Connecting 2 audio sources to 1 set of speakers

Pakman117

Senior member
Jan 20, 2001
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Hi, I only have 1 set of logitech 5.1 640 speakers that I want to connect both an xbox and pc audio outputs to. Right now, my setup looks like this, and here's a closeup of the adapter I have. I noticed, however, that not all my speakers work with my current setup unless I connect the speakers directly to my motherboard (MSI Neo2 Plat with ALC850 8 channel sound). Is there a way, possibly with different connectors, to get all speakers to fire while being plugged into both my PC and xbox? It's a real pain to either lose speaker functionality, or keep switching the speakers between my PC and xbox. Thanks for your help.
 

YOyoYOhowsDAjello

Moderator<br>A/V & Home Theater<br>Elite member
Aug 6, 2001
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Which speakers don't work? Is it the center channel that doesn't work? Does the sub still work like this?

Is that RCA adapter both changing the RCA to 1/8" jacks and splitting it to 2x stereo, or is is changing RCA to two 1/8" mono jacks?

EDIT: whoops, forgot to look at the closeup. It does seem like that's doing stereo outs.

EDIT2: what happens when you take the x-box adapter out put and just plug one of those (the green one let's say) and plug that into the line-in of your integrated sound? Does it only come out the front right and left, or does it map it to all the speakers? Is there some mode in your sound utility program that would allow you to do this?
 

YOyoYOhowsDAjello

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I was looking through google's images... did that adapter come with your z-640's?

google image

I don't have this system so I wasn't aware it came with that adapter.

I think your problem is that you're giving a signal to your fronts and rears but not feeding it a center signal. The sub works because the speakers have an internal crossover and are feeding the sub the low parts of the input it is getting... but the other half of the yellow/brown jack (the center/sub one) isn't getting a signal.

So, you need to get the center a signal. I guess you'd want a mix of the stereo front signal (or stereo back since that adapter is giving you the same signal to the back speakers it appears).

The easiest way to do this is if your motherboard was able to take a line input signal and map it to 5.1 like I mentioned earlier, but I have no idea if it's able to do that.

Another option might be to use the digital out of the x-box (I don't have one, but they have a digital out, right?) and then buy a soundcard that can take a digital in... but that would probably be pretty expensive.

That leaves you with more adapter stuff. I think you'd need to split the signal coming out of the adapter with a y-adapter and then take that stereo signal and somehow combine it and feed it to the center/sub input on the speakers. I've never done this before. Would a simple stereo to mono adapter do this? If so, then you'd just need to add a 1 male to 2 female y-splitter into one of the outputs on the adapter box (the green one let's say). Then you would plug the stereo to mono adapter into one of the outputs. The other half of that y-splitter you'd hook-up the 2 male to 1 female y-splitter you already have hooked up for the fronts. For the end that you just changed to mono, you'd need to get another 2 male to 1 female adapter and plug one of the stereo inputs into the mono adapter and the other into your center/sub output of your motherboard.

This working is dependent on a few things that I'm not sure about.
1. The stereo to mono adapter combines the signals into a mix of both
2. A stereo plug will fit into a mono jack and split the signal back into two duplicate signals

I've never used mono stuff, so I'm not quite sure how it works, but I'd imagine that's how they work. I wouldn't try this until someone else tells you this would work.

If you don't understand what I wrote, I can draw you a quick little paint diagram if you want.
 

Pakman117

Senior member
Jan 20, 2001
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The sub and the center channel still work regardless of what I do. The center channel (yellow) plugs directly into my motherboard.

Depending upon how I have the red and black cables (if I have the red going into the computer and the black into the black stereo box per se) determines which speakers work. Using that configuration, my right side (front, back, center, sub) works. If I switch it, my left side (front, back, center, sub) works.

If I plug the speaker's green connector (front) into the black stereo box's green connector, both the front speakers will work. Vice versa for the black (rear) speakers.

Here is a diagram of what I want to happen, but with all speakers working
 

Pakman117

Senior member
Jan 20, 2001
303
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81
Yes, that adapter came with my 640s. I tried fooling with the NVMixer and theres a feature called clone, but I think this might clone what'd going into the front speakers to the back?

I'm not quite sure what you are saying in that paragraph. Are you saying its necessary to combine the center speaker into the mix somehow? If you could provide a paint drawing, I would very much appreciate it.

I don't understand why there isnt an adapter that either takes input from the xbox or from the PC, or both (like shown in my drawing).

Thanks for the replies, keep it coming.
 

YOyoYOhowsDAjello

Moderator<br>A/V & Home Theater<br>Elite member
Aug 6, 2001
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Ok, I was thinking your center channel wasn't working while the fronts and rears were... but since that isn't what's happening, the stuff I said before isn't what you want to do.

I think that clone might be exactly what you want to do. If you have a male to male 1/8" cable, try plugging it into the green jack of the adapter and the other end into the line-in of the motherboard (blue?). That might do exactly what you want.