XLR inputs on Carvin 4x12's - What are these used for?

[reguv760]

I've had these 2 Carvin cabinets from a trade. Not too sure how old it is either. It's carpeted in grey and has 4 8ohm 12" Carvin British speakers. I noticed the input for the cabinets have mono/stereo operation, 2 ordinary 1/4 inputs and 2 XLR inputs; a function most new Carvin cabinets do not have (from what i've seen so far).
I was wondering, are these inputs mainly for direct to PA situations or can you use a 1/4 input from a Crate Blue Voodoo120 with an XLR output to cabinet? Can anyone explain what XLR's are for?

Reg

[ryan]

My 5150 cab has an XLR connector as well.

I believe Peavey describes this as a LOCKABLE connection, since the XLR cable clicks into place and can't be accidentally disconnected.

Aside from that, there is no sonic difference since the XLR connector is wired internally for an unbalanced signal.