Here's one explanation from a non-authoritative source, although the
publication is highly regarded in the pro-audio industry:
https://www.soundonsound.com/sound-advice/q-how-should-wire-xlr-cables
The discussion in the link above concludes with a reference to the Neutrik
EMC series XLR connector. It uses an integrated capacitor between Pin 1 and
the shell. For anyone not yet bored by the discussion, have a look at the
bottom table, "Pin 1 Problem" in this Neutrik application note where the EMC
capacitors are shown:
https://www.neutrik.com/media/9117/download/typlical-application-emc-xlr.pdf
?v=1
I'm a bit skeptical of the effectiveness across a broad range of EMI/RFI but
it looks like it may be an "AES acceptable" way to join two midpoint XLR
connectors. The top of the application points to my original concern. See
"Interrupt of Circumferential Shield," and "Connector Shell Floating."
Paul, W9AC
-----Original Message-----
From: Amps <amps-bounces@contesting.com> On Behalf Of Paul Christensen
Sent: Sunday, April 23, 2023 6:21 PM
To: amps@contesting.com
Subject: Re: [Amps] World's worst coax connectors
The AES standard for not bonding Pin1 to the shell is a good overall
strategy. The concern if done in a midline XLR-to-XLR splice is that the
uninsulated metallic shell can inadvertently contact another conductor or
another ground point. Apart from that creating a separate noise issue, it's
a potential safety issue too. OTOH, if the bonded-shell XLR mid-splice is
securely tied out of harm's way, no other audio rule is defeated.
I then must ask: if Neutrik, Switchcraft and other high-end XLR
manufacturers have for decades provided a shell solder terminal, then for
what purpose does it serve? Why not eliminate it altogether and save on
the manufacturing cost? These same manufacturers are highly regarded by AES
members, professional audio engineers, and broadcast engineers.
Paul, W9AC
-----Original Message-----
From: Amps <amps-bounces@contesting.com> On Behalf Of donroden@hiwaay.net
Sent: Sunday, April 23, 2023 3:59 PM
To: amps@contesting.com
Subject: Re: [Amps] World's worst coax connectors
All this is interesting. During my time working at colocated AMs and
doing hundreds of remotes on sat trucks, I don't remember having to
connect the shells of an xlr to pin 1 to eliminate external pickup.
George Washington Bridge seemed to work well.
Don W4DNR
On 2023-04-23 1:19 pm, Jim Brown wrote:
> On 4/23/2023 9:43 AM, jim.thom jim.thom@telus.net wrote:
>
>> ALL of my XLR cables I fabricated myself, were 1 pair, twisted, and
>> teflon insulated..and a woven braid, then the outer pvc
>> sheath...(surplus telco cable we tossed at work).
>
> Jim,
>
> AES Standards, like all REAL Standards, are produced by engineers
> working in a very broad cross-section of the industries who will use
> those Standards. Your application is but a pimple on the elephant. The
> company whose advice you quote, while the designer of truly
> excellent-sounding dynamics processing (for its time) for broadcasting
> and broadcast production, also sells products with SCREAMING Pin One
> Problems, one of which was among several I tested in the VHF-UHF-rich
> environment of downtown Chicago. With properly wired test cables, its
> RF susceptibility made it un-useable. This 2003 AES Paper documents
> that work. http://k9yc.com/AESPaperNYPin1-ASGWeb.pdf
>
> This AES Paper documents corresponding work on condenser mics from
> Neumann, AKG, Sennheiser, and Shure. Although not identified by name,
> the worst offender was Neumnann, the best was Sennheiser. When I
> showed this to the AES Standards Working Group on mics, which
> included members from those companies and others, I did identify them.
> The amusing part was that Sennheiser had by then acquired Neumann, but
> their engineering groups were independent operations.
> http://k9yc.com/AESPaperNYPin1-ASGWeb.pdf
>
> The digital revolution has drastically changed audio signal
> distribution for large scale production in the years since AES analog
> Standards were written, but the stated practice was absolutely
> essential when, for example, in medium to large scale music
> performances two 32-64-input mix desks, usually at widely separated
> locations, are producing separate mixes from the same mics -- one for
> the audience, another for performers on stage. And there are direct
> feeds from amplified instruments like keyboards, guitar, and bass,
> that feed their own amps running on stage power. If the production is
> being broadcast or recorded, a third mix in a truck is producing that
> mix. In addition to their physical separation, the truck will have
> it's own power feed. Those separate mix desks within the facility, or
> with a touring company, were often NOT from transformer isolated
> splits. AES Standards are written so that those applications are viable.
>
> 73, Jim K9YC
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