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cello23
Known Participant
February 17, 2020
Answered

Asymmetrical wave form after ITU Match Loudness - is it a problem?

  • February 17, 2020
  • 1 reply
  • 532 views

Hello, 

Would appreciate a simple layman-speak answer please!

Is an asymmetric wave form like this (see below) a problem? It sounds OK to me. 

It happens when I use Match Loudness ITU. 

This is for ACX Audible audiobook spec. 

I have done this:

  • Normalise to -3dB
  • Generic high pass
  • Light noise reduction (process)
  • Vocal enhancer plugin
  • Match Loudness  
    • ITU -20 <where it goes asymmetric
    • Total RMS -15
    • ITU -20

 

PS I'm new to mastering and have studied everything I can find; this is by far the best, most natural sound I've got so far after much teeth-gnashing, so if the asymmetry isn't a problem, I'm happy!

Many thanks,

Jules

 

PPS the image wouldn't post for html reasons. It's nicely spikey-varied along the top, but the bottom edge is flat/clipped-looking.

 

 

This topic has been closed for replies.
Correct answer SteveG_AudioMasters_

Without seeing it, it's hard to say - but I can tell you that asymmetry is perfectly normal, and has natural causes - almost invariably caused by human breath. If you have a result you're happy with, and ACX don't reject it, then that's fine.

 

The only real side effect of asymmetry is that it can reduce very slightly the potential peak amplitude of your waveform re. 0dB that you could achieve. But since the ACX stipulations effectively stop you getting anywhere near that situation anyway, and at worst this would only be by a couple of dB, it really isn't an issue.

1 reply

SteveG_AudioMasters_
Community Expert
SteveG_AudioMasters_Community ExpertCorrect answer
Community Expert
February 17, 2020

Without seeing it, it's hard to say - but I can tell you that asymmetry is perfectly normal, and has natural causes - almost invariably caused by human breath. If you have a result you're happy with, and ACX don't reject it, then that's fine.

 

The only real side effect of asymmetry is that it can reduce very slightly the potential peak amplitude of your waveform re. 0dB that you could achieve. But since the ACX stipulations effectively stop you getting anywhere near that situation anyway, and at worst this would only be by a couple of dB, it really isn't an issue.

    C
    cello23Author
    Known Participant
    February 17, 2020

    Brilliant - many thanks, Steve! That's a great help and phew all round. 

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