[audacity4blind] Re: Normalizing Versus Amplification Versus Gain
- From: "Robbie" <tickleberryfun@xxxxxxxxx>
- To: <audacity4blind@xxxxxxxxxxxxx>
- Date: Mon, 8 Dec 2014 12:55:25 +0100
Hi Robert!
Thanks a lot for these very insightful explanations. There are some
interesting bits of info there. To use a project mix as a volume gauge
before export is a brilliant piece of advice. I also didn't know that
Amplify could be repeated regardless of the dBFS value. With Audacity,
there's always something more under the surface. :D
Just out of interest, why is the sample format important when using gain?
Cheers! Robbie
-----Original Message-----
From: audacity4blind-bounce@xxxxxxxxxxxxx
[mailto:audacity4blind-bounce@xxxxxxxxxxxxx] On Behalf Of Robert Hänggi
Sent: Saturday, December 6, 2014 7:53 PM
To: audacity4blind@xxxxxxxxxxxxx
Subject: [audacity4blind] Re: Normalizing Versus Amplification Versus Gain
2014-12-06 18:44 GMT+01:00, Rich De Steno <ironrock@xxxxxxxxxxx>:
> Robert, thanks for this detailed response. I pretty much understand
> it, except for this last part:
> My question:
> After you mix and render all tracks to a single track, you say to also
> select the mixed track and then "Normalize or amplify all selected
> tracks, including the mixed track, to e.g. -3 dB, and then to delete
> the mixed track. Why include the mixed track in the normalization or
> amplification? It seems redundant to do so , since it duplicates the
> material in the separate tracks and then you are deleting it anyway.
It is important to include the mixed track and to use amplify (not
normalize).
The mixed track is the sum of all other tracks.
The amplify effect proposes a value that reduces the gain to reach 0 dB.
It takes the loudest track to calculate this value.
That's of course the mixed track.
It then subtracts this dB value from all tracks equally which automatically
results in a perfect mix.
Let's say that our tracks have the following values:
Track 1 -6 dB (0.5)
Track 2 -6 dB (0.5)
Track 3 0 dB (1.0)
mixed 6 dB (0.5 + 0.5 + 1.0 = 2.0)
Amplify will now show "-6 dB".
All tracks are therefore amplified by -6 dB, that is their values are
halved.
And this gives 0.25+0.25+0.5 = 1.0 (without the mixed track, as you can
see).
In order to reach an overall level of -3 dB, you can either directly enter
-9 dB instead of -6 dB or amplify a second time with -3 dB (the proposal
will be 0 dB).
If you would omit the mixed track, the loudest track would be taken (0 dB in
our example) and thus 0 dB amplification will be proposed.
If you want to recreate this example, make sure that you have three
identical tracks. The proposed amplification value will be smaller when the
tracks are different (try e.g. white noise).
The reason is that all individual samples are added together, for white
noise, this could result in anything from -2 to 2 but in average
+ 3 dB instead of +6 dB for two full scale wave forms (i.e. 0 dB or -1
to 1).
However, the procedure works for all cases, just the amplification factor
will change.
I know, that's even more confusing than the last reply...
Robert
The audacity4blind web site is at
//www.freelists.org/webpage/audacity4blind
Subscribe and unsubscribe information, message archives, Audacity keyboard
commands, and more...
To unsubscribe from audacity4blind, send an email to
audacity4blind-request@xxxxxxxxxxxxx
with subject line
unsubscribe
The audacity4blind web site is at
//www.freelists.org/webpage/audacity4blind
Subscribe and unsubscribe information, message archives,
Audacity keyboard commands, and more...
To unsubscribe from audacity4blind, send an email to
audacity4blind-request@xxxxxxxxxxxxx
with subject line
unsubscribe
Other related posts:
