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  February 2013

ARSCLIST February 2013

Subject:

Polarity Convention was Mono but Out-of-Phase

From:

Goran Finnberg <[log in to unmask]>

Reply-To:

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

Date:

Thu, 7 Feb 2013 22:02:34 +0100

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (130 lines)

Ellis Burman:

http://www.jblpro.com/BackOffice/ProductAttachments/JBL_TechNoteN1V12C_v5.pd
f

Introduction:

When Jim Lansing founded JBL in 1946, he
brought with him a number of traditions developed
during his previous years at Lansing
Manufacturing Company and at Altec-Lansing
Corporation. One of these dealt with polarity
conventions different from those eventually
adopted by the burgeoning loudspeaker manufacturing
community. 

The majority of JBL transducers
at that time exhibited inward motion of
the cone when a positive-going signal was
applied to the red input terminal, and this convention
was, in many cases, carried over into
loudspeaker systems as well.

As we can best
determine, the original polarity decision had
been made by Lansing on an arbitrary basis.


As industry standardization began during the
1950s, JBL took note of the fact that the company
already had a large base of users in the
field and that the productive ³lifetime² of JBL's
transducers was indeed a long one. Any substantial
change in product operating standards
for existing models would have caused chaos
in the field.

Technical Notes, Volume 1 Number 12B

www.jblpro.com/pub/technote/tn_v1n12b.pdf


Polarity Conventions of JBL Transducers and Systems

Introduction:

For most of JBL¹s existence, the company has
designed many transducers and systems with a
polarity convention opposite to the rest of the industry.

The typical JBL transducer exhibited a backward
motion of the cone when a positive-going signal was
applied to the red input terminal, and this convention
was normally carried over into systems.

This situation began to change when JBL first intro-
duced systems intended primarily for musical instru-
ment (Ml) applications. Since these systems tradition-
ally used l/4¹ phone plugs for signal input, there was
no easy way for the user to invert the input signal
polarity. However, there was a need for JBL¹s Ml
products to be consistent with the rest of the industry,
since there is considerable mixing and matching of
systems of different manufacturers in the field.

As time has gone on, there have been many pres-
sures, both internal and external, for JBL to convert
over to the Œpositive-tored² standard which is followed
by the rest of the loudspeaker industry. Such a pros-
pect has never been taken lightly, simply because no
company has more functioning transducers in the
professional field than JBL has. A sudden polarity
change of JBL drivers would cause chaos in the field.


Nevertheless.&hasdecidedtQ&mahean
msition & & M)sitfve-tored standard in accor-
dance with the practice recommended by the AES,
EIA, IEC, and other standards organizations. This will
come about over the next few years, with polarity
changes being effected only in new system and
L transducer models. That is to say, no current models
will be changed to the new polarity convention during
their remaining catalog life.

For this transition to be orderly, it is essential that all
users of JBL products have access to a complete
listing of polarity of current products and that all new
and updated specification sheets carry a clear indim
tion of polarity. This version of Technical Notes Volume
1 Number 12 will be the first of many that will spell out
all polarity conventions. It will be reissued at relatively
short intervals so that there will be a single source of
information on all current JBL products. In addition, all
low-frequency transducers which are of positive
polarity will carry a small sticker which indicates this.
big snip

Applications:
JBL has always recommended that absolute
polarity standards be maintained throughout an audio
system, from microphone input to loudspeaker output.
Since most microphone and electronics manufacturers
adhere to the ³pin-2 hot² convention, this ensures that
a positive-going signal at the input of a microphone
will produce a positive-going signal at the non-ground
output of a power amplifier. If JBL negative convention
loudspeakers are used, the required polarity inversion
should be made at ti loudsr>eaker¹s w &rmin&
themselveS, Note carefully: making the polarity
inversion anywhere else in the system is an invita-
tion to confusion.

-- 
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