I have been recording drums for quite a few years and during all those years I basically stuck to using 3 mics to capture the sound. The premise, as I see it, is that you only have 2 ears so 2 mics in stereo should be able to reproduce what you hear in real life. So if it sounds good in person, it should sound good with 2 mics. The 3rd mic comes into play to help with the “boom” you “feel” when you listen to music. You dont necessarily get that in through your ears. You can feel it in your whole body. That is hard to capture with just the 2 mics reproducing what you hear. I use the 3rd mic for the kick drum on the drum set. This captures the boom and also helps me match levels with a bass player or bass recording that was most likely done at a different time from when the drums were recorded.
Recording with 2 mics dows have its drawbacks. You get a broad sound with no focus on a particular part of the drums set which means when you want to bump a part up in the mix you can. You have to rely on the drummer to play his parts knowing that HE will have to be the one “mixing” as he plays. Need the toms to stand out during a fill? Gotta hit them a bit harder. You think the cymbal crashes are too loud? The drummer needs to alter his playing to make it work. Actually this is a good thing as the drummer should know how to do that for live performances anyway!
One of the other major drawbacks and the main focus of this blog post, is the room. Unless you have a professionally designed room, you will have to deal with the less than perfect artifacts that a room can create when recording drums. When you make a sound in a room, the room reacts and duplicate that sound. Sometimes it’s a pleasant sound. Mostly, in home studios it’s crap! That’s why we put up room dividers & wall treatments to help diffuse that sound. 1st preference would be a great sounding room. 2nd preference would be NO room sound at all so we could add digital room emulation after we track the sound. In my home studio i have been keeping the mics as close to the drums as i can so that the sound of the drums is much louder than the subsequent sound of the room that is echoed 5-10 ms later. That “room” sound is always there. Being that my room is simply a bedroom, it sounds bad. That has been my challenge for years. If I move the mics too close to the drums, I lose the natural sound of the drums. It can sound like one drum is only in your left ear and some are only in your right ear. The best sound of a drums set is one that is balanced naturally and sounds just like it would if you were a few feet in from of it, hearing all drums and cymbals in a nice blend. To do that you need the mics placed away from the drums. Hence the dilemma. The room then comes into play again! Let me try to make this clearer. Your brain can hear very very short differences in time delay. Sometimes its only perceptible but you can still hear it. So the closer you put the mics to the drums, the further they are from the wall. That increases the time it takes the sound to travel from the drum, to the wall and back to the microphone. It may be only 10 ms but you CAN hear that in the mix. You can literally hear the “room”. Did you ever hear a song that you thought sounded like it was recorded in a small room or a garage? That’s the mics picking up the sounds bouncing off the walls.
Enter the boundaries! I got to thinking that if I really like the sound of the drums but don’t like the room and I cant eliminate the room, the only thing left is to make the delay between the drum hit sound hitting the mic and the delay sound coming off the walls as short as possible so that we can even perceive it! I thought, “what if I put the mic up against the wall so there is quite literally almost no delay at all?” The sound recorded would only be the drums! I took a pair of mics and pointed them directly at the was about 1/2” away from the wall. WOW!! NO delay! Sweet! I can record in a crappy sounding room and hear far less of the room! Yeah! There is still sound coming from the opposite wall but I am trying a few things for that. I found that people make microphones that suit this technique perfectly. They are call boundary mics and are used on ceilings, floors and walls. I am searching for a pair now!