This is the second part of my beginner's guide to cables series. In this part I'm going to look at the connectors on the end of the cables.
When it comes to connectors, Neutrik are top, and as such I've quoted their model numbers here. A good set of cables using Neutrik connectors and Sommer cable will last a long time and have a very low failure rate.
XLRs hold the PA world together, being found on mics, mixers and everything in-between, especially mic cables. They consist of three pins, surrounded by a shroud and encased in rubber, making them very difficult to break.
XLRs normally carry a balanced
signal, with the positive "hot" signal present on pin 2 and the anti-phase/negative "cold" signal on pin 3. Pin 1, and optionally the shroud, are connected to ground.
They can also be re-purposed as generic connectors for converter cables, as they have enough pins to carry a stereo line signal as well.
Neutrik's XX-series (NC3FXX and NC3MXX) are virtually indestructible in normal (and a fair amount of abnormal) use. The older X-series had a small flaw in that the latch could break on the male connector, making it prone to fall out of whatever it was plugged into during a gig.
1/4 inch Jacks are used extensively on lower end PA equipment, and equipment that doesn't plan to send a signal very far, such as guitars. They are cylindrical with a funny-shaped tip which holds them in place. They can also have a ring, in which case they are sometimes known as "TRS" (tip, ring, sleeve) connectors.
Most jacks carry an unbalanced signal, with the sleeve being connected to ground, and the tip connected to the signal. However, TRS jacks can be used for balanced or stereo signals, and are sometimes used in the place of XLRs. In this case the tip is connected to "hot" and the ring connected to "cold".
Neutrik's X-series (NP2X and NP3X) can take a lot of beating, being "roadie-proof". They are also much slimmer than the older C-series, making them easier to insert. The biggest danger to a jack is sideways bending, although Neutrik's are strong enough for whatever they're plugged into the break before they do, in most cases.
Neutrik also make a locking jack socket and flying socket. These prevent the jack from being pulled out of the socket accidentally. I've heard claims that they're strong enough to pull the pin out of a jack plug, a claim which I intend to test one day with some sort of test rig; Neutrik plug vs. Neutrik socket! Who will win...
3.5mm jacks are familiar to anyone who's ever owned a pair of headphones, miniaturised versions of TRS jacks.
Neutrik make a very nice little mini-jack (NTP3RC) which is much harder to break than a cheap plastic plug.
Everyone who's worked at an open-mic event will, at some point, have had a massive pop or bang as someone plugs in a guitar before you're ready. A silent plug has a built in switch which doesn't activate until fully inserted, preventing pops and bangs, potentially saving your nice speakers.
Neutrik's silentPLUGs (NP2X-AU-SILENT) are a tad pricey, but once you've started using one you won't ever want to go back. My ultimate guitar cable is finished with a silentPlug.
Speakons are used on speakers and amps to carry the high current required to actuate the driver. Lower and speakers sometimes use jacks, but speakons are better in pretty much every way! They are a form of twist-lock connector, which makes them easy to use, but difficult to accidentally disconnect, unlike jacks.
They carry speaker level signals, and come in 2, 4 and 8 pole variants, which have pairs of + and - connections, made with a screw terminal. 4 poles can be used to carry signals for several drivers across the same cable, making cable runs easier.
Neutrik make the only real speakons, with the SPX-series their current flagship line (NL4FX). The two-pole connector (NL2FC) will mate with an NL4 socket, and can be a good way of reducing cost on cables, which often only need to be 2 pole.
Harting make some of the more widely used multipin connectors, specifically the Han D 108 pin, although many other sizes can be found. A multipin connector allows lots of connections to be made at once - in the case of the 108-pin, 36 channels could be plugged in at once, saving 36 XLR/Jacks to be plugged in.
Hartings are generally used for balanced connections at mic- or line-level, because unbalanced signals don't tent to make it through a multicore very well. However, the connectors are rated for 16A, so could be used for speaker returns are power if necessary. However, Harting have just launched a modular line, which can take a much wider range of signals, including ethernet, USB and pneumatics (or liquids), so is much more suited to mixed signals.
Socapex connectors are another multipin, quite popular for touring. Both brands are very pricey, but tend to make their cost back from the time saved during one gig!
The connectors shown here are the most widely used in PA, and a knowledge of these can prove very helpful. For further reading, go to Neutrik's website
, where there's much more information on their whole product range, or get their catalogue which makes good reading for train journeys!