EarthQuaker Devices Four to One Mixer Compact 4-Channel Signal MixerEarthQuaker Four to One Mixer 4 Channel Audio Combiner with Independent Volume and Phase Switches The Four to One mixer is a simple and compact 4 channel mixer with independent level controls and selectable phase for each channel. This was primarily designed to be used with our One to Four Splitter to create 4 parallel signal paths, but it can be used just about anywhere you need to mix four different sources into a single output with your unique