Thread: Two audio outputs simultaneously into one amp input - possible?

OK, did a little more research and will update my own post:

You definitely shouldn't do it with just splitter cables because the voltage frome either ouput can possibly damage each other...so, in my mind not worth the risk and not the way to do it.

You would need a 2 channel mixer that would accept two audio inputs and have one audio output. Now, that is what I will be trying to find.

Also, I suppose I could get a sound card that has a line in as well as 5.1 out and send the stock HU into the sound card line in and use the software mixer to mix both audio sources. I believe the better sound cards will simply pass through the audio from the HU when the computer is off.

Let me know if anyone has any input (no pun intended) here.


Thanks,
Eric

EDIT: I found this site that describes how to build your own simple mixer circuit.

Does the 2005 Evo have factory options for satellite radio and/or CD changer?

Originally Posted by amthar

Does the 2005 Evo have factory options for satellite radio and/or CD changer?

I haven't yet looked at the back of the HU and AMP, but I have seen pictures on other forums. And by the looks of it, there are no other connectors besides their one proprietary cable that carries power and sound outputs to the amp, and the amp has that one input.

I know what you are getting at, but it doesn't look to be an option. I was contemplating getting another HU with an AUX in, but that route is too expensive, and an AUX in wouldn't enabling mixing of the two sources.

Eric

Originally Posted by shotgunefx

I had the same dilemma. Instead of building my own, just figured I'd use my line in. Like that I'll be able to control both volumes through the pc instead of seperate controls.

Had no luck finding anything cheap pre-built that wasn't really expensive.

That's what I think I am going to do, too. But I was planning on gettin the M10000 board, and if you use the 5.1 then the three connectors are all changed to outputs. So, I would have to go with the external sound card, like that audigy 2 NX or something.

However I do have a question about that. Is the line in jack just two channels? I don't really mind...all I really need from the HU is stereo anyway, but I just wanted to make sure and gather the right adapter, y-cables that I would need.

The MITAH adapter that I spoke of changes the Mitsubishi proprietary cable into 4 RCA outputs and a power wire for the amp. So, to put that into the line in and still keep all speakers getting sound, I would have to get two RCA Y-cables and then a RCA Y-mini jack cable, which would plug into the line in, correct? That should still separate L-F channels and send sound to all channels, IE front, rear, sub.

Thanks,
Eric

Originally Posted by shotgunefx

The line-in is just a stereo input.

The way your thinking about using the two 1/8 inch and feeding it to one line-in jack, you'd still have the same problem of mismatched inputs.

The four RCAs, they're going to be Front L-R and Back L-R, so keep in mind your F-R balance adjustment wont' work right.

I am aware of not having the F/R balance at that point. I don't think I have ever changed the balance on any radio I have had. I just care about getting sound and L-R separation to all speakers.

Originally Posted by shotgunefx

But something doesnt' add up here. The Adapter you bought, is it a HU or AMP harness. If it's giving you four RCAs, they are going to either be four outputs from the HU to an aftermarket amp or or 4 inputs to an amp from a new HU.

The cable can be used both ways. Mitsu has the same din plug coming out of the radio and plugging into the amp. So, the cable can be used to either replace the stock amp or stock HU, just like you described.

The cable looks like this:


and their description.

Also, the sub output/input is on one of the channels.

Originally Posted by shotgunefx

Also, if you drive the amp from the soundcard, most are I believe around 2.2V rms. My Infinity HU puts out 5v. So when I hook up a line out to my amp, it's very soft volume-wise. So I had to get a line driver to bump up the voltage. (Pac Turbo1 Linedriver)

Are you referring to the voltage just for the line out or the actual power line to the amp. For the power line, I am going to let the stock HU power it up as normal and also use the M1-ATX to power it up with the remote turn on.

Eric

Originally Posted by shotgunefx

I get that. Here's what I'm driving at.

HU -> ???? -> AMP -> Speakers

I'm assuming the soundcard is in the middle. So you'll need two of those cables would you not? One to go from the HU to whatever ends up in the middle (PC, Mixer, etc) and another to plug into the amp.

Yes, you are correct on both assumptions. I was planning on putting the soundcard where your ???? is and using two of those MITAH cables.

Originally Posted by shotgunefx

The signals coming out of the stereo are normally around 5v rms IIRC. So if the HU is getting fed into the PC, and then to the amp, the PC is only going to output ~2.2v so at maximum volume, the PC will only drive out a signal half as loud as the HU can. That's what happened when I ditched my HU and just used my Sirius. So I had to get a line converter to increase it.

Not the most knowledgable audio guy by far, but I wonder if you can damage your soundcard by inputting a 5v signal?

I see what you are saying. If that's the case, I will have to see how it sounds. If it's simple a scaling of the volume, I will just adjust the volume with the sound card controls to the level I want and use the stock HU controls for the volume from the stock HU.

I don't know about damaging the soundcard either. I guess I will find out.

Although all of this discussion is why I started this thread in the first place. If someone has an easier solution, like a cheap mixer (I found a 4 channel mixer for $36) or something like that, I may go that route. Keep the suggestions/comments coming.

Eric