LISTSERV mailing list manager LISTSERV 16.0

Help for ARSCLIST Archives


ARSCLIST Archives

ARSCLIST Archives


ARSCLIST@LISTSERV.LOC.GOV


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

ARSCLIST Home

ARSCLIST Home

ARSCLIST  June 2018

ARSCLIST June 2018

Subject:

Re: Processing micro cassette audio using iZotope RX5 & other tools

From:

"Richard L. Hess" <[log in to unmask]>

Reply-To:

Association for Recorded Sound Discussion List <[log in to unmask]>

Date:

Sun, 24 Jun 2018 08:34:09 -0400

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (158 lines)

Hi, Tim and Doug,

In many respects cleaning up music/spoken word for release and forensics 
are two completely different career paths. While iZotope RX is good at 
both, I much prefer projects where I use it for polishing rather than 
trying to dig things out of the noise.

I find it difficult to predict how well I can clean something up until 
I've done it, as each noise-program combination is different.

A couple of thoughts:

--The iZotope de-hum has two flavours of filters (a little check box) 
one seems to have many more artifacts than the other. Sometimes, I'll 
use de-hum to remove the fundamental and a couple of very strong 
harmonics, while using spectral cleaning to work on the upper harmonics 
in another pass.

--I have found that using the spectrum editor (main screen) to remove 
some lines of hum is often more transparent than de-hum. Again, the 
fundamental and a few lower harmonics.

--Spectral noise has a split/link button on some of the faders. When 
split, it allows adjustment of how it works on tonal and noise 
components of the sound. This sometimes helps.

--Ozone is a very useful tool. The parametric EQ is similar to the one 
in RX, but there are also differences and I think I like the one in 
Ozone better, at least for some things.

--The Dynamic Equalizer in Ozone permits a Burwen Dynamic Noise 
Filter-like arrangement that can lower the gain of a frequency band (or 
shelf) when it has little energy present. That doesn't help with digging 
stuff out of the noise, but sometimes the noise is wider band than most 
of the program and that can help with intelligibility.

--Dialog Isolate is an interesting function. I find it often is too 
jarring, but I have provided a dialog isolated track and a cleaned track 
and suggested to the final mixer they mix to suit (it wasn't in the 
budget for me to do that when she could and knew the material better).

--De reverb can sometimes help with intelligibility.

Of course, we see all sorts of different levels of noise affecting 
recordings, so each one needs customized attention.

I trimmed this thread, but left Ellis's and Tim's last messages. 
Unfortunately, Doug's message got posted under a generic "Digest" 
subject, so I'm adding that to this string (immediately below).

Cheers,

Richard


On 2018-06-24 2:21 AM, Douglas Pomeroy wrote:
 > Dan,
 > Broadband is of limited usefulness if you are really concerned about 
transparency.
 > iZotope's RX Denoise allows tailoring of the Curve, after a noise 
sample has been learned,
 > and use of the Curve, with the Threshold and Reduction controls, can 
optimize results, but
 > even after hours of experimentation, you may find little overall 
improvement.
 > And people wonder why this work is so labor intensive!
 > I have always found parametric EQ to be a very powerful tool in noise 
removal work
 > (I still use iZotope's Ozone 5), since some forms of noise cannot be 
well attenauted
 > without a parametric filter.


On 2018-06-24 2:34 AM, Tim Gillett wrote:
> Hi Ellis,
> 
> I feel your point about Denoising and voice intelligibility is 
> important. At
> least intelligibility is some sort of objective standard by which we can
> measure our success. The problem I see with the standard Denoiser tool
> (spectral subtraction) is that it cant lift the partially intelligible 
> voice
> out of the  noise. It only  appears to.
> 
> On Dan's example,  it seems to lift  above
> the noise, the louder parts of the voice - but those louder parts were 
> already intelligible - while leaving the
> quieter less intelligible voice parts still buried in the noise. To 
> increase
> intelligibility the tool would need to lift the quiet parts of the voice
> out of the noise, but it cant. I remember reading an
> article from a CEDAR representative  explaining this to a Forensics
> conference. The tool can only distinguish between soft sounds and loud
> sounds, and assumes that louder sounds are wanted and softer sounds
> unwanted. At some point we have to decide what to leave in (above the line)
> and what to squash (below the line) but in practice
> the voice is mixed in with the noise like eggs are scrambled, and there is
> no clear line. That explains why in a recording where the voice is barely
> intelligible or unintelligible due to broadband background noise, the tool
> is useless.
> 
> Someone once wrote with some irony that the (spectral subtraction) 
> Denoiser tool works best when it's least needed...
> 
> Regards,
> 
> Tim Gillett
> Perth,
> Western Australia
> 
> 
> ----- Original Message ----- From: "Ellis Burman" 
> <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Saturday, June 23, 2018 11:44 AM
> Subject: Re: [ARSCLIST] Processing micro cassette audio using iZotope RX5
> 
> 
> I agree with Tom Gillett.  The adaptive mode of the RX denoiser takes quite
> a bit of time to settle in, and can often over or under process the first
> few words of a sentence before it settles.  Especially since the noise is
> fairly consistent in your case, you should use the manual mode and "learn"
> the noise between sentences.  This will give a more consistent and
> effective result than the adaptive mode.
> 
> The de-hum in RX is terrible.  The notch filters ring like mad.  I love RX,
> but that is one feature of it that I find unusable.  Luckily, we have Cedar
> here, which is crazy expensive, but works like magic, with few artifacts.
> If RX is all you have, I'd be very careful using the de-hum.  I'd use it as
> lightly as possible and listen carefully for the ringing filters.  If you
> have an FIR EQ with a high enough Q, you might be better off using a few
> bands of that, instead of RX de-hum.  Be careful removing tones with the
> spectral editor too.  If you select a long, narrow frequency band and
> attenuate it a lot, it will also ring (and pre-ring!) like mad.
> 
> You should be able to look at the waveform and determine if the clipping
> distortion is playback related.  If the clipping is perfectly horizontal,
> then it happened on playback, so reducing the volume should help.  If the
> distortion is not horizontal and looks more embedded into the waveform,
> then it likely happened during the recording.
> 
> My thoughts on de-noise -  The human brain is very adept at hearing through
> noise, so I've found that removing the noise doesn't help with
> intelligibilty, and often artifacts the audio, making intelligibility even
> worse.  De-noise is often the most damaging and abused restoration process,
> so I'd use it very judiciously, if at all.  It can definitely make a track
> more listenable, but I have yet to hear it make a track more intelligible.
> The human brain is a much more powerful de-noise processor than any 
> plug-in!
> 
> Ellis

-- 
Richard L. Hess                   email: [log in to unmask]
Aurora, Ontario, Canada                             647 479 2800
http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
April 2020
March 2020
February 2020
January 2020
December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003

ATOM RSS1 RSS2



LISTSERV.LOC.GOV

CataList Email List Search Powered by the LISTSERV Email List Manager