Belden 8451 Shielded Audio Cable — Per Metre

Belden 8451 Shielded Audio Cable — Per Metre

Belden 8451 is a single-pair shielded audio and instrumentation cable, sold here by the metre for building and repairing analogue signal cables to exact length. Belden specifies one twisted pair of 22 AWG stranded tinned copper conductors with polypropylene insulation, an overall Beldfoil aluminium foil shield with 100 percent coverage and a matching tinned copper drain wire, finished in a PVC jacket with an overall diameter of 3.51 mm. It is a line-level and low-voltage signal cable: the standard choice inside racks, between balanced equipment, and for microphone and instrumentation wiring where interference rejection matters more than raw conductor size.

Key features

• Genuine Belden 8451 construction, specified by the manufacturer
• Single twisted pair of 22 AWG stranded tinned copper conductors
• Beldfoil foil shield with 100 percent coverage and drain wire
• Polypropylene insulation with black and red conductor colour code
• Slim 3.51 mm overall diameter in a PVC jacket
• Sold by the metre for exact-length cable builds

Construction, as Belden publishes it

Each conductor is 22 AWG stranded 7 by 30 tinned copper, which keeps the cable flexible and easy to solder while the tinning resists corrosion at terminations. The pair is twisted, which is the geometry that lets a balanced input reject interference picked up along the run, and the conductors are colour coded black and red for correct polarity at both ends. Around the pair sits the Beldfoil shield, an aluminium foil polyester tape giving complete coverage, together with a 22 AWG stranded tinned copper drain wire that makes shield termination at a connector simple and reliable. Belden lists nominal capacitance of 34 picofarads per foot conductor to conductor and a nominal characteristic impedance of 45 ohms, with a 300 volt RMS rating and an operating temperature range of minus 20 to plus 75 degrees Celsius.

Where 8451 is used

This is the cable for line-level analogue audio links, balanced interconnects inside equipment racks, console and patchbay wiring, low-voltage analogue signals such as 4 to 20 milliamp and 0 to 10 volt instrumentation loops, low-voltage digital control and panel wiring, all applications Belden lists for 8451. Its slim diameter is an advantage in dense looms where a full-size microphone cable would be bulky. It is not a speaker cable: its 22 AWG conductors are sized for signals, not for carrying amplifier power to a loudspeaker, and using it in that role would waste power and risk overheating on long or loud runs.

Termination guidance

Order the metres your route needs, allowing slack for connector entry and service loops. The drain wire gives a convenient solder point for the shield at XLR, TRS or terminal connections; follow the grounding practice of your system, since shield connection at one end or both ends is a system design decision, not a cable property. Keep pair polarity consistent, black and red to the same pins at each end, and inspect every joint for stray strands before powering equipment. The cable is supplied unterminated: connectors and termination work are separate from this per-metre listing.

Sold by the metre

Belden packages 8451 on large reels; this listing sells it by the metre so project builders and installers can buy a short length for one repair or the full quantity for a rack build without purchasing a complete reel. The jacket marking on the supplied cable identifies the exact construction supplied, and installation classifications should be confirmed from that marking where a documented rating is required by the building work.

For balanced line-level links, rack wiring and instrumentation runs that need a documented, shielded twisted pair, Belden 8451 by the metre is the cable installers reach for, cut to exactly the length the job requires.