Hook two computers to one speaker?

6

4

Is it OK to take the line-out from the audio card on two computers, hook them up to a y-adapter that finally goes to a single pair of speakers? I would just go ahead and try it, but don't want to blow up a sound card if it's a bad idea.

Thanks

DougN

Posted 2009-12-01T15:09:34.937

Reputation: 263

Answers

11

A single device outputting to multiple devices seems to work OK. It changes the electrical characteristics (impedence changes, but the tolerance of most devices is actually quite wide) and could theoretically cause damage, but has always worked fine for me.

However, multiple devices outputting to a single device is different. That's a situation where you're most likely to damage something. It might work fine, it might not. It might appear to work fine while slowly damaging components too.

Do you intend on running both sources at the same time? If so, you really should use a mixer. If not, then a simple switch box is the best way to go.

Brian Knoblauch

Posted 2009-12-01T15:09:34.937

Reputation: 4 313

3

Found a few places online that talk about building a very simple mixer to do this: http://www.tkk.fi/Misc/Electronics/circuits/linesum.html

– DougN – 2009-12-01T22:22:26.777

4

A solution that bypasses this problem (assuming the jacks are free) is to plug Computer A's line out into Computer B's line in, and then Computer B's line out into the speakers; this requires Computer B to be on for either to produce sound, but shouldn't damage any hardware.

Darth Android

Posted 2009-12-01T15:09:34.937

Reputation: 35 133

-6

Things that would blow up your soundcard are too much output or too much input. This won't be caused by splitting the output signal. Your speakers should be safe too, following the same logic.

Jonno_FTW

Posted 2009-12-01T15:09:34.937

Reputation: 1 280

2this is not about splitting but merging the signal from 2 amplified soundcards. the speakers would be safe alright, but what about the soundcards? – None – 2009-12-01T15:32:51.483

I covered this in my answer. – Jonno_FTW – 2009-12-01T17:31:04.040

@Jonno_FTW I think the point that you missed is that each soundcards output is attempting to drive the other's output. The splitter doesn't "know" which way we'd like the signal to travel. All the devices are linked. – Brian Knoblauch – 2009-12-01T21:12:50.753

Why not use a diode in the Y-splitter? – Jonno_FTW – 2009-12-02T07:28:19.637

1See @DougN's comment to my answer. You can make a mixer device. An off the shelf Y-splitter won't cut it. – Brian Knoblauch – 2009-12-02T13:34:48.013