Here goes - I just bought a couple of American Audio/American DJ 19MXR DJ Mixers. I have them plugged in and MIXXX recognizes it. I did not find a mapping for this particular model in the forums here, so I used the MIDI learning wozard to map the Volume Fader 1 and 2 to the software Decks 1 and 2. Also mapped crossfader, headphones, gain, EQ, etc… not quite everything, but enough to get me up and running to test it out.
Here’s the issue: I can have tracks playing on channels 1 AND 2. If the volume fader for channel 2 is up on the mixer, then I can use fader 1 to control the volume in MIXXX for deck 1, and channel 2 the same. If I lower the volume for fader 2, however, then the entire output mix disappears. The MIDI signals are all still being sent and I can see the faders/knobs all move in MIXXX regardless.
Its almost as though channel 2 is acting like a hard-wired master volume, although I don’t think that’s the case. I have verified that fader 2 is NOT assigned to the master knob in MIXXX (the master knob does not move in conjunction with fader 2).