Input-output selector

[reticent67]

Hello all,

I've been looking through this site for the last several months, just expanding my horizons and trying to learn more about audio. But now I have an obstacle I'm hoping some of you can help me overcome...

I'm putting together a computer for my car so I can play mp3's and watch DVD's and all the other good stuff PC's can do. I'm putting a M-Audio Revolution in it so I can have DTS/DD surround while it's playing DVD's. Speakers and amps for 5.1 will not be an issue.

Now, I could hook each channel of the Revolution directly to the corresponding amplifier channels, no problem. But what about when I want to listen to FM through the factory head unit? How can I make that also go through all six channels?

Here's what I'm thinking... I could design a circuit that would select either the stereo or the multi-channel input. I'm guessing then I would need a circuit that would split the stereo signal into 6 channels and send it through to the amps. Also, it would be cool if I could control the switching through a computer interface (but I can worry about that later).


So, how would I do this? Is it even worth doing, or should I look for another solution? I'm very very basic with digital electronics. If anyone can think of a better way or point me in the right direction, I'd really appreciate it. Thanks

[reticent67]

Okay, so I've thought it out a little bit more and here's what I came up with.

I'm going to use a multiplexer to choose a two-channel input. The 2-channel signal will then go through a buffer where it will be split into 6 channels (3 right, 3 left).

Then I'll connect a 6 channel SPDT switch between the buffer output and the amplifier inputs. One side of each switch will be connected to a multi-channel output of the Revolution, the other side will go to one of the outputs on the buffer. From there I can control which set of signals is going to the amps.

Anyone see any problems with this? Also, what are some good IC's to use in this circuit that won't degrade the sound too much?
I've ordered some samples of Maxim's Max4572 which will handle the switching aspect. Is this a good chip, or is there something else that's better? Also, what's a good chip to use for the multiplexing?

[xplod1236]

You can hook up the head unit output to the input on the sound card. Then, set up the pc, so that whatever comes in the input goes out the output. The sound card will do the 2-ch to 6-ch conversion.

[reticent67]

Wow... I feel like a total dick. I don't know why I was being so convoluted.

I think I'll just do what you suggested. Thanks.


PS - Please disregard the first two posts....