About Condenser microphone

1. CONDENSER
MICROPHONE
Submitted By:
Gyan Jyoti Gogoi.
POW/15/ET/029

2. WHAT IS A CONDENSER
MICROPHONE?
While dynamic microphones are popular for
stage use, due to their rugged construction,
condenser microphones have always been the
preferred type
for studio
recording.

3. WHAT IS A CONDENSER
MICROPHONE?
# A condenser microphone capsule with a
gold sputtered Mylar diaphragm.
# The back plate consists of solid brass
with a hole pattern that must be drilled
with extreme precision for consistent
sound.

4. HOW A CONDENSER
MICROPHONE WORKS:
 The British call them “capacitor microphones” – and
for a reason, too. You may remember from physics
class that a capacitor is essentially two metal plates
in close proximity. The closer they are, the higher
the capacitance
 A condenser capsule is constructed similarly. It
consists of a thin membrane in close proximity to a
solid metal plate. The membrane or diaphragm, as it is
often called, must be electrically conductive, at least
on its surface. The most common material is gold-
sputtered Mylar, but some (mostly older) models
employ an extremely thin metal foil.


5. HOW A CONDENSER
MICROPHONE WORKS:
 When sound waves hit the diaphragm, it moves back and forth
relative to the solid back plate. In other words, the distance
between the two capacitor plates changes. As a result, the
capacitance changes to the rhythm of the sound waves. Voilà, we
have converted sound into an electrical signal.
 The capsule signal itself, however, is much too “fragile” to be
connected to other pieces of gear. The condenser capsule’s
output voltage is actually quite high, but it produces almost no
current, because so little energy is stored in this small capacitor.
It requires what is called an “impedance converter”, a circuit that
buffers between the capsule and the outside world. The
impedance converter makes the signal more “sturdy” by making
more signal current available.

6.  Condenser microphones therefore require external
power. This could be inconvenient in the old days,
but today just about any microphone input offers
P48 phantom power – a Neumann invention, which
has become the international standard (see box
“Powering Condenser Microphones”).
Due to their low-mass
diaphragm, condenser
microphones have
superior transient
response.

7. SUPERIOR SOUND QUALITY
 Due to its extremelylow mass, the diaphragmof a condenser
microphone can followthe sound waves more accurately than that of a
dynamicmicrophone witha (relatively) heavy moving coil attached.
Condenser microphones, therefore, offer superior sound quality. Of all
microphone types, condensers havethe widest frequency response and
the best transientresponse (transients are fast bursts of energy, e.g. the
attackof a drum or the “pick” of an acoustic guitar). Also, condenser
microphones usually offermuch higher sensitivity(i.e. output) and
lower noise thandynamicmicrophones.

8. POWERING CONDENSER MICROPHONES
 Condenser microphones require external power for their
internal electronics. Early specimens – Neumann has produced
condenser mics since 1928! – had tube electronics, which
were powered by an external PSU box the size of a brick.
This was inconvenient in many ways, especially when many
microphones were used at the same time, because each type
required its own PSU box and a dedicated multipoint cable.
 When transistor technology took over in the late 1960s,
Neumann invented a standardized scheme to power condenser
microphones directly from the mixing desk, without the need
for external PSU boxes and multipoint cables. P48 phantom
power works with 48 volts, supplied via the usual 3-pin
microphone cable, and it does not affect dynamic
microphones that do not require external power. Due to its
convenience, P48 phantom power soon became a world
standard.

9. POWERING CONDENSER
MICROPHONES:
 More recently, tube technology has
become popular again as a “vintage”
sound alternative. Modern day tube
condenser microphones, just like their
ancestors, require an external power
supply, because tubes consume more
energy than phantom power is able to
provide.