DV/Broadcast Audio Levels

DV/Broadcast Audio Levels

Here are videos illustrating sound level relationships
between DV, Broadcast VU, and Broadcast Peak. There is no direct
relationship between VU and anything else. This is just
to give you a fuzzy starting place.

Import the videos onto a DV timeline, render, and compare the
meters in the picture and the editor's peak sound meter.

The sound track in each case is tone at DV standard -12 followed
by a music track recorded with peaks around -6 to -4.
The tune gets naturally louder and more interesting near the end.


--The picture is of a Beta SP VU meter measuring
the sound. The Beta machine audio inputs
have been adjusted by pulling and turning the audio knobs
so the incoming tone is at zero VU.
Please note the music is mostly in the middle of the meter
with occasional peaks into the red--proper for a US VU meter.

(Same basic show. Different compressions.)

Beta SP VU Meter [82MB....NTSC PhotoJPEG]
Beta SP VU Meter [54MB....NTSC PhotoJPEG]
Beta SP VU Meter [ 5MB....NTSC H.264, AAC, MacQuickTime7]


--The picture is of a US DigiBeta machine peak
audio meter measuring the sound. The DBeta
machine audio inputs have been adjusted by pulling and
turning the audio knobs so the tone is at -20. The music
peaks around the -14 to -12 range--proper for a
broadcast peak meter in the US.

(Same basic show. Different compressions.)

DigiBeta Peak Meter [85MB....NTSC PhotoJPEG ]
DigiBeta Peak Meter [58MB....[NTSC PhotoJPEG]
DigiBeta Peak Meter [ 5MB....NTSC H.264, AAC, MacQuickTime7]


Notes:

--A Sony PVW-2800 BetaCam machine VU meters are "fake,"
sloppy, and peak slightly higher on music than real VU meters.

--A Sony UVW-1800 BetaCam audio level knobs don't need to be pulled.
They're always on.

--Those digital PAL machines that don't use PPMs are generally
adjusted for -18, not -20.

--I don't have a BBC-PPM audio meter, but I know the arithmetic.
If the recorder is adjusted for the tone at 4, there is one music peak
near the end that will approach 6, and no signal goes to Permitted
Maximum Level of 6-1/4.

--All three (four including the BBC-PPM) produce proper sound levels
appropriate to their machine and class of service without ever
changing the DV timeline.

--As a desperation method, the whole timeline, tone
and all, may be reduced 8dB to get about the same
effect as adjusting the recorder, but that will produce
an odd, non-standard DV timeline, and isn't
guaranteed to work with the analog machines.

You can contact me on the Los Angeles Final Cut Pro User Group.

Kozikowski


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