How to run 2 computers off of one set of computer speakers?

[Denvers Dawgs]

I have these speakers


I'd like to run both my wife's and my own computer to this one set. I have 2 of these Multimedia Volume Controls, one for each pc.
.
Now i tried to run both controls to the back of the speaker by using a headphone splitter cable,
as well as one of these

but having both computers volume controls plugged in this way caused a humming/hissing sound. So is there some way I can use both pcs on this one set and still have each use there own volume controls?

I tried plugging her volume control from her line OUT to my line IN on pc, and it seemed to work fine (no hum/hissing), just needed to adjust the line in vol. But the problem is, if I have my volume turned low then even if her volume is @ max, she can only go as loud as my pc is set at (making her go to my computer to turn up the vol). So what I'd like to do is some how directly run both volume controls to the single input in the back of the speaker itself. But everything I've tried I get the humming/hissing? any ideas?

[MOVIEGEEK]

It won't work, you have to get an A-B switch such as the MK-1:
http://electronicsusa.com/mk1and2.html

[redwudz]

The best way would be to get a selector switch. But you would only be able to use one PC at a time. But if you don't need a really good sound system, it would be easier to pick up a second set of economy speakers. Trying to use two inputs connected to the same speaker most of the time with get you hum or distortion.

[Denvers Dawgs]

yup, that's what I may do. For now though running it through my line In is doing the job (for now.)

[classfour]

KVM audio switch

[Constant Gardener]

Op amp and a few resistors.

[blinky88]

If the speakers have RCA connections all you need is a pair of RCA "Y" connection cables from the speakers to the computers, I am currently using that setup. You need to have 2 connectors shown in picture 4 connected to the "Y" cables.

[Denvers Dawgs]

no rca connections just a single 1/8 head phone type jack for the input.

[blinky88]

That should not be much of a problem. Go to a local electronics shop and buy the input connections you need and replace the RCA input connections .... it is not a big job.

[budz]

as suggested just buy another pair of computer speakers.

[blinky88]

Hi Budz,

Why would you suggest "buy another set of speakers" when it is so simple to replace the RCA connections with 2x1/8" mono connectors ?

[netmask56]

Connecting 2 outputs together is not good electrically and generally results in hum and or a ground loop. The easiest and safest way is to get another set of speakers. In the worst case scenario you could blow a circuit board. I've seen this happen and I was the local technical guru who had to fix the bloody mess. Outputs from any audio amplifier at the power out (or speaker out) stage should never be paralleled. At and earlier voltage stage like line in that's ok just a couple of 20K ohm resistors if you want to be fancy. When you parallel the output stage you halving the output impedance and allowing the amps to go into instability, the current flow can also double in some designs.

[budz]

Hi Budz,

Why would you suggest "buy another set of speakers" when it is so simple to replace the RCA connections with 2x1/8" mono connectors ?

cuz you can get cheap computer speakers.

[Denvers Dawgs]

All set guys I'm sticking with line in process for now. Probably will get some other speakers at some point.

[blinky88]

Budz, I hate to disagree with you as you have given me a lot of good advise in the past ..but.. IT IS A SIMPLE TASK TO REPLACE THE RCA PLUGS, both of my computers are operating with one set of speakers, no problems whatsoever.