Shielded signal cable with center conductor and braid—eliminates RF interference. Standard for video feeds and balanced mic lines on set.
Coaxial Cable
On set, you need coaxial cables if you don't want to be grasping at straws – and that's constantly the case. The central conductor carries your signal, the copper braiding around it acts like a Faraday cage, keeping high-frequency interference out. This isn't theory, it's necessity. Without this shielding, you'll get hum in your microphone signal, artifacts in your video feed, or simply a pile of garbage on your hard drive.
In practice, you distinguish between audio coax (e.g., RCA cables or XLR balanced, where XLR also functions as a balanced pair) and video coax (BNC connectors, 75 Ohm impedance). This is important – they are not interchangeable. A video coaxial cable has different impedance characteristics than an audio cable. If you want to send an HD-SDI feed to your monitoring system, you need precisely the right 75 Ohm BNC cables, otherwise you'll lose high frequencies and your image will become muddy. For audio cables – even those with balanced design – impedance tolerances play a lesser role than with video, but shielding is crucial.
On set, you'll notice: cables lie next to power cables, through metal rigging frames, over live electrical cabinets. Each of these situations can introduce EMI (electromagnetic interference) into your signal. A good coaxial cable with dense copper braiding and a torsion-resistant construction keeps these interferences at bay. You can recognize quality by its weight – cheap cables skimp on the shielding braid. You can tell when shaking it: it sounds thin. This will be a problem later.
Practical rule: Never buy the cheapest cable. The few euros difference between no-name and professional cables (Canare, Belden, Neutrik) pay off on set when you don't suddenly discover 30 minutes before a critical take that your audio is humming or your video feed is interrupted. Damaged coaxial cables – kinked, crushed – immediately lose their shielding effect. Store them properly, wind them with care.