Question on Normalization at DVinfo.net

Jason McGovern · February 16th, 2009, 08:38 PM

Hello... I'm good with cutting/pasting but am newb at more intricate audio adjustments.

I'm working in Adobe Audition and was wondering if normalization is the best way to tackle the problem of clipping. How to normalize so just the clipped sections get nice? And not to effect the other audio information...?

Is there a way to take down auto just clipped areas and to some how round them off so they don't sound so distorted?

Bill Ravens · February 16th, 2009, 08:47 PM

In my experience, normalizing a clipped waveform won't help much, if at all. In some instances, applying a limiter will help. Some tools, will artificially try to restore clipped peaks, like Izotope's RX tool. These have limited success, as well.

Bob Hart · February 16th, 2009, 09:44 PM

I use the ancestor of Audition which is Cool Edit Pro.

I don't know if Audition uses the original dropdown menus or definitions of functions so my comments my be totally wrong.

Normalisation probably won't do much for you. The waveform may already be flattened. You may get something back by selecting "Transform", then "Amplitudue", then "Dynamics Processing" and play around with the compression and expansion presets which you can then adjust and save as a new preset into the library.

Sometimes you might cheat a tiny bit of apparent improvement with "Transform" then "Delay effects" then "Delay" where you can fine tune across a stereo pair which sometimes has the effect of slightly enlivening a a clip that has had all the brightness compressed the hell out of it.

Jason McGovern · February 16th, 2009, 09:50 PM

Yes, thanks -- the Dynamics Processor is very interesting. I'm not sure, but from playing around with it - it really does a nice job reducing the dynamic range. The subject I was interviewing just went from loud to soft - it's all over the place!

I'm going to play with the delay effects you mentioned tomorrow.

I'm a video guy and this is the first time I'm attempting to produce a piece for the radio.

John Willett · February 17th, 2009, 07:57 AM

If it's clipped, it's too late and normalising won't do anyhning at all as it's already been "normalised".

All normalising does is to write the highest peak at 0dBFS (or what you set) and bring everything else up in relation to it - as it's clipped, the loudest peak is already at 0dBFS.

Basically, you need to re-write the peaks so that they are rounded rather than clipped.

Battle Vaughan · February 18th, 2009, 11:08 AM

IIRC Audition has a plugin that attempts to restore clipped audio...I use Sound Forge 9, which has a similar tool which works to some extent by attempting to write tops to the clipped peaks and, I think but am not posititve, expands the unclipped peaks downward to try to provide some sembalance of a normal waveform....

Once the peaks are clipped at 0 dBfs the data is gone, because in digital audio 0 is the absolute end of the digital range and there aren't any more digits above that....

Jason McGovern · February 24th, 2009, 05:03 PM

Thanks guys. John - how do you go abou "re-writing the peaks so that they are rounded rather than clipped"?

Battle - what plugin are you referring to?

Battle Vaughan · February 24th, 2009, 09:34 PM

Jason --

Auditon 3: Resoration > Clip Restoration
Sound Forge 9: Tools >Clipped Peak Restoration

Sorry, plug-in is misleading, these are built-in effects in both cases.

/Battle Vaughan

Rick Reineke · February 25th, 2009, 12:12 PM

"Sound Forge 9: Tools >Clipped Peak Restoration, Sorry, plug-in is misleading, these are built-in effects in both cases."

Clarification:
I don't know about Audition but in Sound Forge-9.0, "Clipped Peak Restoration" is part of the "Noise Reduction 2.0 DX plug-in collection", which is bungled w/ SF-9.0 along w/ CD-Architect among other niceties. Battle is correct about it also being listed in the SF-9 tools menu.

Battle Vaughan · February 25th, 2009, 05:15 PM

Thanks, Rick, I wasn't aware it was a separate piece, it just showed up in the tools menu. I'm wondering if there is a vst plugin that Jason could obtain somewhere, if perhaps this effect is available separately, it might solve his problem..../B. Vaughan

February 16th, 2009, 08:38 PM	#1
Jason McGovern Regular Crew Join Date: Mar 2008 Location: Chicago, IL Posts: 35	Question on Normalization Hello... I'm good with cutting/pasting but am newb at more intricate audio adjustments. I'm working in Adobe Audition and was wondering if normalization is the best way to tackle the problem of clipping. How to normalize so just the clipped sections get nice? And not to effect the other audio information...? Is there a way to take down auto just clipped areas and to some how round them off so they don't sound so distorted?

