I have a Behringer X2222USB mixer.
I am trying to go from the PC 1/8" stereo out to the mixer 1/4" line in and achieve stereo sound.
I'm using a 3.5mm 1/8" TRS to Dual 6.35mm 1/4" TS Mono Y-Cable
I am monitoring with headphones plugged into the phones jack of the mixer. I route the signal to the aux 1 bus.
When I do a left channel sound test, I hear sounds from both speakers. The same thing applies to the right sound test. I can unplug the left line in and not hear anything at all when playing a left channel sound test. This also applies to the right line in.
I did the same thing using the RCA inputs on this mixer using a 1/8" to RCA splitter. This does not have an aux 1 bus but instead uses a button to route sounds to the phones/control output. It works as intended wen playing a left or right channel. I get only left or right speakers playing.