Drums are one of the hardest things to get right in a “home” recording. Big studios have plenty of outboard gear and a cabinet full of microphones. They often have the leisure of tracking drums to analog tape and later bouncing to digital. In light of this all, you may be surprised to learn drums are one of the hardest things to get right in a pro studio too! Pro engineers get their awesome drum sounds through artistic and tasteful application of effects. Parellel compression is a technique commonly used on “pro” recordings but not often applied to home recording efforts. Running compression is not something you might come up with intuitively, but it is not too hard to set up and the results can be instantly gratifying. This article explores the theory behind parallel compression and gives some compressor settings to get you started.
Theory behind parallel compression
Conventional compression of drums looks something like this:
Conventional drum compression
The drums go through the compressor.
This kind of compression is often called series compression. The term just means the compressor is directly in the line of the signal path. The whole signal is compressed. Don’t think about software, think about having a physical compressor in front of you, it could be a pedal, or rackmount compressor. You run a cable into the input, twiddle some knobs, and run a cable out of the output. The cable coming out of the output is what you hear. That is all that is meant by series compression. Series compression = normal compression.
You can compress your drums this way and there’s nothing wrong with it. Plenty of records use drums compressed via series compression. However, this is an article about parallel compression, so let’s move on to our next picture!
Parallel drum compression
The drums go direct to the output, but a duplicate signal is compressed.
This picture is a little harder to digest at first look. Ignore the bottom Aux->Compressor part for a second. Notice the drum signal is going direct to the output. This is a key element of parellel compression and we’ll be talking about it more. Notice a copy of the drums is going to something called Aux and the aux is going through the compressor. The signal from the compressor is then being mixed back in to the output. It is clear why this is called parallel compression when you see the raw drum signal running next to the aux signal.
That is all the theory you need to know for coming up with great parallel compression on your drum tracks. I’m not the kind of person to just tease you and send you on your way though, so lets dive in to an example of exactly how to set up your compressor to do some sweet NYC style parallel compression.
Note: Why is it called New York style compression? I don’t know, maybe it was popularized in studios in New York City. Don’t ask me, ask google. You don’t need to know the why behind the name to make great sounding drum tracks!
Step 1: The drum submix
The first thing we need is a submix of our drums. This can be stereo or mono based on the needs of your recording. Here are some ways to get your submix:
- Your drum track is made up of loops – If you made your drum track from loops, you likely have a single stereo track with your drum loops on it. This track is your drum submix. Move on to step 2.
- Your drum track is from a VSTi (or other drum plugin) using a stereo out – If you used EZDrummer or some other virtual instrument drummer on a single track, this track is your drum submix. Move on to step 2.
- Your drum track is from a VSTi (or other plugin) using multiple outs – Sometimes it is fun to use things like EZDrummer as though you had miked up a full drum kit with a bunch of mics. Some virtual drum plugins have up to sixteen assignable outs. You could have kick on one track, snare on another, hi-hats on one, etc. In this case, you will want to create a new track to function as the drum submix. Route the output of all your drum tracks to this submix track and make sure they play only through the submix track, and not also through the master output. One way to test if you have this set up correctly is to mute the submix channel. When you mute the drum submix, all drums should get muted. If some drums keep playing, you haven’t routed it correctly.
- Your drum track is a live kit with three mics on it – This is very much like the multiple out VSTi drums, just with a lot less tracks. Create a new track to serve as your submix. Route the kick and both overhead tracks to this submix track (don’t forget to pan those overheads). Test your routing by muting the submix track. If you mute the submix and still hear drums, work on getting the routing fixed before you continue on to step 2.
- Your drum track is a live kit on up to eight or more tracks – This is exactly like the multiple output VSTi. Create a new track to serve as the drum submix and route all the drum tracks to the submix instead of the master out. You should be able to mute just the submix track and all drums should then be silenced. If you mute the submix and still hear drums, please work to correct the routing before continuing.
Be sure to set all your track sends to the submix as post-fx and post-fader if you are using one of the configurations with multiple tracks.
The drum submix is where you try to get your drums sounding great, and natural. You won’t typically want to go for anything unconventional in your submix (but don’t let me discourage you from experimenting with new sounds). Make the submix sound as great as possible by using EQ, reverb, and other effects directly on the submix track, or on the individual tracks going in to the submix. Think about what a great kit sounds like when you’re standing in the room next to it. This is conventionally the ideal sound for the submix.
Step 2: The parallel drum track
Now we need another track identical to the submix, we’ll call it the NYC track. The best way to get this is by creating a new track and setting up a send from the drum submix. You want the send to the NYC track to be post-fx and post-fader from the submix. Make sure the submix goes to the main outputs as well as the NYC track send (unlike the tracks going into the submix which don’t go to main outs).
When you add the NYC track and send the submix to it, your drums should have just gotten louder. Go ahead and lower both tracks (submix and NYC) by -3.0dB. You can test your routing by muting the tracks in turn. When you mute just the NYC track, the drums should keep playing. Muting the submix should still mute all drum output. You may also be able to solo the NYC track depending on the way your DAW (recording program) handles routing. If your DAW handles routing the cool way, soloing the track will sound similar to muting it (the volume will decrease). If your DAW handles routing and soloing the lame way, soloing the NYC track will mute all drum output (just like muting the submix). You can still do great parallel compression with one of the uncool DAWs, but I’m going to assume for the rest of the article that your DAW does it the cool way (and most do). Use common sense where necessary.
Continued in Part 2