Miking Techniques
Multiple Mic Techniques:
XY
This stereo technique is used when you want to avoid any
possible phasing problems associated with a spaced stereo
pair. Two directional mics (usually condenser mics) of the
same brand and model are placed with the grill (and thus,
the capsule) of one mic over the grill of the other, at
an angle to each other. The overhead result looks like an
upside down V. This exhibits very good stereo imaging, when
the two recorded tracks are panned hard left and hard right.
The angle of the two mics is generally between 90 and 135
degrees.
Bloomlein
This is basically just an XY stereo technique using two
figure-eight (bi-directional) mics, instead of directional
mics. Using bi-directional mics just picks up more of the
ambient sound of the room. This is often used in recording
drum sets, and was used on many classic rock recordings.
Spaced pair
Just how it sounds. Two identical condenser mics spaced
a certain distance apart, both placed at the same distance
from the sound source. This is used often for large groups,
or sections of instruments or vocals. It's also used for
overhead cymbal miking on drum kits. The spaced pair can
be close to the sound source or further away. This technique
can achieve a great stereo sound when panned hard left and
hard right, but it can also cause some phasing problems
between the two tracks. In order to lessen this chance,
you can place the mics at a 3:1 ratio. 3 feet apart for
every 1 foot away from the sound source. The closer you
can get to this placement, the less phasing problems you'll
experience. This is not always practical, however.
Mid-side
A technique using a bi-directional or stereo mic, and a
directional mic with the grills close together, as on the
XY technique. However, the figure-eight pattern is set to
face left and right, and the directional mic is pointed
straight forward. Unlike the other stereo techniques described
here, this requires an external transformer or active matrix.
Some upper end microphone preamps have this feature built
in. By adjusting the balance of Mid to Side in the external
controller you can adjust how distant or close the mics
sound, without actually having to move the mics. Of course,
the drawback is that you need an external device or a mic
preamp with Mid-Side capability. Most recording studios
(especially home recording studios) do fine using just the
XY, spaced pair, and bloomlein stereo techniques.
