Audacity Forum

The default setting for Normalize maximum amplitude in Audacity 2.2.1 is -1 dB. When I leave it at this I get a peak of -1 to +1 on the vertical scale.

However the manual page talks about bringing the peak up to 0 dB. This doesn't seem to tie up. Could it be made a bit clearer?

ps: is the Normalize maximum amplitude value referring to an absolute value? In which case should it be appended with a suffix?

Happy to get clarification - thanks.

jim1001 wrote:The default setting for Normalize maximum amplitude in Audacity 2.2.1 is -1 dB. When I leave it at this I get a peak of -1 to +1 on the vertical scale.

If you look closely, the maximum peaks will be a little less than 1 (about +/- 0.9)

jim1001 wrote:However the manual page talks about bringing the peak up to 0 dB.

Please give a link and the exact quote.

jim1001 wrote: ps: is the Normalize maximum amplitude value referring to an absolute value? In which case should it be appended with a suffix?

As is common practice for signal processing, the full version would be "dBFS" (reference "full scale"). As is the convention in most audio applications, this is frequently abbreviated to "dB".
https://en.wikipedia.org/wiki/Decibel#Audio_electronics
https://en.wikipedia.org/wiki/DBFS

Thanks for reply.

Please give a link and the exact quote.

Here's the quote from this section:

there are three ways to bring the peak up to 0 dB (+1.0 to -1.0 on the vertical scale).

"Normalize the maximum amplitude" to -0.0 dB

Thanks.

jim1001 wrote:there are three ways to bring the peak up to 0 dB (+1.0 to -1.0 on the vertical scale).

"Normalize the maximum amplitude" to -0.0 dB

Yes, that's correct.

"Full scale" is 0 dB, which is the range +1 to -1 on a linear scale.
Before you complain, yes I know that it is confusing to represent amplitude as dB in some places and a 0 to 1 scale in others, but that a quirk of Audacity's history.

To Normalize to 0 dB / full scale / 1.0 linear absolute, you would set the Normalize effect to normalize to 0.0 dB.
Usually it is best to retain a little headroom, which is why the default setting for Normalize is -1 dBFS.

I have a handy conversion chart.
Click the graphic to see the whole thing.

Convert Percent to Audacity by moving the point to the left. 50% is 0.5. That's half-way which works out to 6dB. That's the only one I remember in my head.

Koz

Thanks both for your time & the very informative replies. I understand it now.

All the best,
Jim