The cartridge
Directional microphones Type 4011 and 4012 uses a 19mm diameter
prepolarized pressure gradient condenser-microphone cartridge with a first
order cardioid pick-up pattern. The diaphragm is of PVDF with a vaporized
layer of aluminum. This material is non-hygroscopic, i.e. it does not absorb
water, and is highly resistant to the most aggressive kinds of humidity.
The microphone housing is German silver. The large spacing between the
diaphragm and the back plate in this cartridge makes the microphone highly
insensitive to temperature influence. The microphone cartridge is designed to
have a linear on-axis response from 40Hz to 20kHz ±2dB measured in 30cm
distance (see Fig. 4). Great attention has also been paid to the microphone’s
off-axis performance during the design process (see Fig. 4). The diaphragm is
protected from dust by an acoustical transparent net behind the front
protection grid and inside the back port of the cartridge. For optimum stability
the microphone cartridges have undergone a special pre-aging process which
releases all tensions in the materials and stabilizes the polarization voltage.
The preamplifier
Types 4011 and 4012 are acoustically identical, but differ in their preamplifier
powering system. The 4012 is powered with 130V via the HMA4000 High-
Voltage Microphone Amplifier and has a modified 4-pin XLR-connector (see
Fig. 1 for pin designation). This special powering system enables the microphone
preamplifier to handle approximately 10dB higher sound pressure level than
similar microphone types powered through conventional P48 systems (4012:
168dB SPL peak and 4011: 155dB SPL peak). Both the 4011 and the 4012
together with the HMA4000 are transformerless. The 4011 is powered via a
standard P48 system and is equipped with standard 3-pin XLR-connector
(see Fig. 2 for pin designation), but has an attenuator switch built into the
2
Technical Description
User’s Manual
