Time Alignment & the Drum Kit

If you mix on a digital console, this post is REALLY important.  Unless you’ve been mixing under a rock, I’m sure you’ve heard about time aligning your drum mics.  I’ve been reading about others’ results with this for a long time but have never been faithful to time align every time I mix because most of the samples I’ve heard of before and after have been less than convincing.  My prejudice, and maybe yours as well if you’ve heard similar samples, is that time alignment on the console using channel delays is a 2% mix improvement step, not a 15% or larger mix thing.  Because of our intense pace at Kensington, it has been hard to have the discipline to time align every time.

When I was mixing on a PM1D every week, I made an effort each time to time align by ear and just slide back the snare, hat, and tom mics back to the overheads by anywhere from 2-6 milliseconds.  The difference was noticeable but still what I would consider a minor “glue” thing – certainly not earth-shattering.  When I moved to the Venue, I kind of set the time alignment stuff aside for a few months in order to focus on more core tasks and efficiencies.  A few months ago, I began to revisit time alignment and this time, for some reason, the results really were a game changer.  I’m not sure exactly what to attribute that to, but I can share some tips on the overall approach I’ve settled on that seems to give the best results.  If you haven’t tried this, I would suggest you should and see if it makes as big a difference for you as it did for me.

My goal in time aligning is so that the tone of a drum (let’s use the snare as an example) will sound nearly the same when listening to the close mic as when the overheads are added in.  What I found a few months ago in the run up to Easter was that it was bothering me to get a snare sound I liked with the close mic and by the time the overheads were where I wanted them that tone was destroyed.  Pull the overheads out and the snare tone would go back to where I wanted it.  What I found was that I was hearing a combination of overheads with too low of a high-pass filter setting and comb filtering between the close mic and overheads.

I should preface that there are two different philosophies for overheads on a drum kit.  The first is to place them strictly as cymbal mics.  For some music styles or drummers, this is necessary in order to get the expected mix results.  The other option is to use them as an overall kit mic that just so happens to have cymbals as a focus point.  In this scenario, the high-pass filter will likely be set lower than it would for cymbal micing applications – probably 100-200 hz instead of 500 hz plus for cymbals.  Another important part of the kit mic approach is using mics in a X-Y pattern over the kit.  I go back and forth between a Rode NT4 and Shure KSM141s on the Shure stereo adaptor bar.

The first step to the results I want is to use the overheads as kit mics and still set the high-pass around 250 hz.  This allows the overheads to still be the glue for the kit but the close mics to provide the “in your face” body of the sound.

Next, each mic is delayed back to the overheads.  I’ve found the easiest way for me to do this is to have the drummer give me a quarter notes on each drum and record that into PT.  (If you don’t have PT, instead of this technique, just go drum by drum and have the player give quarter notes while you dial each mic in)  Once in PT, I zoom in closely on those hits and measure the difference in time between each of the close mics and the overhead.  The results are usually somewhere between 40-160 samples.  (You could also do this with milliseconds but because PT & Venue can go to samples resolution, that’s what I use)  When you have it right, its the first time in my life that there is a negligible difference between the tone of the close mic and once you put the overheads in.

Next time I’ll post some samples that will hopefully convince you.  This topic has been written about all over the web so if I’ve piqued your interest, start digging into it and feel free to ask questions here.