Bug in Amplify effect (1.3.5 and 1.3.7)

[Thunderbolt1000T]

I use both 1.3.5 and 1.3.7. I've noticed a bug in the Amplify effect. If I amplify without allowing clipping, and leave the maximum DB set to 0, I've noticed that depending on the sounds in the file, there's sometimes still some clipping after amplification. To fix this, I always set the maximum DB to -1 instead of 0, but this doesn't help with high frequency sounds such as birds.

Has anyone else noticed this bug?

[kozikowski]

It's only a bug after thousands of people notice it. Not before.

The earlier 1.3 versions all had more or less serious problems. The current 1.3.12 is remarkably stable and you should try that.

http://audacityteam.org/download/

Koz

[steve]

Is this related to repeating an effect?

The Amplify effect is different to Normalize in that it amplifies by a fixed amount. The "target" level is calculated based on the current maximum peak, but if you re-apply the effect, then unlike the Normalize effect, the amplification amount remains fixed and is not recalculated.

As an example, if you have a track that has a peak level of -6 dB, the Amplify effect will automatically calculate that +6 dB is required to bring the peak level up to 0 dB. However if you repeat the amplification (for example with Ctrl+R, or using it in a Chain), the amplification will remain at +6 dB. It is not recalculated.

If you wish to use an effect repeatedly that brings the peak level up to a target level, then that's what the Normalize effect does.

[waxcylinder]

And BTW 1.3.5 1and 1.3.7 are old news now - the developers will only be interested if you can reproduce this bug in the latest Beta 1.3.12 - or the latest nightly build Alpha 1.3.13.

WC