February 16th, 2009, 09:44 PM	#3
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	I use the ancestor of Audition which is Cool Edit Pro. I don't know if Audition uses the original dropdown menus or definitions of functions so my comments my be totally wrong. Normalisation probably won't do much for you. The waveform may already be flattened. You may get something back by selecting "Transform", then "Amplitudue", then "Dynamics Processing" and play around with the compression and expansion presets which you can then adjust and save as a new preset into the library. Sometimes you might cheat a tiny bit of apparent improvement with "Transform" then "Delay effects" then "Delay" where you can fine tune across a stereo pair which sometimes has the effect of slightly enlivening a a clip that has had all the brightness compressed the hell out of it. Last edited by Bob Hart; February 16th, 2009 at 09:46 PM. Reason: can't spell

February 17th, 2009, 07:57 AM	#5
John Willett Major Player Join Date: Oct 2008 Location: Oxfordshire, UK Posts: 976	If it's clipped, it's too late and normalising won't do anyhning at all as it's already been "normalised". All normalising does is to write the highest peak at 0dBFS (or what you set) and bring everything else up in relation to it - as it's clipped, the loudest peak is already at 0dBFS. Basically, you need to re-write the peaks so that they are rounded rather than clipped. __________________ John Willett - Sound-Link ProAudio and Circle Sound Services President: Fédération Internationale des Chasseurs de Sons

February 16th, 2009, 08:47 PM	#2
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	In my experience, normalizing a clipped waveform won't help much, if at all. In some instances, applying a limiter will help. Some tools, will artificially try to restore clipped peaks, like Izotope's RX tool. These have limited success, as well.

February 16th, 2009, 09:50 PM	#4
Jason McGovern Regular Crew Join Date: Mar 2008 Location: Chicago, IL Posts: 35	Yes, thanks -- the Dynamics Processor is very interesting. I'm not sure, but from playing around with it - it really does a nice job reducing the dynamic range. The subject I was interviewing just went from loud to soft - it's all over the place! I'm going to play with the delay effects you mentioned tomorrow. I'm a video guy and this is the first time I'm attempting to produce a piece for the radio.

February 18th, 2009, 11:08 AM	#6
Battle Vaughan Trustee Join Date: Nov 2008 Location: Miami, FL USA Posts: 1,505	IIRC Audition has a plugin that attempts to restore clipped audio...I use Sound Forge 9, which has a similar tool which works to some extent by attempting to write tops to the clipped peaks and, I think but am not posititve, expands the unclipped peaks downward to try to provide some sembalance of a normal waveform.... Once the peaks are clipped at 0 dBfs the data is gone, because in digital audio 0 is the absolute end of the digital range and there aren't any more digits above that....

February 24th, 2009, 05:03 PM	#7
Jason McGovern Regular Crew Join Date: Mar 2008 Location: Chicago, IL Posts: 35	Thanks guys. John - how do you go abou "re-writing the peaks so that they are rounded rather than clipped"? Battle - what plugin are you referring to?

February 24th, 2009, 09:34 PM	#8
Battle Vaughan Trustee Join Date: Nov 2008 Location: Miami, FL USA Posts: 1,505	Jason -- Auditon 3: Resoration > Clip Restoration Sound Forge 9: Tools >Clipped Peak Restoration Sorry, plug-in is misleading, these are built-in effects in both cases. /Battle Vaughan

February 25th, 2009, 12:12 PM	#9
Rick Reineke Inner Circle Join Date: Aug 2008 Location: New York Posts: 2,039	"Sound Forge 9: Tools >Clipped Peak Restoration, Sorry, plug-in is misleading, these are built-in effects in both cases." Clarification: I don't know about Audition but in Sound Forge-9.0, "Clipped Peak Restoration" is part of the "Noise Reduction 2.0 DX plug-in collection", which is bungled w/ SF-9.0 along w/ CD-Architect among other niceties. Battle is correct about it also being listed in the SF-9 tools menu.

February 25th, 2009, 05:15 PM	#10
Battle Vaughan Trustee Join Date: Nov 2008 Location: Miami, FL USA Posts: 1,505	Thanks, Rick, I wasn't aware it was a separate piece, it just showed up in the tools menu. I'm wondering if there is a vst plugin that Jason could obtain somewhere, if perhaps this effect is available separately, it might solve his problem..../B. Vaughan