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  October 2012

ARSCLIST October 2012

Subject:

Analog to digital dBFS standards

From:

Goran Finnberg <[log in to unmask]>

Reply-To:

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

Date:

Tue, 23 Oct 2012 22:18:09 +0200

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (91 lines)

Tom Fine:

> Mark's method harkens back to the days of 1630 mastering,
> where you needed to find and set your peak levels before
> you made your A-D transfer. This was definitely how my
> mother operated with the Mercury CD's;
snip
> There are technically some very brief digital over-zeros on
> some Mercury CDs here and there, but no one has ever returned
> one because it won't play or it sounds lousy. The manufacturing
> plants tolerated them because their own QC people couldn't hear
> anything that would lead to merchandise returns.

Technically there cannot be overs in a digital audio soundfile.

This is because you cannot exceed full level, 0 dB F/S, in a digital system.

You can not have 0.0001 dB above 0 dB F/S because it is not possible to
register anything in the code that describes such a condition.

Thus a standard evolved using the meter used in the Sony 1630 that indeed
was the de facto standard when sending U-Matic master tapes to the
replicating plant for at least 10 to 15 years of CD production.

The Sony 1630 meter was available as a free standing unit, Sony DMU-30,
costing USD $2500 in 1989.

So a legal over that should register as a clipping of the actual digital
signal has been and is still 4 samples in a row at full scale and this
should be registered as overload with a RED led lighting up or equivalent.

The Sony metering system has internal DIP switches which can be set to any
sensitivity of full scale samples in a row to indicate actual clipping,
overload, but the long time agreed standard is 1-3 samples in a row are
considered legal levels while anything above 4 samples in a row, or more, is
considered as illegal.

So four samples in a row at full levels triggers the "OVER" red led
indicating clipping and is considered "Illegal" and as any and all such
U-Matic CD master must have a PQ list and error report printed and delivered
with the U-Matic master to the replicator then any actual over was ALSO
printed and if a digital master did have any overs when verified at the
plant it was rejected and sent back to the originator to be redone since
overs was not allowed at all.

So in my experience most meters today DO NOT adhere to this standard and it
is anybodys guess what they do show.

It can be anything from -0.3 dB, Pro-Tools, to anything inbetween that and
the actual old Sony standard of 4 samples in arow at full scale.

The Sonic Solutions DAW I am using SSP/USP and HD lights up as "RED" or over
at just one sample over which have these meters light almost coninously when
adhereing to the Sony 1630 standard of 4 samples at full sclae for an over
indication.

So may I suggest that any observed overs on almost any CD out there, Mercury
or other, are all legal when observed on the world standard Sony 1630/DMU30
meter.

For any other claim that something is showing red or is over I would
personally have that digital meter be tested to understand what it is really
showing when going red as most meters are simply wrong in my experience.

The Mytek DDD-603 that I am also using is a Sony DMU-30 meter copycat in
that it follows the world standard precisely in every respect and can also
be set to any amount of overs to indicate a valid over but is normally
shipped to indicate a valid over at 4 samples in a row full scale as the old
1630/DMU.30 does it.

http://www.mytekdigital.com/products/ddd603.htm



-- 
Best regards,

Goran Finnberg
The Mastering Room AB
Goteborg
Sweden

E-mail: [log in to unmask]

Learn from the mistakes of others, you can never live long enough to
make them all yourself.    -   John Luther

(\__/)
(='.'=)
(")_(") Smurfen:RIP

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