audio signal conditioning

[PlayaSlaya69]

Hi guys, this may seem like a fairly simple question compared to the other posts i've seen here but i still need some help nonetheless. What's a simple yet effective way of combining the left and right audio channels from a 3.5mm output input so that a single audio channel can be obtained to supply to a filter and then ADC. I've seen just a resistor being used in each channel and then the channels simply joined. Would this work?

I'd appreciate any help, thanks...

 

[Easyrider83]

No problem. Just join them by resistors. The signals have a common ground.

 

[PlayaSlaya69]

Thanks, i really didn't think it was that simple. I do have a question though, just for clarity, when the signals on each of the two channels are combined do they then become super-imposed onto the one channel?

Also what is the role of the resistors, are they just there as current limiters?

 

[murali_dece]

it is allways better to join two audio signals by two capacitors, one for each channel and other end of two capacitors are joined together and take it as final output with respect to ground. this will provide DC decoupling and make your final stage of previous amplifier in safe condition.

 

[Easyrider83]

Capacitors will work as a low pass filter.
DC voltage may be excluded before resistors.