When your overhead is mono – the benefits
Mono drum overhead? Why would I want to use such an ancient thing? – you may ask. And that question arises pretty often today, as it did in about the last 40 years. Because for most people, it’s only natural to want those big, wide, stereo drums. A rather awe-inspiring audio image, to hear those impressive drum fills or grooves played on the toms coming from different parts of the stereo panorama. Even the hi-hats or other cymbal hits sound awesome when they imply the three dimensional place they were recorded in. But the truth is not so evident; a single overhead microphone creating a mono drum sound has its very real benefits.
Width is not everything
While wide is nice, sometimes the opposite needed. For slick pop or rock music arrangements, stereo overheads might just be the best way to go. On the other hand, if you want to conjure raw energy instead of the polished sound, try a single, mono overhead. While I wouldn’t mention “unpolished” and those 80s and early 90s U2 records on the same page (wait, I just did), the mono drum sound (along with the bass, of course) does carry kind of a rampant energy.
One of the biggest benefits of keeping the overhead mono is to get the whole drum sound happening right down dead center. It means that your panning gains a lot of freedom. You can suddenly add all of those “dirty pleasure” percussive elements you always wanted to, without having to worry about where to actually place them in the stereo field. There’s something powerful about mono drums coming at you from the middle, and this way, everything else panned around them will not be disturbed by the drum sound either.
Less phase issues = bigger sound
So stereo drums have phase problems? Well, think about it. Recording stuff into two microphones can never be dead accurate, if nothing else, simple because the room reflections hitting the two mics differently. Overheads are no exception either. Then you get to listen to the whole thing from a couple feet away, and the big, wide stereo drum sound disappears. What remains is a smaller sound, because phasing will occur from the two speakers creating their own two different sounds in any given listening environment, too. Once you go mono with the overhead, the two speakers will be pumping out identical halves of your drum sound.
Best of both worlds
What’s even more awesome is, you can actually combine the two ways. Set up three overhead mics; a stereo pair, and your best mono mic for the big centered sound. Now you can go mad with it! An awesome trick that can make a track build and inject drama in the arrangement is to use the mono sound in the verses. When the chorus hits, you switch to the stereo overheads and widen out the sound. If you have patience for details, you can even control the exact amount of the mono/stereo ratio of the overhead sound, all the way through the song.