reference tone...

[havlowjumper]

I apologize if this question was answered somewhere else... I searched for quite a while but could not find the specific answer to my question.

Is dBfs reference tone measured as an RMS value or PPM? For example when delivery spec. says that ref. tone should be 1kHz sine wave at -20dBfs=0VU do we mean that -20dBfs PPM=0VU or do we mean that -20dBfs RMS=0VU? How is the audio calibrated during transfer to digibeta, with tone as -20dBfs RMS or PPM (how do the decks meters work?)

If I am confusing something please help me out.

thanks in advance for any and all help,
Abe

[minister]

Originally Posted by havlowjumper

Is dBfs reference tone measured as an RMS value or PPM?

Neither.

In the States it is Peak.

a 1k tone is a steady state.

[havlowjumper]

[/QUOTE] a 1k tone is a steady state.[QUOTE]

That makes sense...and admittedly this question is making me feel foolish,

But something still confuses me,

Why then does the PT signal generator create an RMS sine wave that is approx 3dB higher in level than a wave with the peak at the same level? My first thought was that this relates to pan laws, but it does the same with a mono signal. Maybe I am mucking everything up...

any help would be greatly appreciated,
thanks,
Abe

[minister]

has nothing to do with pan laws and everything with the difference between peak level and rms level.

btw, "PPM" stands for Peak Programme Meter -- the type most often used in the UK.

you might want to do a search on metering, levels and the like here and the DUC as well as pick up a book on Audio for Post and Basic Audio. do a search here on books.

[havlowjumper]

thanks for the help...
clearly, there is a breakdown in my understanding here,

-Abe

[georgia]

i think there are a couple of items on metering and reference in my thread... You might what to start there.


cheers
geo