You truly never stop learning, and this is the case with me and Expanders. I somewhat dismissed them for a long time even though I always knew what they did, until a drummer & engineer friend told me I âmustâ use an expander on drums, specially if blended in via a Bus.
And now I canât do without. Thereâs just a subtle clarity that you get by gently ducking down stuff that mic pic up.
My drums recording setup at the moment is quite rudimentary as in I'll have a mic in front of kick, a 57 on the snare and then 2 overheads that capture hh, toms and cymbalsâŠ
Anyway, continue reading if you want my 2 Cents on the topic.
What Is An Expander?
We should start from this. We can essentially say itâs the opposite of a Compressor?
On a Compressor you set a Threshold so that anything going above is pushed down based on the Ratio you set.
On an Expander, you are pushing down anything going BELOW the Threshold, based on the Ratio you set. Thatâs why itâs used a lot in live concerts where you might need to clean up background noise, reduce mic bleed but also add âpunchâ and vigour, energy, sparkle, dynamism!
So yes, a Gate would be an Expander that allows nothing below the threshold through.
Remember sometimes mixing is about âremovingâ more than âaddingâ!
The Theory: Why Use an Expander on the Drum Bus?
Enhance Transients: By lowering the level of quiet sounds so theyâre even quieter, expanders naturally emphasise the loudest, punchiest parts of the hits (like the initial snap of the snare or the beater on the kick).
Reduce Bleed and Room Mud: An expander drops the level of room noise, cymbal bleed, or reverb tail that occurs between heavy drum strikes, resulting in a tighter, more focused kit. All that but without becoming a Gate, just a gentle reduction that maintains and improves the dynamic range without âremovingâ too much.
Dynamic Contrast: Rather than just increasing the volume of the peaks, expansion increases the contrast between the loudest and quietest elements, making the drums sound much more aggressive and lively.
Step-by-Step Settings
To get the best results on a drum Bus, you want to be very subtleâextreme settings can swallow ghost notes or abruptly cut off cymbal decays.
Start with a Low Ratio: Set the ratio between 1.1:1 and 1.5:1. You only need a gentle downward push, not a harsh, aggressive gate.
If like me you use LogicProâs own Expander just know that the Ratio is flipped, goes from 0.5:1 (max ratio) to 1:1 (bypass).
Dial in the Threshold: Pull the threshold down slowly until you are only attenuating the quietest tail-ends of the hits and allowing the main transients to trigger full volume.
Use Fast Attack Times: Set the attack as fast as possible (around 1â3 ms) so that it catches the initial hit right as it happens.
Tweak the Release: Set a medium-fast release (around 40â100 ms). If itâs too slow, it will leave the volume âduckedâ after a loud snare hit. If itâs too fast, it will distort and cause a stuttering effect on the low-end.
Adjust the Range: Keep the range or depth control relatively conservative (between â3 dB and â6 dB). This ensures the expander only lowers the volume of the bleed slightly, keeping the overall mix natural.
In my humble opinion this doesnât affect your ability to add compression and EQ on each drum mic. I typically mix each track and I listen to the kit as a whole, of course EQ allows you to clean up and bring out the frequencies you want each track to focus on. Once done I send some signal from each drum track to my Bus with the Expander, I actually often find myself sending more signal from kick and snare than the overheads. This gives me clearer (+ all the adjectives used above) kick and snare and I can leave my overheads as they are or send 30/40% of their signal to the Bus too (kick & snare being 60/70% through the Bus.
I donât do any Parallel Expansion for example but, below are some reasons why you might want to (also depends on the genre, I mostly do pop/rock songs, blues songs, or instrumental fusion or piano stuff so I donât need HUGE kicks).
Advanced Techniques - Taking It A Bit Further
Parallel Expansion: Instead of putting the expander directly on your main drum Bus, create a parallel auxiliary (aux) track. Use heavy expansion on the parallel track to crush and isolate the punch of the kick and snare, and then blend this aggressively punchy track underneath your dry drum Bus.
Multiband Expansion: If your cymbals or room mics sound too harsh, use a multiband expander to apply expansion only to the lower-mid frequencies. This helps tighten up the âmudâ and âboxinessâ of the toms and kick, while leaving the high-end sparkle of the overheads untouched.
The End
As always thanks for reading, gimme your comments and feedback. What do you do in this scenario?
Beginners, was this clear enough for you? Did you catch the difference with a Compressor or a Gate?
If not, reach out, thereâs a Subscribers Chat that is free where you can ask questions and get advice or we can take it further with a video call so you can ask me stuff for an hour (or more!)