Glossary of Terms
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Low shelving filter
- An equalizer circuit that cuts or boosts signal below a specified frequency, as
opposed to boosting or cutting on both sides of the frequency.
Makeup gain -
A control that allows the overall output signal to be increased in order to compensate
(“make up”) for the gain reduction applied by the compressor.
Mic level
- Refers to the very low level signal output from microphones, typically around 2 millivolts
(2 thousandths of a volt).
Mic preamp
- The output level of microphones is very low and therefore requires specially designed
mic preamplifiers to raise (amplify) their level to that needed by a mixing console, tape recorder, or
digital audio workstation (DAW).
MOSFET –
An acronym for “Metal Oxide Semiconductor Field Effect Transistor,” an advanced type of
solid-state FET.
Negative feedback
- Not just something to fear on Ebay. Negative feedback is a design technique
whereby a portion of the preamplifier’s output signal is reversed in phase and then mixed with the
input signal. This serves to partially cancel the input signal, thus reducing gain. A benefit of negative
feedback is that it both flattens and extends frequency response, as well as reducing overall
distortion.
Noise floor
- Unwanted random sound (noise) added by an electronic device.
Patch bay
- A passive, central routing station for audio signals. In most recording studios, the line-
level inputs and outputs of all devices are connected to a patch bay, making it an easy matter to re-
route signal with the use of patch cords.
Patch cord
- A short audio cable with connectors on each end, typically used to interconnect
components wired to a patch bay.
Peak reduction -
A synonym for compression or limiting.
Ratio -
see “Compression Ratio”
Release time -
The time it takes for a signal to return to its initial (pre-compressed) level. If the
release time is too fast, "pumping" and "breathing" artifacts can occur, due to the rapid rise of
background noise as the gain is restored. If the release time is too slow, however, a loud section of
the program may cause gain reduction that persists through a soft section, making the soft section
inaudible.
