Noise floor will be a quiet hiss, which is the thermal noise generated by bouncing electrons in the transistor junctions. The lower the noise floor and the higher the headroom the more usable dynamic range a system has.
Parametric EQ
A “fully” parametric EQ is an extremely powerful equalizer that allows smooth, continuous control of each of the primary EQ parameters (fre- quency, gain, and band-width) in each section independently. “Semi” parametric EQs allow control of fewer parameters. Usually frequency and gain (as they have a fixed bandwidth, but variable center frequency and gain).
Pan (pot)
Abbreviation of “panorama” controls levels sent to left and right out- puts.
Phantom power, +48V
The phantom power supply, available at the channel mic inputs, for condenser microphones and active DI boxes that require power.
Peaking
An equalizer response curve affecting only a band of frequencies (i.e. based on a bandpass response).
PFL (pre-fade listen)
A function that allows the operator to monitor the pre-fade signal in a channel independently of the main mix.
Phase
A term used to describe the relationship of two audio signals. In-phase signals reinforce each other, out-of-phase signals result in cancellation.
Polarity
A term used to describe the orientation of the positive and negative poles of an audio connection. Normally connections are made with positive to positive, negative to negative. If this is reversed, the result will be out-of-phase signals
Post-fader
The point in the signal path after the fader and therefore, affected by fader level.
Pre-fader
The point in the signal path before the master fader position and there- fore, unaffected by the fader level.
Q
A way of stating the bandwidth of a filter or equalizer section. An EQ with a Q of .5 is broad and smooth, while a Q of 10 gives a narrow, pointed response curve. To calculate the value of Q, you must know the center frequency of the EQ section and the frequencies at which the upper and lower skirts fall 3dB below the level of the center frequency. Q equals the center frequency divided by the difference between the upper and lower –3dB frequencies. A peaking EQ centered at 10kHz whose –3dB points are 7.5kHz and 12.5kHz has a Q of 2.
RCA phono jack
An RCA phono jack is an inexpensive connector (female) introduced by RCA and originally used to connect phonographs to radio receivers and phono preamplifiers. The phono jack was (and still is) widely used on consumer stereo equipment and video equipment but is not gener- ally used in the professional and semiprofessional sound world.
Reverberation (reverb)
The sound remaining in a room after the source of sound is stopped. It’s what you hear in a large room immediately after you’ve clapped your hands. Reverberation and echo are terms that can be used inter- changeably, but by professional audio definitions a distinction is usu- ally made: reverberation is considered to be a diffuse, continuously
smooth decay of sound, whereas echo is a distinct, recognizable rep- etition of a note, phrase or sound.
RMS
An acronym for root mean square, a conventional way to measure AC voltage and audio signal voltage. Most AC voltmeters are calibrated to read RMS volts. Other types of measurements include average volts, peak volts and peak-to-peak volts.
Send
A term used to describe a secondary mix and output of the input sig- nals, typically used for foldback monitors, headphone monitors, or effects devices. Often mixers use the term Aux Send for Auxiliary Send.
Shelving
An equalizer response affecting all frequencies above or below the break frequency (i.e. a highpass or lowpass derived response.)
Solo
A solo circuit allows the engineer to listen to individual channels, buses or other circuits singularly or in combination with other soloed signals.
Stereo return
An input specifically designed to receive the output of effects or other external processing devices
Sweep EQ
An equalizer that allows you to “sweep” or continuously vary the fre- quency with a fixed Q.
Talkback
The operator speaking to the artists or to tape via the auxiliary or group outputs.
Tinnitus
The ringing in the ears that is produced with prolonged exposure to high volumes. BE AWARE OF YOUR EXPOSURE OR PERMANENT EAR DAMAGE WILL RESULT!
Transient
A momentary rise in the signal level.
TRS
Acronym for Tip-Ring-Sleeve, a scheme for connecting three conduc- tors through a single plug or jack. This would include 1 ⁄4" and 1 ⁄8" mini phone plugs and jacks. Since the plug or jack can carry two sig- nals and a common ground, TRS connectors
are often referred to as stereo or balanced plugs or jacks. Another common TRS application is for insert jacks, used for insert an exter- nal processor into the signal path. Typically, the tip is send, ring is return, and sleeve is ground.
TS
Acronym for Tip-Sleeve, a scheme for connecting two conductors through a single plug or jack. This would include 1 ⁄4" and 1 ⁄8" mini phone plugs and jacks. Sometimes called mono or unbalanced plugs or jacks. A 1⁄4” TS phone plug or jack is also called a standard phone plug or jack.
Unbalanced
A method of audio connection which uses a single wire and the conductive shielding as the signal return. This method does not pro- vide the noise immunity of a balanced input.
Unity gain
A circuit or system that has its voltage gain adjusted to be equal one or unity. A signal will leave a unity gain circuit at the same level at which it entered.
volume
Electrical or sound level in an audio system.