Friday, August 28, 2020

Drums - Isolating - Outside/External Bass/Kick Drum Microphone

Video Created by JOEL CAMERON - Transcribed by TOM BOWSER

Why do we want to reduce/eliminate the snare and cymbal leakage into the kick mic/track? Because anything done to the kick drum mic/track (EQ for example) will also be done to the snare drum and cymbal leakage. The result of processing the leakage can cause drums to sound indistinct and can cause strange frequency interactions.

EQ changes to the bass/kick drum will affect the sound of the drum and cymbal tracks present in the leakage which becomes noticeable when these tracks are added to the entire mix.

In this tutorial we compress the external bass/kick drum mic. We will create a send from the snare drum to trigger the compressor on the kick. This will reduce the level of the snare present in the bass/kick drum track. This approach also allows you to keep all the kick/bass drum resonance the outside microphone captures. If you use a Expander / Gate you may lose some of the base/kick drum resonance.

NOTE: If the ATTACK and RELEASE times are to fast you may hear distortion. The distortion will sound like crackling. Increase the ATTACK and RELEASE times to eliminate the distortion. You may also have to reduce the amount of compression by reducing the THRESHOLD.

  1. Instantiate a compressor on the external kick drum mic/track.
  2. Create a pre fader send (click on the PRE button on the track) on the top snare track and send the snare signal to an unused bus.
  3. Name the bus TOP SNARE SEND.
  4. Choose the bus selected in the previous step (TOP SNARE SEND) as the key input of the compressor on the kick/bass drum track.
  5. Enable the SIDE-CHAIN of the compressor by clicking on the tiny key in the SIDE-CHAIN section of the compressor. You can click on the tiny speaker to listen to the side-chain signal (it should be the snare) that the compressor is now using to trigger the compressor.
  6. Set the compression RATIO to 6 or so. Adjust as needed/desired.
  7. Speed up the ATTACK time from the default of 10ms to the compressors fastest setting (turn the ATTACK control fully counter clockwise) or lower to remove the attack/snap of the snare. If you hear crackling/distortion you may have the attack time to fast. Slow it down (turn the control/knob clockwise).
  8. Set the RELEASE at around 250ms or what sounds right for the music. For a more natural sound watch the GR meter to set a release speed that seems natural to the speed of the music.
  9. Adjust the THRESHOLD to the point you are seeing - 6 to -18 of gain reduction. This allows you to keep the sustain of a double headed kick drum (with both heads on while it was tracked).

Any additional leakage left after using this approach may be able to be removed using a LP (low pass filter) or other EQ.

NOTE: The speed of sound is approximately 1100 feet per second so about 1 foot per millisecond. The mic that is in front of the bass drum is probably around 3 feet from the snare mic. When the snare drum gets hit it takes about 3ms to reach the external kick mic.

By keying the compressor off of the snares top mic and then using a pretty fast attack you can compress BEFORE the snare leakage reaches the mic. This allows you to effectively remove or at least significantly reduce the snare leakage in the external kick mic/track.

You will see greater headroom in the external kick drum track allowing you to raise the fader and achieve greater volume of the track in the mix.