# Dry Lines / Tie Lines



## AlexDonkle (Oct 1, 2012)

Does anyone know the history of "tie lines" vs "dry lines" (permanent lines that only connect one connection point, to another somewhere else in the theater. No splits, DSP, ect... commonly XLR or TRS jacks). 

Everyone I've met seems to use one phrase or the other, and convinced that the other phrase is wrong. The internet was shockingly sparse on the history of those terms. Anyone know?


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## techieman33 (Oct 1, 2012)

I'm not sure where the names came from. I think the only standard in this industry when naming something is that nothing can have only one name.


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## museav (Oct 1, 2012)

In the telecom and intercom industries a 'dry' line is one with just audio and without any associated DC current/voltage as compared to a 'wet' line containing both audio and DC. A connection from point to point with no inherently associated signal is neither dry nor wet, it simply 'ties' the two points and is thus a tie line. At least that is my interpretation.


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## FMEng (Oct 1, 2012)

Yes, Brad is correct. Dry pair is a telephone company term, also known as an alarm pair. Sadly, they are hard to get now from telcos as copper isn't used much between central offices any more. But, that's a broadcaster whine that doesn't have anything to do with theater.


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## DuckJordan (Oct 1, 2012)

In my area they are used interchangeably, neither wrong or right. In fact our entire facility has several 64+ per panel tie lines running throughout the building and terminating on our main stage. (very nice when we need to put an overfill audio feed into our small theater, or our dance studio)


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## chausman (Oct 1, 2012)

I've always heard them as tie lines, although I don't think either is "wrong" in this sense.


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## Call911 (Oct 2, 2012)

We refer to them as tie-lines. Never heard of dry-lines. In my venues they're wires going from one place in the venue directly back to the patch bay. Very useful for adding feeds anywhere. We have both Audio and Video tielines. Very useful for video recordings of events. We can add cameras anywhere in the theater, and have the video mixer placed anywhere backstage. Saves us from running wires all over the floor.


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## bishopthomas (Oct 2, 2012)

I've never heard of "dry" lines. "Tie lines" seems to be the accepted nomenclature around here.


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## dshriver (Oct 2, 2012)

We have both Tie and Dry lines in my space. Both are just copper runs, no splits, no power, nothing but copper runs. The only difference between them is that the dry lines started out life as feeds to the mic splitters. When we did a system redesign those lines were no longer home run to the splitter. So we used the term "dry" lines instead of calling them "tie" lines to simplify our numbering.


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