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personal audio combiner

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New Member
I've been looking for over a year now for a personal audio combiner. A wearable device which plugs into my cellphone and my mp3 player at the same time (with different plugs) and combines their output and then the device is also is plugged into my headset. Microphone input from the headset to the device would be directed only to the cellphone, of course.

SkullCandy used to make such a thing - 'used to' - they discontinued it. It even had volume control on the mp3 output.

Why is this device not on the market? Or why can I not find it?

I've tried joiner, combiner, merger, and mixer (which gets all kinds of sound booth and DJ mixers, but none for personal audio cellphone systems).

I had someone knowledgeable in electronics explain to me that this is solvable - just cross the output of the cellphone with the left or right channel output of the mp3 player using a resistor which matches the resistance of the earphone, and also place a same size resistor on the other channel to match the volume. Depending upon the volume loss due to the resistors, I may have to add an amp or pre-amp to each channel, powered by a 9V battery.

I had someone else suggest using a summing amp.

So, I could make this device, but it being SO simple, why is it not on the market? I'd prefer to have it in a nice wrapper ... :)


Most Helpful Member
I can still recall the days when a phone rang like a phone and only made phone calls. :p

Those were the good old days. :)

Now I know people that carry cell phones that dont even have phone contracts!
Its everything but a phone! WTF? :confused:


Most people out there today would look at this as the perfect excuse to buy a new phone =) You should think of it as an option. Me personally I've never heard of such a thing, but your techie friend sounds about right, it would be relatively small just find something to use as a custom case for it. Altoids tins or the like would be the perfect size, just buy yourself a can of metal primer and some high gloss spray paint. The volume loss from a passive setup would probably be too much so you're likely gonna have to use a simple summing amp, not that complicated though. Use a decent opamp and you'll even get better volume than before. Not that those kinds of things don't already go loud enough =)
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