Saturday, June 4th, 2011 | by matthew mcglynn
What is flutter echo?
It is a series of rapid, repeated reflections caused by soundwaves bouncing around between parallel reflective surfaces. It can happen in any untreated space, but any smallish room with a hard floor is especially susceptible to it.
My den has it bad. Standing near the center of the room, I recorded a series of handclaps. This is what a flutter echo sounds like:
I used compression on this sample to bring out the sound of the echo. It sounds like a metallic ringing. In this particular room, the echo actually moves around, up and away, into one of the corners as it fades.
(In case there are any mic nerds in the audience 😉 , I must note that I recorded this with an Avenson Audio STO-2 omni condenser, pointed at the ceiling in the center of the room.)
If this sound is present in your tracking room, it will color the recorded tracks. And if it’s present in your mixing room, you’ll be fighting to EQ out a sound that isn’t in your mix, but only in your room.
Here’s the same flutter echo sample as above, at half-speed. You can more easily hear the individual echoes this way:flutter_echo_slow.mp3
If you have flutter echo, how can you fix it? In short, you need to break up the parallel reflective surfaces. Acoustic panels or foam, diffusors, drapes, furniture… there are a thousand ways to do it, and a thousand acoustic treatment vendors willing to help. The nice thing about fixing acoustic reflection problems is that once they’re gone, all your gear will sound better.