Pro Audio Cables | Elementary Cable Facts Tips

Elementary Cable Facts & Tips 

Sun, fire and water, a suitable cable may be exposed to all these forces of nature, as long as you take a few essential precautions.


Cables with a high-quality Soft PVC jacket may be indeed exposed to the elements such as rain without risking malfunction. 
We keep getting inquiries about whether audio or video cables with PVC jackets can withstand use underwater, for instance, in combination with underwater cameras. This is possible as long as the cable is allowed enough time to dry out after use. Temporary underwater installations are also possible, depending on water depth and the associated water pressure. Unfortunately, there is no reliable data available regarding underwater use. There are no consistent technical measurements for this kind of cable. A PVC jacket is not suited for permanent underwater installations, nor are cables with FRNC jackets due to their jacket compound's porous structure. Such use requires custom-designed longitudinally or transversely watertight cables. The wires are insulated either with unvulcanised rubber (longitudinally waterproof) or a special tape (transversely watertight).
In some cases, the cables are reinforced with extra metal protection and filled with petroleum jelly for pressure compensation. Reinforced longitudinally watertight wires are used, e.g. in the shipbuilding or road construction industries. For direct burial or permanent underwater installation, transversely waterproof cables are recommended. Nearly all cables with high-quality insulation (preferably with a PE jacket) are laterally watertight. However, when installing them, one should bear in mind that these must lay the wires in the HDPE conduit, which again is sealed at both ends against moisture entry. If the duct is not provided, we recommend the transversely watertight SOMMER CABLE lines of the AQUA MARINEX series. Depending on the model version, they are designed for permanent use in water depths between 20 and 200 m / 60 and 600 ft and protected against water penetration by a protective band. Please bear in mind that there is no official certification for this type of application. 


Of course, no musician will just keep on playing if the place around him is going up in flames. But why are fire-proof cables still so important? Many permanently installed cable connections are linked to alarm devices or loudspeakers (e.g. for announcements) and thus serve to guarantee safety in case of a fire. In a fire, the cables must not release toxic or suffocating gases either (halogen-free materials). In public buildings, the use of flame retardant and halogen-free cables (FRNC) is most often mandatory. These regulations may differ between countries or states. Inquire about the applicable building code and fire safety regulations in your locale. Detailed information about the fire retardant specifications of our cables can be found in this catalogue in the section "ExplanationExplanation of symbols "under "Properties "or on our homepage and after clicking on the buttons of the respective cable in the bulk cable section. 


Cables are not UV-resistant across the board, but coloured wires, in particular, can be susceptible to direct sunlight. Avoiding premature ageing due to sunlight, an additive is added and mixed into the colour granules from which the insulating layer is made. We do this, e.g. with some white cables to prevent them from premature yellowing. Or you can play it safe and go for a black outer jacket. SOMMER CABLE uses high quality black Soft PVC, PMB and PUR outer jackets. These jackets will not get sunburnt even under continuous and direct sunlight exposure. 

Outdoor Cable Installation 

Outside hooey, inside phooey? Very often, users and media planners are not sure which cable is suitable for outdoor installation. Here we need to distinguish if the cable shall be laid permanently (e.g., as a feed line for a monitoring camera) or only temporarily (e.g., as a PA speaker cable at a Christmas market). For temporary applications at outdoor temperatures down to –10° C / 14° F (SOMMER CABLE S-PVC even down to –30° C / –22° F), a cable with a PVC jacket is sufficient in most cases. But the outer coat should be black or have an additive to protect the cable against UV radiation. 

You'll be on the safe side with our transversely watertight cables of the AQUA MARINEX series, where a" water blocking tape "prevents moisture from seeping up along the shield or the conductor. The UV-resistant jacket made of a particular PUR protects the interior even from the most adverse conditions. The use of cables with a standard FRNC outer jacket is not advisable. Such a coat will pick up moisture very quickly and is mostly not microbe- and UV-resistant. Should there be regulations regarding non-flammability, we recommend selecting cables with a jacket made of halogen-free and flame-retardant Soft PUR.

Why are cables getting "older" too? It is a big secret because if a bit of powder or sand is mixed in, you can save on PVC, but... you lose flexibility. If talcum is added, jacket and insulation soak up moisture like a sponge (e.g., stored in the van of a band, a satellite or remote truck, a rehearsal room, basement, etc.) and rereleases it after even warming up slightly. With the moisture, the softener also disappears, and the cable gets porous and brittle. The original protection of the jacket is compromised. The secret lies in the right balance of ingredients is of the jacket mixture formula.  We leave nothing up to chance. Getting the chemistry right requires a lot of experience, after which follows testing and more testing. The result is a cable of exceptional quality. 

Do you have a special request? 

We can create a cable according to your specifications. We specialise in fabricating speciality cables for the audio and video market, mechanical engineering and telecommunications. We can help you with your cable design process or with marketing your cables. We even manufacture small lot sizes according to your specifications, and we can add your brand name, imprint or logo. Depending on the complexity, the delivery time for these unusual solutions is approximately 5 to 8 weeks. We manufacture cables with• Gold-plating, silver-plating or tin-plated stranding • PTFE-insulation, PVC-, PE-, PP- and VPE-insulation • PVC-, PUR-, HM2-, PE-, TPE-, halogen-free and flame retardant jacket material,  according to VDE 0472 

The "perfect" cable... Experience you can buy. We strive to develop the perfect cable for every application. It must precisely suit your requirements yet be affordable. Here we show you a reference cable as an example, so you know what to look for when purchasing cables: