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  March 2010

ARSCLIST March 2010

Subject:

Re: Disc EQ in the digital domain

From:

Eric Jacobs <[log in to unmask]>

Reply-To:

[log in to unmask]

Date:

Wed, 10 Mar 2010 21:27:24 -0800

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (77 lines)

On Wednesday, March 10, 2010 7:25 PM, Parker Dinkins wrote:

> As a logical progression, click removal before imposing the 
> RIAA playback curve significantly improved in the click 
> detection process because the RIAA playback curve reduces 
> high frequencies.
>
> With modern tools, transferring flat, removing clicks, and 
> then imposing the RIAA playback curve is not as essential to 
> the click removal process as it once was - but it's certainly 
> the conservative and correct approach for archival work 
> because we don't know what further developments will occur
> with digital technology. And it doesn't hurt in the click 
> removal process.

I'm still wondering if the best results are achieved with bass
EQ and flat treble EQ.  The bass EQ guarantees that there is 
no word length loss in the bass, and retains all the impulse
noise information untouched in the treble for noise reduction.


> Back to the main point: the conclusion of R.S. Robinson in 
> my previously cited 2007 AES Paper 7185 was that in most 
> cases the bass resolution truncation was 1 bit or less, which 
> is negligible in light of the 24 bit resolution capability 
> of modern converters, and in all events is more than compensated 
> for by enhancement in the higher registers, where aural acuity
> is greatest (like those Fletcher and Munson boys described).

It's worth noting again that the R.S. Robinson paper is entirely
based on the analysis of vinyl LP media.  In particular, a great
deal of analysis and characterization of the high frequency 
balance found in LPs is made as part of the assumptions of that 
paper.  Pre-vinyl media has dramatically more high frequency 
noise in the form of crackle, clicks and pops than vinyl.

It may be worth mentioning that I participated in tests of
the Channel D Pure Vinyl software EQ with 1940s shellacs, 
and there was clearly a loss of dynamics with the digital EQ 
when compared with the analog EQ.  Clear in that everyone who
participated in the test could easily identify analog versus
digital EQ.

It was this test that started my quest as to "why" there 
was such a notable difference between analog and digital EQ, 
and is leading me to question if FLAT archival transfers for 
pre-LP media really make sense?  Are we actually losing important 
audio information with FLAT transfers of pre-LP media that 
cannot be recreated with digital tools?  Are bass dynamics 
getting quantized away forever with FLAT transfers of pre-LP 
media?

FLAT transfers for pre-LP media is a "best practice" that 
might be worth re-visiting.  I don't think full analog EQ
is the right answer for preservation either.  There may be
a logical middle ground - bass EQ (to prevent word length
loss in the low frequencies) and FLAT treble EQ (to preserve
transients for noise reduction).

No doubt, high performance analog EQ is very expensive.
Digital EQ can be quite cost effective in comparison - with
some minor compromises for LP media - and I think that's the 
case Channel D are trying to make (that the benefits of 
digital EQ outweigh the detriments).  Digital EQ is certainly
a valid approach.  But I'm not sure we fully understand the
compromises we are making with FLAT transfers and digital 
EQ on pre-LP media.

Eric Jacobs

The Audio Archive, Inc.
tel: 408.221.2128
fax: 408.549.9867
mailto:[log in to unmask]
http://www.TheAudioArchive.com 
Disc and Tape Audio Transfer Services and Preservation Consulting

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

December 2020
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