Peak Phantom Power
Phase, Phase Shift
Pi (π)
Pickup Pattern
Pink Noise
PL
PLL
(Matrix)
Systems
Pop
Pop Filter
Port
Port Gains
Port ID Numbers and Alphas
The crest value of a voltage, current, or power.
There are three standard voltages: 12, 24, and 48, according to DIN 45 596. Voltage is applied to the circuit in a balanced fashion using a center tapped transformer or two resistors. The size of the resistors depend on the voltage.
Comparing the reference of one waveform to the reference point of another waveform. With periodic waveforms, the phase varies from 0 degrees (waveforms line up), to 180 degrees (waveforms opposite), to 360 degrees (waveforms line up but one is delayed by the time of one waveform).
Symbol for the quantity 3.14159...
Refers to the sensitivity of a microphone to acoustic audio signals originating from different spatial directions.
Equal noise energy per octave. See Conference Intercom Systems.
Phase Lock Loop. A tone decoder utilizing a phase lock loop is used in many of the TW System stations.
A
An undesired effect on a microphone output when a puff of air hits the microphone diaphragm. The effect sounds like a thump or pop. The effect is noticed with the following sounds: “p”, “b”, “t”.
Material placed between a sound source and a microphone that reduces the “pop” effects. It slightly affects microphone performance.
Ports are the individual channels that devices are connected to. Devices include:
RTS™ Keypanels are calibrated to send and receive audio at the standard operating levels of the intercom system. No audio gain adjustment is normally required when connecting these. However, many other types of devices may not operate at the standard intercom system levels. To assure signal level compatibility between the various types of audio devices connected to the intercom system, there are separate analog input and output gain adjustments for each intercom port. It is also possible to adjust the listen gain for any specific intercom port when listening to any other specific intercom port. This is called the
Intercom ports have identification numbers 001, 002 etc. These numbers cannot be changed, but may not be commonly known to intercom system users. Each intercom port also has a default name, called an “alpha”, because this name appears in the alphanumeric displays on keypanels when you assign the ports to keys for talking and listening. The default alpha names are N001, N002 etc. These default alpha names can be changed to ones that are meaningful to keypanel
144 H a n d b o o k o f I n t e r c o m S y s t e m s E n g i n e e r i n g