Let's get this out the way now...Leads and cables are boring. There's no denying that, throughout your DJ career leads and cables are the one thing likely to cause you more stress than any other (whether it be trying to untangle them when setting up your rig or frantically checking them when something randomly stops working).
So...annoying?...yes, boring?...yes, essential?...sadly so. It doesn't matter how bit your sound system is, without the right leads to link it all together you won't hear a thing. You could have the biggest lighting rig in town but, without the right connections you'll have no control over it and it'll quickly become chaotic and messy.
So, I think by now we've safely established that leads and cables are going to play an important part in your disco setup so let's have a look at the ones you are likely to come across:
Jack : Jack connections are one of the most commonly used in audio (and a small number of lighting) systems. There are 2 common sizes of Jack plug 3.5mm or 6.3mm (sometimes known as ¼”). As far as DJ, band and studio applications are concerned you are unlikely to see many 3.5mm jack plugs, these are more commonly used for personal audio applications such as iPod headphones etc.
6.3mm (or ¼”) jack plugs come in both mono and stereo types, these can be easily identified by the black rings you can see around the plug, a single ring will indicate a mono plug and two rings will indicate a stereo plug. Mono jack leads can carry a single audio signal and are used, most commonly, for connecting amplifiers to passive speakers. Stereo leads are capable of carrying two signals simultaneously which, most commonly, equates to the left and right audio signals to/from a mixer.
XLR : XLR connections are rarely seen outside of professional audio applications but are the No.1 choice for producers and music professionals as they offer the best quality ‘balanced’ audio signal. Unlike jack plugs, XLR leads come in both ‘male’ and ‘female’ form (male connectors being the ones with pins and female ones being the ones with the holes).
XLR connections are used for nearly all professional microphones, most studio and live PA mixers, a lot of top-end DJ mixers and also for connecting active or ‘powered’ speakers. Unlike Jack plugs which carry both line-level and amplified signals, XLR cables are only ever used for carrying line-level signals.
RCA : RCA connections are the ‘red and white’ plugs. Each lead carries a single audio channel and the red and white plugs are usually used as left and right channels for connecting audio devices. RCA leads are most commonly used in ‘traditional’ DJ setups for connecting vinyl or CD decks to your mixer. You will also find RCA connections for linking mixers to amplifiers, DJ controllers to speakers and on a host of active monitors and (usually lower-priced) powered speakers.
RCA cables are nearly always seen in pairs but can come in threes with an additional yellow plug. This yellow plug is used in video applications and is more common in home installations than professional audio. You may also see a par of RCA leads with a third ‘spade’ connection, this additional connection is used for earthing turntables to prevent audible hum.
Bare-Wire : Bare wire connections are exactly as they sound, there is no plug fitted to the end of the cable and, instead, the bare ‘core’ wire is exposed. Bare wires connect to binding-post or binding-terminal connections which are most commonly found on HI-FI and budget PA speakers. It is rare to find bare-wire connections in professional audio setups.
Speakon : While the word “Speakon” is actually a brand name and a trademark of Neutrik, it is often used as a general term for the blue and black ‘push-and-twist’ plugs. These are usually found on high-powered PA systems for connecting amplifiers to speakers. Speakon connectors are only ever used for carrying amplified or ‘powered’ signals. Speakon cables are not to be confused with Powercon cables which are used for carrying mains power to units with a high power-draw.
DMX : DMX cables are used in lighting applications for connecting lighting controllers and desks to lighting fixtures and lighting fixtures to each other. DMX leads are identical to XLR leads but often have an additional ‘clip’ to secure the cable into the light. XLR and DMX leads are interchangeable but are named differently to differentiate between audio and lighting signals.