Shielded Cable – Braided vs. Spiral Shielding
Cables today have an infinite number of designs and purposes. Outside of musical equipment, cables of the same build help run video, computers, and telephone and video networks. Cables using more than a single conductor tend to use twisted pair construction. One major area where construction still differs from cable to cable is in its protection; its shielding. Today, we’ll be discussing the differences between braided and spiral shielding. It’s important to note that each type has its own unique advantages and disadvantages so we’ll let you be the judge on deciding which one is the best fit for you.
Twisted Pair Cabling
First, let’s talk about what’s inside of a typical cable. Twisted Pair cabling is the industry norm used for multi-conductor cables on the market. By standard definition, “twisted pair cabling is a type of cabling in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic capability.” But what does it mean?
In short, a twisted pair can be used as a balanced line – which greatly reduces the amount of noise transmitted through the cable. What the “twisting” provides – in theory – is that the currents in each of the cables are near equal. The twisting simply ensures that each is equal distance from the interrupting source – which would in turn, affect them equally. On the other hand, twisted pair cable’s resistance to interference depends on the twisting scheme to remain in place, and so its efficiency can vary.
Now let’s look at shielding, the first line of defense against external interference in a traveling signal.
This is a spiralling shield of strands of copper running parallel that is made fairly inexpensive. Since the ends of the cable do not need to be untangled, its build can be done pretty quickly.
Because the strands are in a spiral – it is easier to extend. The stretching, theoretically, makes the strands less likely to break when pulled. When the cable is bent or twisted, the spiral strands can gap apart – allowing exposed areas – resulting in frequency interference. For example, patch cables are generally bent and twisted the most – so spiral shielding may not be the best fit for such use, whereas for guitar cables, it’d make more sense.
Advantages of Spiral Shielding
- typically cheaper to make
- easy handle and installation
Disadvantages of Spiral Shielding
- easier for frequency to slip through exposed areas
- breakage is much more frequent
Braided shielding is the most “traditional” form of shielding. Braided cables are woven – thus making it much more difficult to assemble. Typically, braided shielding is stiffer and just as flexible.
Advantages of Braided Shielding
- as strong as it is flexible
- can be installed next to products without power loss
- performs best at low frequency
Disadvantages of Braided Shielding
- does not guarantee 100% coverage as its coverage is dependent on how tightly it is woven
- typically, a bit bulkier
If You Wish To Learn More
Part of audio quality is in cancelling or limiting noise that the conductor picks up between sources. In the case of balanced cables, shielding is less important because they typically transmit line-level audio signals that don’t need to be boosted, and part of their design is to carry two identical signals in opposite polarity before reversing one in the end, which cancels the noise. Hosa carries both a variety of cables with braided and spiral shielding.
For more information on cable shielding and signal flow, check out our video on Do Cables Matter?Hosa