Splicing In-Line Audio Cable

Edrick

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So we’re extending about 10 XLR cables at the end of a conduit in a 6x6 junction box and now extending another 15’. What would be the best way to do this?

Is a terminal strip / block acceptable?

or solder XLR ends on? Seems terminal block would work just fine?
 

RonHebbard

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as a word of caution, every connection point is a point of potential failure. Make sure your terminal block is clearly labeled and easily accessible. Building it to work is step 1, step 2 is building it so it can be fixed.
Step 3 is: Ensuring all shields are separated and on their own terminals, neither touching one another nor inadvertently contacting any metallic conduit or J boxes. Inadvertent ground loops are NOT your friend; taking care to not create them Is FAR easier than trying to find them after the fact.
Toodleoo!
Ron Hebbard
 

jkowtko

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If you're worried about connection integrity and you can't just use XLR-terminated cables connected together, would it be price prohibitive to just run a new set of cables the entire length? Bulk cable isn't all that expensive relative to conduit runs (I buy from GLS Audio and they have very reasonable prices).
 

JD

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I would solder and heat-shrink wrap. Done right it is very reliable and minimizes the amount of cable that is unshielded.
 

RonHebbard

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If you're worried about connection integrity and you can't just use XLR-terminated cables connected together, would it be price prohibitive to just run a new set of cables the entire length? Bulk cable isn't all that expensive relative to conduit runs (I buy from GLS Audio and they have very reasonable prices).
I'll see your UNDISTURBED XLR's and raise you this:
When a pair of SUPERB quality XLR's are mated and remain totally undisturbed for years ( Example: A Crown SASS-P stereo microphone with integral factory installed XLR's recessed in its back; mounted on the face of a balcony rail and connected via silvered Neutrik's [I'll grant you they weren't Golds] ).
After having operated FLAWLEESLY for 2.5 (Note the decimal point) years, one channel ceased operating. Nary a fault was found. 2 or 3 rematings / burnishing restored flawless operation.
Toodleoo!
Ron Hebbard
 
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Edrick

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I would solder and heat-shrink wrap. Done right it is very reliable and minimizes the amount of cable that is unshielded.
I was considering soldering, trying to do in-line. A bit tedious but can be done haha

so soldering and shrink wrap would you say will be overall better than a terminal block?

I realize overall the “performance” is going to be the same, either will pass phantom power and signal I’d expect without noise issues for that shield splice
 

JD

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After having operated FLAWLEESLY for 2.5 (Note the decimal point) years, one channel ceased operating. Nary a fault was found. 2 or 3 rematings / burnishing restored flawless operation.
I have seen this a lot. Connectors that carry very small signals and are never unmated / remated are prone to this. There is not enough voltage to overcome the microscopic coating of oxide that forms so they go open-circuit. Spade lugs or soldering is the option I chose whenever there is a a chance the connection will not be moved for years.
 

RonHebbard

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I have seen this a lot. Connectors that carry very small signals and are never unmated / remated are prone to this. There is not enough voltage to overcome the microscopic coating of oxide that forms so they go open-circuit. Spade lugs or soldering is the option I chose whenever there is a a chance the connection will not be moved for years.
I couldn't agree MORE. Crown chose to make their XLR's integral, as would any manufacturer targeting that segment of the market.
Had they been targeting the installation market, they'd have no doubt provided a terminal strip.
Can you envision the ubiquitous Shure 58 with terminal's sans its XLR cupped in a performer's hand (s)?
Toodleoo!
Ron Hebbard
 

jkowtko

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I couldn't agree MORE. Crown chose to make their XLR's integral, as would any manufacturer targeting that segment of the market.
Had they been targeting the installation market, they'd have no doubt provided a terminal strip.
Can you envision the ubiquitous Shure 58 with terminal's sans its XLR cupped in a performer's hand (s)?
Toodleoo!
Ron Hebbard
This would be true then for any permanent equipment installation, no? So I wouldn't expect connections between daisy-chained cables to be any worse off than every connection where a cable is plugged into a piece of equipment sitting in the rack.

For that matter, won't terminal strips will still have the same issue too? I think then that the mostly reliable long-term connection would be soldered ...
 
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RonHebbard

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This would be true then for any permanent equipment installation, no? So I wouldn't expect connections between daisy-chained tables to be any worse off than every cable plugged into a piece of equipment sitting in the rack.

For that matter, won't terminal strips will still have the same issue too? I think then that the mostly reliable long-term connection would be soldered ...
@jkowtko Between us, we're opening a serious can of worms here.
Begin with telco punch down blocks. Add ADC RTS broadcast quality jack fields. Combine with genuine Cinch Jones connectors.
Whisk. Blend. Stir and season to taste.
Now; stand well back and avoid the "worms".
Let's invite @Ancient Engineer and @FMEng to the party.
Toodleoo!
Ron Hebbard
 
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DrewE

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In a somewhat similar situation I've used solder barrier strips, such as used to be commonly employed in building amplifiers and such in the tube era, similar to these (though I used a turret style rather than the loop style lug). They can be a bit fiddly to fit up, but I think maybe a little easier to troubleshoot or reconfigure if required when compared to inline splices. They would not be good if there's any foreseeable way for the wires to move about once installed, for rather self-evident reasons.
 

TimMc

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Crimped fork lugs on properly dressed wires to barrier strips were my favorite way to never have a call back. Back when one could get tinned pad barrier strips these were 60 year connections.

Combine with with genuine Cinch Jones connectors.
Whisk. Blend. Stir and season to taste.
Now; stand well back and avoid the "worms".
Let's invite @Ancient Engineer and @FMEng to the party.
Toodleoo!
Ron Hebbard
Jones- the unfaithful connector. You may think it's mated... Leprecon and a bunch of other Lampie crap used them. So happy to not think of them again. Fourty years ago they were readily available and relatively inexpensive so they got used a lot.

For that matter, won't terminal strips will still have the same issue too? I think then that the mostly reliable long-term connection would be soldered ...
I'm sure craftsmanship has changed over the decades but I've not found bad screw-down fork terminal conductivity failure when servicing old installations. Bad crimps? Oh yes. Corrosion? Yes, but the failure was usually where the wire entered the crimp. Most likely intermittent signals were from long frame patch bay jacks that were never cleaned (normal-through contacts) or had been abused with conventional TRS 1/4" plugs, or both. Lots of punch down and some old wire-wrap to those patch bays (some solder too) and the failures were at the jacks.

XLR connections do corrode in situ. So do the switching contacts on switching jacks and 1/4" TRS plugs/jacks that never move. Almost any mating metals that are not gas-tight.

Soldering to terminal strips (like the tone stack in a Fender Twin) is gas tight. Requires some soldering skill and a box to put the work in.
 
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JD

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I liked the QSC amps for installs as they did provide terminal strips for inputs. They had XLR which was fine, but having that terminal option was great for installs. I can't tell you how many service calls I went on that were just connectors that went open. Most times I would clean and reseat, but if there was a way to bypass, I would. The issue is limited to signal cables.
Unfortunately, the issue also extends to inter-board connectors inside equipment, but I have not seen too many problems with them.
 
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FMEng

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For mic level connections, I never use insulation displacement or telco style blocks. They are fine for line level audio. I prefer Cinch 140 series screw terminal blocks and 3M fork lugs. I always use clear shrink tubing over the drain wire, with a short, black, shrink "turtleneck" over the jacket end.

Soldering would also be a solid way to go, provided you are adept at soldering, and provided the cable isn't some cheap crap whose insulation shrinks and melts when the iron gets within 2 feet. I've seen some awful cable used in contractor installs.
 

Ancient Engineer

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I think a punchdown telco 66 block would be effective in a shielded (Carlon box with metal tape on the inside) box...

But really ADC RTS fields isn't a bad idea, except for the real estate needed.

I specify Switchcraft connectors for everything on site here and we annually open the "fixed" connections and Cramolin them...

But, to the OP: I'd re-run the thing with the correct length cabling if at all possible. If not then I'd probably solder with double shrink and a layer of foil between the shrinks.

I'd also over-tail the extensions in case of the need for a re-do.

Time consuming but effective.
 

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