Mix 2:1

The Mix 2:1 sums two audio channels down to a single mono output without any power. It can fold the stereo outputs of a console, recording interface or portable player into mono, or blend any two sources while balancing their relative levels.

Each channel has both a balanced 1/4" TRS and an XLR input, plus a ground lift switch to deal with hum and buzz from ground loops. Every input has its own trim control for attenuating a source so two signals match at the output, and the level controls can be bypassed to sum at unity gain. A 180° phase flip helps keep two signals phase coherent when they are combined.

The summed signal leaves through a single XLR output, which can feed a powered speaker or the input of a console or audio interface. It works with line-level signals and with mic-level signals such as two dynamic microphones into one preamp; phantom power must be switched off when connecting it to a microphone preamp.