Amplify on Audacity

[newuser]

Hi

I use the select tool to select a segment of the audio and then click on the Effects > Amplify to increase the volume but the OK button is deactivated once I increase the volume - why is this so ?

[steve]

If you look at the waveform (the blue squiggle in the middle of the track) you will notice that there is a very high peak at about 22 seconds.

You have set the amplify level to 10dB, but if you do amplify to 10dB, then that high peak will go too high and will distort (clip), therefore the amplify effect becomes disabled. If you are not bothered about it distorting (NOT recommended), then you can select the "allow clipping" check box in the Amplify dialogue.

By default, Audacity will set the Amplify level to the maximum amplification before clipping occurs.

[kozikowski]

Nobody will shoot you if you carefully select that very high peak and apply a different amplify....

Koz

[steve]

Good point Koz.

Zooming in very tight on that one peak, you could "Amplify" it by a negative amount to bring it in line with the rest of the audio, then select the whole track and amplify it.

[straightupwv]

I used to encounter similar problems when I was running an older computer with less memory and a slower proccessor. There are clues all over the screen shot. if you notice, the highlighted area that is to be amplified does not include the peak at 22 seconds. The new peak amplitude is.7, not zero as it should be. There are four other windows open and something that says "100%" in the task bar. The system tray icons are hidden so there's no way to tell how many background proccesses are running. I think the problem is that the computer itself is being over-taxed. Save your work, either by saving the project or exporting the track as a wav, and reboot. Cut down the number of background proccesses if you can and open Audacity by itself. It should now become more stable.

[steve]

The new peak amplitude is.7, not zero as it should be

THAT is the reason why the "OK" button is greyed out.

Full-scale amplitude would measure as 0 dB, and signals less than that are measured as negative values. Any value greater than 0 dB will clip, but "allow clipping" is not enabled (and generally should not be). Since Audacity is unable to amplify by the set amount (10 dB) without causing clipping, the "OK" button is disabled.

You are quite correct about the selected area straightupwv (when I first read this post, only part of the image loaded, making it look like the whole track was selected, also the bottom of the image was missing).

I think the "100%" could be battery charge.

The other points about shutting down non-essential programs and processes is a good idea, (as is defragging and making sure that there is plenty of free disk space on drive C: ), but these are not the reasons for the "OK" button being unavailable.

[kozikowski]

You people seem to be talking in magic terms because the pictures and your text don't match. May I suggest changing the display from percentages such as this...

http://kozco.com/tech/audacity/Audacity ... andard.jpg

...to actual dB, so all the tools match, like this...

http://kozco.com/tech/audacity/AudacityPanelFull.jpg

You don't need to float the meters. I was just showing off, but all the tools are now in dB and they're all measuring the same audio the same way.

Audio doesn't measure so good in percentages. Half volume to the average ear is 12 %. Half volume on the dB range is -18 which is still clearly visible. See, percents turn into peanut butter pretty quick when you're trying to cut an actual show.

Koz

[steve]

Half volume to the average ear is 12 %. Half volume on the dB range is -18 which is still clearly visible.

To my ear, half volume seems to be about 50% , or -6dB (1/4 volume at 25% or -12 dB, 1/8th volume at 12.5% or -18dB)