Build a Bass Mono/Stereo Rack in Ableton
Generally speaking, the bass channel in a track should be in mono: most subwoofers (not to mention club soundsystems) play a mono signal much better than a stereo one. If you’re making an octave bassline, though, or your bass patch has a lot of high-frequency content in it, you may not want to mix the entire channel to mono. Here’s how to build an audio effect rack in Ableton that allows you to put the lower frequencies in mono without affecting the higher ones.
Drop an Audio Effect Rack onto your bass channel. Open the Chains section and drop two EQ3 plugins into the rack. Rename the first EQ to “Mono”; call the second one “Stereo.” In the mono EQ, turn the “GainMid” and “GainHi” knobs all the way down. This tells the mono EQ to only let low frequencies pass through it, and the stereo EQ to only allow higher frequencies. Open the Macro section of the rack, and map the “FreqLow” knob on both EQs to the first macro knob. This macro will allow you to control the frequency at which the rack separates the signal into “mono” and “stereo.”
Finally, drop a Utility plugin onto the Mono EQ. Turn the Utility’s “Width” control down to zero. This forces all of the low frequencies in the signal into mono, leaving the rest of the signal’s stereo field unchanged. Start playing the bassline, then turn the macro knob; as you turn the knob to the right, the rack will move the point at which it separates the signal into mono and stereo (for a completely mono bass, turn the knob all the way to the right).