Imported audio louder than 0 dB?

[rdfox]

Hi, all!

One of the things I use Ableton Live for is to create DJ edits of music that I have purchased. I'm currently using version 11.0.2. Just this evening I purchased a track that may have been recorded using older analog equipment that does not keep steady tempo, a perfect candidate for a DJ edit.

I imported the track (a 44.1Khz/16 bit stereo WAV file) and kept all the volume settings at 0 dB. I used warping in Complex Pro mode to get all sections of the track to remain in sync with note divisions. Ableton's meters were in the red, though, finishing at a maximum peak of 2.1 dB.

How is it possible for peaks to be above 0 dB in a digital file? Also, has anyone else encountered this issue? I thought I'd ask here before taking it up with tech support.

[pottering]

Yes, it is possible for peaks to be above 0 dB in a digital file, if the audio is 32-bit (16-bit and 24-bit will clip at 0 dB).

https://www.sounddevices.com/32-bit-flo ... explained/

Internally the audio in Live is 32-bit audio, which is why you can see peaks above 0 dB.

If you export uncompressed 32-bit files you can see the above 0 dB peaks preserved in the file (in a app that allows zooming out the waveform, or in Live simply by lowering the Clip Gain)

The digital-to-audio converters will always clip at 0 dB though.

[yur2die4]

Complex and Complex Pro do a lot of processing to psychologically preserve the sound of a warped clip. But they can completely mess with amplitude and frequency content. Any of the other warp modes do not cause additional amplitude.

[Tarekith]

Complex and Complex Pro do a lot of processing to psychologically preserve the sound of a warped clip. But they can completely mess with amplitude and frequency content. Any of the other warp modes do not cause additional amplitude.

I know you're aware of this but just to clarify for others, this is true only when the project tempo is the same as the original audio tempo.

[properLofi]

How is it possible for peaks to be above 0 dB in a digital file? Also, has anyone else encountered this issue?

It is known as inter sample or true peak. Basically it comes about through sampling errors where the curve of the waveform would continue to move up between two samples. This generally occurs when a limiter is applied that doesn’t include true peak analysis but is frequent with MP3s that have been normalised to 0db via a streaming/download platforms. It’s one of the reasons it is recommended to normalise/limit to below 0db when rendering mixes and masters.