H - Metering Flashcards
what are meters used for when tracking
to ensure input signals do not overload, and you maintain reasonable headroom
what are meters used for during mixing
provide a rough estimate of the loudness of each track, and offer a visual indication of activity when working with a large number of tracks
what are meters used for during the mastering stage
they are used to check compliance with upstream levels and loudness standards, as well as to optimise the dynamic range for a given medium
what are the two meter sub tobics
meter scale and meter ballistics
what is the meaning of meter scale
what signal level corresponds to what indication on the meters.
what is the meaning of meter ballistics
how does the meter respond to changes in level over time.
what does VU stand for
standard volume indicator, and it was designed to indicate volume and not intended to be a unit.
what is the VU meters scale and integration time
the scale reads from -20 to +3 VU
what is 0VU equivalent to
1.228 Volts RMS (+4dBu)
what is a VU meters integration time
the time it takes a VU meter to reach OVU from the bottom (-20VU) is 300 ms +/- 10 %.
the time taken to drop back down to 0VU is standardised as 300 ms
is a VU meter quick enough to respond to peaks
no,
what is a VU meters overshoot percentage
1 - 1.5 %
when calibrating analogue tape what would represent a nominal level to match the optimum level of the tape
0VU
how would you go about calibrating a mixing console
0VU corresponds to an electrical signal (+4dBu), which is calibrated with a sine wave at a level of 1.228 RMS.
what does PPM stand for
peak programme meter
what are the different variations of the PPM
DIN, BBC (UK), EBU UER, Nordic
what are the specifics of the BBC PPM scale
it has no decibel markings, and is labelled from mark 1 to mark 7.
Each mark represents a 4db change, except from 0 to 1 (6db) and 7 to 8 (2dB).
PPM 4 = 0dBu
Mark 5 = + 4dBu
what are the specifics of the BBC PPM integration time
attack time of 5 ms, according to a time constant of 1.7 ms.
some PPMs have a ‘fast option’ with an integration time of 0.1 ms.
fall back time is 1.5 seconds per 20db.
slow fall back time to avoid eye fatigue.
what are the details of the EBU PPM
it is a variant on the British PPM.
test mark = 0dBu.
calibrated differently but otherwise the same
what are the details of the DIN PPM
the 0dB marking is at the edge of the red area.
0dB on the scale corresponds to + 6 dBu, which is 1.55 volts RMS.
the scale ranges from -50 to +5
the test level is marked by a small dot at -9dB below full modulation (0dB)
what are the details of the nordic PPM
the scale ranges from -36dB to + 9dB
in 6 dB steps (apart from + 6 to + 9)
the edge of the red area lies at +6dB.
0dB is the test marking, and is equivalent to 0,775 volts RMS
how do the nordic and din PPMs compare
full modulation to the edge of the red area in both PPMS scales is attained with a voltage of 1.55 V RMS