XLR vs. 1/4

[DanMarg83]

Okay, I'm still confused about this. What would be the difference between XLR and 1/4 inputs for mics? I see so many interfaces out there that mostly have 1/4 inputs on them, but most mics I see use XLR. Would I just need to use an adapter to go from an XLR cable to a 1/4 plug?

I know about the need for condenser mics to have phantom power and all that already.

 

[Farview]

Interfaces with 1/4 inputs are line level devices. Mics put out mic level (much quieter) so you need to plug the mic into a preamp to boost the signal and the output of the preamp plugs into the line level input of the interface.

 

[DanMarg83]

Okay, I figured preamps were in there somewhere. So I can have a number of preamps lined up and then just plug those all into the interface. Gotcha'.

 

[treymonfauntre]

xlr cables can lock and are balanced, thats why you'll see them on output busses on some consoles

 

[Dani Pace]

XLR cables also have a grounded shield, which helps cut down on noise (interference) especially in lengths of over 20 ft.

 

[cpl_crud]

1/4" can also have a ground sheild.

The main difference is that the XLR cables lock into place.
The "Usual" standard is to have mic level in XLR, and line level in 1/4", however that isn't always the case. As mentioned above, the majority of "pro" desks have XLR outputs.

Basically, it's up to the Systems engineer to decide which cables/adaptors etc are used.
You can use adaptors between either connector, however make sure that you are getting one with the right number of conductors- 2 for unbalanced and 3 for balanced connections.

 

[boingoman]

XLRs have more contact surface area, for one.

They make much more positive connections for two. It's a pin in a sleeve instead of a springy piece of metal against a plug.

Some people feel the 1/4" jack doesn't provide good enough contact (along with it's smaller contact area) for reliable use in mic-level connections.

The conductors can't short out for three- phantom power on a 1/4" connector is asking for a short circuit and lots of noises, as the tip and ring touch the sleeve as they are plugged in. In an XLR, each connection is separate.

And in a related four, pin1 gets connected first, and disconnected last. This can help prevent some noise when patching gear that's on.



ps- not all XLR jacks lock. Non-locking female panel jacks are very common.

 

[Farview]

XLRs have more contact surface area, for one.

The surface area for a TRS and an XLR are almost identical.
Everything else you said was correct.

 

[cpl_crud]

Also, pin 1 only gets the connect/disconnect if the cable has been wired properly. But, assuming that the cable has been made properly, then you're absolutley right.

 

[bubbagump]

To be a little more complete... you have to understand a few concepts. Balanced versus unbalanced, high impedance versus low impedance, and line level versus mic level. The confusing part is that you can mix many of these things. You can run balanced line levels over 1/4" TRS connectors. (You see this a lot with monitor sends on snakes in live sound) You can also run UNbalanced line level over 1/4" TS conectors. Then what gets really confusing is you can run mic level low impedance balanced signals from XLR to 1/4" TRS. And then there are cheap cheap mics which run high impedance mic level signals to 1/4" TS. I don't expect you to really understand some of this... but please do some reading to figure out what all this is about as your life will become much easier if you understand the guts of the beast.

Come away knowing this.... 1/4" and XLR do not necessarily tell you want is being crammed through the pipe. They are simply types of connectors. They TEND to get used for certain applications, but there are always exceptions so you can't take the connector forgranted. You'll find this out the hard way the first time you run a 1/4" speaker out into a line level device and burn it up.