M-Audio Microphone, User Manual

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invariably prefer the sound of solid brass. Needless to say,
we use solid brass backplates in all M-Audio mics.
The spacing between the diaphragm and backplate is
critical. In order to avoid problems with barometric
pressure, the spacer ring has a break in order to allow air
to move freely between these two components. We
precision drill approximately 100 extremely fine holes in
the backplate, some going all the way through and some
only going partially through. This combination further
allows the appropriate amount of damping for the
diaphragm.We then lap the surface in order to ensure that
it is completely flat.This operation requires such precision
that we measure the results not with a ruler, but with
reflected light.
This level of precision is only possible due to modern
computer-controlled manufacturing techniques. The
important distinction is that these operations are
programmed and supervised by human technicians at
every step. All-in-all, there are several hundred precision operations that go into making each of
our solid-brass capsules. That s more than the number involved the crafting of the average Martin
guitar and we re talking about something the size of a 50-cent piece.
Patterns
The term
polar pattern
is used to describe the response of a microphone to sound sources from
various directions. Each type of polar pattern has its own place and usage in the recording process.
Note that the classic polar pattern definitions apply most accurately when sounds hit the
microphone on axis that is to say, approaching perpendicular to the planar surface of the
diaphragm. In general, microphones tend to become more directional in focus as frequencies
increase. Put another way, capsules are generally less sensitive to high frequencies off axis. This
phenomenon is typically less significant in medium capsules than in large capsules.
Cardioid pattern
The
cardioid
is the most common polar pattern found in
microphones. The name derives from this pattern s
resemblance to a heart shape. Cardioids are unidirectional,
meaning that they pick up sound primarily from the front
of the capsule. The back of the capsule rejects sound,
allowing the engineer to isolate the signal source from
other performance elements or background noise. More
noticeable in larger capsule designs, cardioid patterns
typically exhibit a
proximity effect
a boost in low-mid
frequencies as the proximity between the source and mic
increases. Proximity effect is also more prominent with
both larger capsules and lower frequencies.
Omni pattern
As the name implies, the
omni-directional,
or
omni
pattern,
picks up sounds equally well from all directions. Omni is
used to capture room resonance along with the source,
thereby yielding a more open sound compared to the more
focused quality of cardioid. Omni is great for vocal groups,
Foley sound effects, and realistic acoustic instruments
assuming that acoustic space of the recording environment
is desirable.
screw/contact
resonator disk
disk spacer
backplate screws
diaphragm
w/ mounting ring
ring spacer
center spacer
backplate
registration pins
backplate spacer
backplate base
The major components of a large M-Audio condenser
capsule are a solid brass backplate and an ultra-thin
evaporated gold diaphragm
Choosing & Using Microphones
6
30 cm (1')
7.5 cm (3")
0.6 cm (1/4")
10
5
0
-5
--10
50 100 200 500 1k 2k 5k 10k
Frequency (Hz)
R
e
lativ
e
le
v
e
l (
dB
)
The proximity effect causes increased output in
the low-mids as distances between the mic and
source increase
Cardoid patterns are most
sensitive on the side of
the capsule
Omni patterns are
sensitive to sound from all
directions