[linuxworks]

Quote:

Originally Posted by nikongod /img/forum/go_quote.gif Why do all of the manufacturers and "standards" refer to the 4-pin plug as an XLR?

xlr has 3 pins. the shield and that 3rd pin are supposed to be connected; this does not qualify as a 4pin plug. if you treated them as 3 pins and shield, that's still not balanced - so what's the point of all that?

 

[nikongod]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif xlr has 3 pins.

Its a decription of the shell of the connector.
Quote:

the shield and that 3rd pin are supposed to be connected; this does not qualify as a 4pin plug.

I agree, but I was talking about the 4-pin XLR plugs which have a separate shell connection.

BTW, on a 3 pin XLR its the first pin which is generally hooked up to the shield. The third pin is hooked to the "out of phase" leg of the signal. Some Japanese manufacturers have been wiring their 3 pin XLR connectors wrong (by anyone but their own standards) so please note them as a possible exception.
Quote:

if you treated them as 3 pins and shield, that's still not balanced - so what's the point of all that?

2 pins for left channel
2 pins for right channel
shell for shield (if used)
all 4 necessary connections for balanced operation, plus the optional one as applied to a headphone cable.

 

[grawk]

You can insist that xlr is 3 pin only, but that doesn't mean you're right. There are certainly 3, 4, 5, and even 7 pin XLR connectors, and they're all legitimately XLR.

 

[linuxworks]

4 pins and a shield will give you stereo balanced in a single connector. shield is optional and not needed to carry signal, of course.

if you try to map 4 connections to a 3pin_plus_ground plug, you end up running signal over a shield and that's not at all balanced. if you used 4 conductor wire, I *suppose* you could get away with using the shield pin on the xlr jack for a separate non-shield wire.

but at that point, since dual xlrs are not really standard and 4 pin 'xlrs' are also not standard for audio use, you might as well just pick ANY 4 pin jack and plug pair. why try to force xlr to doing things it wasn't meant?

4 pin mic jacks are probably the cheaper and easier way to do this. I'm confused why people think a single 3pin xlr jack is 'good' for 2 channel audio (boggle..)

 

[grawk]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif again, there is no such thing as '4 pin xlr'.

Of course there is. It's used as a standard power connector, and has been adapted for use in audio for quite a few years, starting with AKG with the K1000.
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xlr means 'crossed left and right' (at least one story for the term's origin).

There are lots of stories about what XLR stands for. These days, it means Shield Line Return. But realistically, it's just a name.

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you will CONFUSE pro audio guys if you DARE say '4 pin xlr'. there is just no such thing.

No you won't. They will understand exactly what you're talking about, tho they may not have seen one, or have a use for such a thing in their lives. It's not relevant of course, because home headphone enthusiasts don't need to get pro audio guys to plug in their headphones.

Quote:

xlr is a pro audio thing. the fact that people want to hack their phones to be 4 wire instead of 3 does not mean they have the right to redefine industry standard terms.

The term XLR refers to standards for pin spacing and shell size. The standard includes many varieties. The original was 3 pin, but it's been extended and is definitely a standard connector even with as many as 7 pins.

Quote:

there are 4 pin connectors. but they are not properly called xlr. 'headphonia' or not.

That's just wrong.

Sure, it's not a standard usage to put 2 channels over an XLR connector, and is liable to cause confusion. Beyond that, you're just making stuff up.

 

[nikongod]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif but at that point, since dual xlrs are not really standard and 4 pin 'xlrs' are also not standard for audio use, you might as well just pick ANY 4 pin jack and plug pair. why try to force xlr to doing things it wasn't meant?

but the XLR plugs lend themselves SO nicely to this kind of application.

They all have very high (as far as signal levels are concerned) voltage tolerances, very high current capacity, and they dont short themselves when plugged (unlike a TRS)
Quote:

4 pin mic jacks are probably the cheaper and easier way to do this. I'm confused why people think a single 3pin xlr jack is 'good' for 2 channel audio (boggle..)

I agree, using a single 3-pin for stereo is dumb. it is simply begging to find problems which will quickly be encountered. I think I have seen a single 3-pinXLR used for front and rear of a 4-channel reel-to-reel tape setup, but im pretty sure it was a secondary application using parts that were already being used for the main 2-ch balanced outs.

RE microphone connectors:
older headphones came with DIN connectors as an option, which shares many cool features with an XLR. They could be used with equal success as an XLR in a headphone amp, but it would be something of a unique solution which brings many problems when you try to share your gear with anyone else.

I guess the 4-pin microphone plugs could be used as well, although I dont think they are that much less expensive than a single 4-pin XLR solution and again are somewhat unusual for a headphone app. The screw-down collar always bothers me in an app where quick connections are a benefit. I like the ability to switch headphones with a press of the locking button, and a gentle tug. The screw-down connectors dont hold down worth anything if the screw down collar is not locked.

 

[HiFi1972]

I work in Pro Audio and can tell you that anyone I know (okay, I'm referring to most professionals who've been doing it for a few years anyway) wouldn't be confused by more than 3 pins on an XLR; XLR is a type of connector, doesn't correspond to the # of pins. AES and EBU cables (which carry a digital signal) can also use XLR connectors, as well as other connector types.

 

[HiFi1972]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif go to a pro audio shop (where xlrs are a common item) and ask them if xlrs come in more than 3 pin configs. see the confusion that ensues

No offense to anyone who might work at a Guitar Center or Sam Ash, but those guys don't know much about the more professional side of audio. I don't think I've ever seen a piece of audio gear that uses more than 3-pin XLRs, but anyone who knows more than the basics knows that these things are just connectors, and they can be balanced and unbalanced, depending on how they were wired!