[HAM] How to mic a Leslie (again)

[Dave Bishop]

Here is an extended quote from the May 2008 issue of Keyboard Magazine about 
how to mic a Leslie.  I have some disagreements with it, but I'd like to 
know what the rest of you think:
Dan [Goldstein],
What's the best way to mic a Leslie speaker? Are there different techniques 
for stage and studio?
-Bill

Bill,

Whenever you set out to mic anything, you have to consider what the 
microphone hears, versus what your ears hear. The amazing sound of a Leslie 
speaker is a complex blend of the Doppler effect combined with the 
reflections off of the walls of the room that the Leslie is placed in. A 
Leslie speaker's spinning horn and rotor throw audio out in only one 
direction at a time, and as they spin the sound moves from one ear to 
another and back again. When you set out to mic this cabinet, you want to 
capture that effect and recreate it in your recording.

The most common method when miking a Leslie is to stick one microphone on 
the top horn and one on the bottom rotor. However, this is not the way we 
actually hear a Leslie. If you mic this way, the sound is heard loudest when 
the horn or rotor is pointing directly at the microphone, and then becomes 
very quiet when the horn or rotor is pointed in the opposite direction, 
which is contrary to the actual listener experience of the Leslie. This 
miking technique can create an exaggerated tremolo volume effect that may be 
unpleasant and unrealistic, and give the audience the impression that the 
Leslie is running at half speed. Instead, a great way to mic a Leslie, 
whether on stage or in the studio, is with four microphones: two on opposite 
sides of the cabinet, panned in stereo, set up at the top louvers, and two 
on opposite sides of the cabinet, panned in stereo, set up at the bottom 
louvers. Yes, this will require four mixer channels and four tracks for 
recording, but the end result will really capture the sonic depth of the 
speaker. Careful blending of the rotor bass mix and the treble horn mix will 
give a very professional, realistic result.

In classic wood Leslies, such as the 122, 147, or 145, and in every solid 
state Leslie I've encountered, the horn and rotor are not actually centered 
in the cabinet. Instead, they are both off on the left side (when facing the 
front of the cabinet) to make room for the amplifier and motors. Therefore, 
for best results, you'll want to place two of the microphones in front of 
the cabinet, several inches to the left of center, and the other two 
microphones in back of the cabinet, lined up with the first set. It's best 
if the back covers are on the Leslie to provide a consistent tone and volume 
for the front and back of the cabinet. Adjust the microphone trim on each 
mic channel for consistent volume between each pair of mics.

In a pinch you can use one microphone on the upper horn, as the upper horn's 
tremolo effect is often less exaggerated with a single microphone. The lower 
rotor can sound pretty bad with a single mic, especially when the Leslie is 
in slow/chorale mode. Whenever possible, however, take the plunge and use 
all four mics!

When recording in the studio, it can be an effective technique to back the 
microphones away from the speaker cabinet somewhat to capture the Leslie 
reflections and room tone. In a live setting, you'll want to have the mics 
very close to the cabinet to eliminate background noise.

Finally, since Leslies do not produce very high frequencies, almost any 
quality dynamic microphone can be used to mic a Leslie with great results!
-Dan



Regards,

Dave Bishop