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Question about analog audio level vs digital audio level

NYfan2

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I'm working as a volunteer at the local radio and TV station and there was a discussion about the correct level of the audio signal on TV programms. In the end there was a discussion/misunderstanding because one person was talking analog audio levels and the other was talking digital audio levels.

I did some research on this and I find it a bit confusing. Analog audio levels are expressed in dBu or dBV and measure in dBVU. In pro-audio the +4dBu is the reference fo a line level and 0dBVU = +4dBu (correct me if I'm wrong). Digital audio signals are expressed in dBFS, so 0dBFS is the max and higher then 0 is not possible. After some research a common rule is 0dBu ~ -18dBFS.

My question is, if I set the digital audio signal to -18dBFS will then after the DAC the analog audio signal be 0dBu ? And what will the analog VU meter display (-4 dBVU?)

Side note: I know that nowadays the level of audio signals are often measured in LUFS (LKFS) but that's not what my question is about.
 

staticV3

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My question is, if I set the digital audio signal to -18dBFS will then after the DAC the analog audio signal be 0dBu ?
Depends on the DAC really.
Most consumer single-ended DACs will output about -10dBu with -18dBFS input. Consumer differential DACs will output -4dBu.
And in the pro world, anything goes afaik.
And what will the analog VU meter display (-4 dBVU?)
Again, depends on the DAC.
 
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NYfan2

NYfan2

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Depends on the DAC really.
Most consumer single-ended DACs will output about -10dBu with -18dBFS input. Consumer differential DACs will output -4dBu.
And in the pro world, anything goes afaik.

Again, depends on the DAC.
Thank you for your answer, I kind of expected it to be like this.
 
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