Does an audio 'adder' device exist? If not, how do I make one?

Question

I'm looking for a device that takes several audio inputs (AUX and BlueTooth A2DP), merges all sound together into one line and provides a single output. Does a device like this exists? If not, is there a reason why not, or could I make such a device myself?

Answer 1

As others say, it's an audio mixer.



The most basic "passive" circuit is like this:

http://www.daycounter.com/Calculators/Voltage-Summer/Voltage-Summer.gif



The resistor value should be higher than the minimum any source can drive, but lower than the input of the next stage.

1K is generally suitable for what you need.



With a passive mixer, the output level is divided by the number of inputs used, so three inputs would give 1/3 the output compared to a single directly-connected device.



Active mixers use preamps and/or an output amp to boost the level up again.



eg. this has an output amp with variable gain (and x2 for stereo)

http://www.circuitlib.com/images/tutorials/4_audio_mixer.jpg



The next level is to add gain controls to each input to balance the levels, something like this (showing one channel, two needed for stereo)

http://colomar.com/Shavano/opamp-s3.gif





Put it all together and you get something like one of these:

Answer 2

Hi yes it is called a mixing desk.

Answer 3

its called a mixer. or you could build/buy a summing box but it wont combine different types of signal. you would need external components to add bluetooth and all that onto it. https://www.sweetwater.com/store/detail/SplitMix4 something like that would work at least for the analog audio parts.

Answer 4

The basic name for such a thing is "mixer".



The Peavey PV6BT might be a candidate for you.