uncertain about linux drivers tho. I also have been using this diy dac AMB gamma2, which also sounds excellent and can be connected usb or spdif. The wolfson WM8741 which is one of the best DAC's around.


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