High-Pass Filters; Pan Controls; Channel Limiters - Sound Devices 442 Nordic User Manual And Technical Information

442/442N User Guide and Technical Information
It is generally good practice to turn off phantom powering when not using microphones that require it. Phantom
can capacitively couple noise into the mic inputs with poor mic cables. Also, be certain to turn off mic powering
when using ribbon microphones since an improperly wired cable can permanently damage the microphone.
Dynamic
The DYN (dynamic) position applies no voltage to the microphone input.
T Power
T-Powering is a microphone powering scheme used by several European condenser microphone manufacturers.
Today, T-powered microphones are not as common as phantom microphones, but many are still in regular use.
T-power resistively applies 12 V between the signal pins -2 and able T-power for each input. The 442 provides
positive T-power, where pin-2 on the XLR-3 connector has +12 volts relative to pin-3. When using "red dot"
T-powered microphones (reverse polarity T-power) use a polarity-reversing adapter on the input, otherwise
damage to the microphone may occur.
Phantom and T-powering are not interchangeable. Use T-powering only for T-powered microphones.

High-Pass Filters

Each channel of the 442 has an adjustable high-pass fi lter. High-pass (or low-cut / low roll-off) fi lters are useful
for removing excess low frequency energy in audio signals. Wind noise is a common unwanted low frequency
signal and a high-pass fi lter is effective for reducing wind noise. For most audio applications engaging the high-
pass fi lter is benefi cial, since little useable audio information exists below 100 Hz, especially for speech repro-
duction.
The 442's high-pass circuit features an adjustable corner (–3 dB) frequency over a range from 80 Hz to 240 Hz.
Below 80 Hz, the fi lter's slope is 12 dB/octave. At higher corner frequency settings, the slope is 6 dB/octave,
and then below 80 Hz, it increases to 12 dB/octave
give additional roll-off at the 80 Hz setting to reduce wind noise and rumble. The higher settings can be used to
counteract proximity effect of directional mics where a more gentle slope is desirable. The 442's high-pass circuit
is unique because of its placement before any electronic amplifi cation. Most mixer's high-pass circuits are placed
after the mic preamp, where all of the high-energy low-frequency signals get amplifi ed. By virtue of the 442's
circuit cutting the low-frequency signals before amplifying, higher headroom is achieved in presence of signals
with a lot of low-frequency energy.
Where possible, attempt to equalize at the sound source with microphone selection, use of windscreens, micro-
phone placement, and onboard microphone fi ltering. Many microphones have on-board high pass fi lters, and
the high-pass fi lters on the 442 can be used in conjunction with the microphone's fi lters to increase the fi lter's
slope.
The fi lter can be removed from the circuit completely by moving the high-pass control fully counterclockwise.
The high-pass features a pop-up knob so that it can be adjusted easily and then hidden from the mixing surface.

Pan Controls

The pan control routes an input channel signal anywhere between the Left and Right output. The 442 uses con-
stant loudness pan controls, meaning that the signal is 3 dB louder at the full-right or full-left position relative to
the center position. For most applications the channel will be panned either full left, full right, or to the center;
the 442 features excellent "off-attenuation" of the channels in the hard- left and right positions. The pan pot has a
detent in the center position, and is calibrated at Sound Devices for a maximum difference of +/- 0.1 dB between
the left and right output in this position. Since pan is not often used after channel setup, the pan pot is on a pop-
up knob so it can be hidden from the mixing surface during normal operation.

Channel Limiters

The channel limiter acts solely as a "safety" limiter, and is enabled when the output limiters are enabled via the
"LIM" switch on the front panel.
8
v. 5.06 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.
(See Specifi
(See Setup Menu to defeat Channel Limiters
cations). The purpose for this compound slope is to
entirely.) In normal operation, with