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Lamont Sanford
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Creating test tone CD

When creating test tones using software like NCH Tone Generator what variable amplitude should they be set to. I noticed that the sine wave test tones on the Bink's audio test tones are described such as...

11 16 -1dB 30s
12 20 -1dB 30s
13 25 -1dB 30s
14 31.5 -1dB 30s

What is the purpose of setting a variable amplitude for each tone recorded?

Editor
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Re: Creating test tone CD


Quote:
I noticed that the sine wave test tones on the Bink's audio test tones are described such as...

11 16 -1dB 30s
12 20 -1dB 30s
13 25 -1dB 30s
14 31.5 -1dB 30s

What is the purpose of setting a variable amplitude for each tone recorded?

They all appear to be at -1dBFS, so I am not sure what your question concerns?

John Atkinson
Editor, Stereophile

Lamont Sanford
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Re: Creating test tone CD

I don't understand the purpose of creating the test tone at -1dB. My only guess is to compensate for some type of flat setting average for equalizers. Is that what "dBFS" stands for?

Editor
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Re: Creating test tone CD


Quote:
I don't understand the purpose of creating the test tone at -1dB. My only guess is to compensate for some type of flat setting average for equalizers. Is that what "dBFS" stands for?

Yes, dBFS stands for "dB Full Scale" ie, the maximum level that can be encoded lies at a level of 0dBFS. "-1dB" is 1dB lower than that and has probably been set at that to avoid accidental converter overload. Don't worry about it.

John Atkinson
Editor, Stereophile

BGLeduc
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Re: Creating test tone CD


Quote:
What is the purpose of setting a variable amplitude for each tone recorded?

If you knew the correction factors for the meter that you used for your measurements, you could dial in the test tones so that they were pre-compensated.

If memeory serves, Rives Aduio sells a disc that does exactly that, based on the venerable Radio Shack SPL meter. As such, the value you get on the meter reflects the actual SPL; no additional corrections are needed.

Brian

Lamont Sanford
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Re: Creating test tone CD

Well, I never made that connection. Thanks!

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