Adding ambiance to drum tracks with a fake room mic

Using a non room mic as a room mic for drum recordings

Have you ever had a drum recording that lacks ambiance and no room mic was recorded and no matter what you try you can’t get the sound you want out of artificial reverb? It might be possible to use one of the existing tracks in place of a nonexistent “room mic”.

Sometimes you might luck out and have a track that was recorded, but the drummer didn’t play that particular drum. In this case, there were 5 tom tracks, yet the drummer never played the fifth one. This is perfect for a fake room mic. The main difference between a room mic and a tom mic is the distance that the room mic is away from the kit which adds a small delay to that track, of course there is also the room ambiance itself, but we don’t have the luxury with this track which was recorded in a closet sized converted garage with too much sound absorption. The problem with the tom mic is that it also picks up some ugly resonance whenever any drum is hit which in turn makes the tom resonate. Luckily this can be EQ’d out. (Normally all this resonance is something you take out using “Strip Silence”. If you haven’t checked out my tutorial on that, go here…)

Solo the track out and place an EQ plugin on it. Now boost a low frequency peak with a very narrow “Q” and sweep it around until you find the resonant frequency of the tom track. Sometimes tracks will have two main resonant frequencies, often an octave apart. For those non-physics majors, that just means that if the lower frequency resonance is at 110Hz, the other one above it is double the frequency, 220Hz. Sometimes there are more than one frequency and they have octaves. This track had a few. Once I found them, I sucked out a very narrow “Q” at -18dB to help remove the resonance.

To add a small amount of delay can make this track now sound like it was recorded from the other side of the room. Roughly speaking every 1 foot of space is about 1ms of delay, so I am going to add a 12ms delay to the track.

Now the track can be processed like a room mic. I like to strap a 1176 style compressor across the room mic and pound away at it to get a nice aggressive sound which I can then blend in to taste. (If you don’t know how to set up an 1176 style compressor, check out my tutorial here…) This gets me in the ballpark, but I think I would probably add a little ambiance to the “Room” mic to get it a little more realistic.

Here is a demo with the rough drum tracks by themselves without any ambiance, followed by a tom track which was recorded, but the drummer never played. Then the same segment with the Fake room mic, followed by the same segment with the Fake room mic but reverb added to it before the 1176 compression. I pushed the room mic up a few extra dB so it is easier to hear the effect.