Most commonly, toms have been treated with noise gates and expanders to help cut down on cymbal bleed in the tom mics. Unfortunately, this doesn't really solve the problem when a cymbal is still ringing out while a tom is struck and so when the tom mic becomes unmuted the volume of the cymbal increases because it is already bleeding through the mic. The common solution to fix this problem is by replacing the tom hits, but there’s a much more clever way to solve this using an automation trick if you are willing to put in some time and effort.
- You will need a low pass filter inserted on the tom channel with its frequency automatable.
- Start with the frequency as low as it will go which will effectively mute the entire channel.
When the tom is hit, create an automation point at the transient with the frequency set to 20 khz.
Shortly after the transient, you can automate the frequency down to ~ 400 hz depending on the tom. Now that the transient is done, we are removing all the treble frequencies from the channel while keeping the low end ring out as the tom sustains.
After the tom has had time to sustain, automate the frequency back down to as low as possible until the next hit comes along.
Experiment with how fast the frequency moves to achieve the desired effect.
This trick is very effective on all genres of playing, and is flexible to work in almost any mic setup and situation.