How to produce great-sounding drum tracks - Gating
This is a part 4 of the tutorial on how to process individual raw drum tracks into finished product. Make sure to read all the parts.
Part 1: Introduction / Approach
Part 2: Editing
Part 3: Track Time Alignment
Part 4: Gating
Part 5: EQ
Part 6: Phase Alignment
Part 7: Compression
Part 8: Ambiance (Reverb)
Gating of drum tracks
Gating is a process in which a processor (a plugin) reduces or completely removes sound under a certain sound level (threshold). For example, if we set the threshold on the gate to -20db, when the sound falls under -20db, it will be muted.
We are going to gate snare drum and the kick drum, but using different techniques.
Snare Drum Gating
We have 2 microphones for the snare: top head and bottom head. The idea is to leave only the rim shots and some medium notes for the top mic and leave the fine ghost notes for the bottom mic. If no low-cut (hi-pass) filter was used on the snare, we would first insert a lowcut filter on the snare tracks in order to remove most of the kick drum sound, as well as possible low-frequency rumble.
Use a sharp low-cut filter (36-42db per octave) and set it around 150Hz. Listen to each track solo-ed to make sure you are not removing any “body” of the snare sound.
Top Snare Mic:
Insert a good quality dynamics plugin at the top of the chain on snare 1 track. If you don't know how to operate a gate, I suggest that you familiarize yourself with appropriate literature. First you need to observe at what levels most of the snare rim shots happen. Then you need to set the threshold below that level, so that you only cut out the unwanted noise, but leave the snare hits unaffected. The gate will also help tighten up the snare sound if there is ringing going on. Move the threshold up, until you notice that the noise between the rim shots has gone away and you can only hear clean rim shots.
Attack should be set to the minimum value.
Release: adjust it to the minimum if you want a shorter and tighter sound, or to longer if you want to drum to decay more naturally. Just keep in mind that if you set the release for too long, sounds from other drums will start to sneak in.
The range nob is used to indicate the level to which the gated noise should be reduced to. If set to negative infinite, it will completely mute the background sound.
And lastly and very importantly, hold nob will allow us to sculpt the length of rim shot decay. By setting it to around 100ms, it will allow for natural resonance of the rim shot. If your plugin does not have the “hold” function, then you will need to adjust the “release”, so that the shots decay naturally. Play around with it to get the sound you like.
You should now have a clean top snare drum track. Success!
Be careful not to negatively affect the sound quality of the snare. You should adjust all of the parameters carefully.
Bottom Snare Mic:
Remember to first insert a low-cut filter. You can apply some gating to bottom snare mic as well, but you have to be very careful with the threshold, so that you don't cut out the ghost notes, which would partially defeat the purpose of having the bottom mic. Observe the input meter to see at which levels ghost notes, rim shots and noise happens. That will indicate how well you can utilize the gate. We may not be able to fully remove the noise (without removing the ghost notes), which is ok. This mic will be lower in the mix anyway. We will later shape the amount of rim shots we want to get from the bottom snare drum mic.
Kick Drum Gating:
Now, I am going to let you in on a little "secret" on how to successfully gate the kick, as the traditional approach will most likely not work well.
Unlike snare, gating a kick drum is particularly problematic. The problem is that traditional gating will produce a whole lot of artificial clicks and pops and possibly lose some of the quieter kick notes. Traditional use of the gate will not produce a natural kick sound. I have come up with a system which will completely remove the unwanted noise on the kick, while leaving the rest sounding totally natural. If done properly, you will think that the kick was recorded on its own! Read on...
We are going to use a system of side-chain gating for the kick drum tracks. For this to work, you need to have software that support “side chaining”. Refer to your DAW user manual. I was relieved when Steinberg introduced this feature to Cubase and Nuendo. Logic has had this forever. Let me first explain what we are going to do and then step by step “how to”:
We are going to use a duplicate of Kick 1 track with heavily applied gate “clicking artifacts” to open a gate on the Kick 1+Sub Kick tracks, but slightly before the kick drum strokes. This will allow for clear, unaffected notes to come through in their entirety.
Here is how to do it:
1. You need to duplicate your “Kick 1” track. Lets name the duplicate “Trigger Kick” and place it above the “Kick 1” track.
2. Create a mono group and name it “KICK GROUP”.
3. Route “Kick 1”, “Sub Kick” and "Trigger Kick" tracks to the KICK GROUP.
4. Zoom in on the Trigger Kick and Kick 1 and shift the Trigger Kick to the left, so that it is ½ of wave cycle ahead of the Kick 1. See picture bellow.
5. Insert an EQ on Trigger Kick and select a hi-cut (low pass) filter at around 200Hz in order to cut everything above the bass range (this will remove snare, cymbals etc.). See the picture bellow.
Now that we have just the bass portion of the kick sound coming through, we can be sure that only kick drum strokes will trigger the gate we are about to set.
6. Insert a gate on Trigger Kick track. Set the range to infinite, attack to min,hold or release to around 15-20ms. While listening to solo Trigger Kick, increase the threshold until you are getting artificial clicks on every single stroke. You want the sound to be like an electronic kick “tzc tzc tzc”. Make sure that quieter notes are creating those short “tzc” clicks and that there is no noise between the hits. If you need an electronic-sounding kick, you've got it now.
7. Your Kick 1 and Sub Kick tracks should be routed to KICK GROUP. Insert a Gate on KICK GROUP that has a side-chain feature. Switch the track side-chain ON.
8. Send an AUX signal to side chain gate on Kick Group, as in the picture bellow:
Make sure to click on the prefader button (little button lit orange in the pic above). This way the signal will be routed to the side chain gate regardless of the fader position on Trigger Kick track.
Set the level of send signal to 0db and then lower the channel fader on Trigger Kick to the bottom.
So, what's happening now is that the signal from the Trigger Kick is going directly into our KICK GROUP gate. We can not hear the Trigger Kick anymore, but it is going to trigger the gate for the KICK GROUP. Since we shifted the Trigger Kick ahead of the 2 kick tracks, the gate is going to open right in time to let the sound of KICK GROUP come through without affecting the transients.
9. We need to set the parameters of the KICK GROUP gate now. Make sure that you have solo-ed all 3 kick tracks. Set attack to minimum, hold on minimum and release to minimum. If you have “peak-RMS” nob, set it up “peak”. If you have range nob, set it to infinite (maximum). Lower the threshold to minimum, while listening to the play back. Make sure to be getting all of the notes without any clicking artifacts. You can control the length of the kick strokes, by increasing the release or hold.
There- you have the perfectly clean kick track!
Lets continue with EQ of Drum Tracks.