Comparing Audio Cable Quality

Without a degree in electrical engineering, comparing audio cables is nearly impossible in a market so full of misleading technical terms, fancy photos, "jet engine" style connectors, "silver" conductors, "THX" certification, etc. This article is written to put standard analog audio cables in their proper perspective.

There are endless stories about cables that "improve" audio performance using high technology, special designs or exotic materials. Most of the stories sound convincing, but the boring truth is that cables should not alter an audio signal in any way. So the best cable would transmit audio signals between your components with the least amount of change to the signal.

To attain the least amount of change to an audio signal, a cable has basically two jobs:  one is to internally preserve an audio signal as it moves from device A to device B, and the other job is to protect the audio signal from outside interference. So, regardless of the fancy, high-tech terms used to describe audio cables and the exotic materials used in their construction, an audio cable has a rather simple job: To preserve and  protect the audio signal.

With a focus on audio signal preservation and protection an audio cable has three parts to consider when evaluating quality: 1. cable, 2. connectors and 3. terminations (solder joints).

1. The Cable: When it comes to the audio cable itself, two factors are most important in preserving and protecting audio signals: capacitance and shielding. Conductor thickness or gauge is often talked about, but capacitance reveals more about audio signal preservation. Capacitance is more important than thickness because it reveals signal loss. Capacitance is measured in pF (picofarads) and reveals the amount of signal absorption/loss into the insulation around the conductor. The lower the capacitance, the less signal loss. However, as long as a segment of cable is verifiably below 40 picofarads per foot and made by a brand name manufacturer, capacitance should not impact "audible" sound quality over short distances. To protect audio signals from external interference, foil or copper braid shields are usually used to protect audio signals from power cords, fluorescent lights, and household appliances. To ensure a cable is reasonably shielded from end to end, always stick with established brand names like Belden, Canare or Gepco. These large companies manufacture the spools of cable before they are cut down and connectorized by "cable assembly" companies. In addition, these manufacturers provide publicly verifiable test results on every type of cable they produce, so quality is never a concern. So, rather than trusting a cable seller's description of a cable, you are better off trusting the actual manufacurer of the cable regarding performance specifications. This applies to even the biggest names in cables.

2. The Connectors: Connectors are often highly decorated to improve their marketability and profitability, however connector appearance has no relation to performance. Often, companies that focus on appearance overlook performance issues. So, the best performing connectors are often the least decorative. Quality connectors feature precision-machined cylindrical walls for larger contact area, shielded metal barrels and spring boots to protect the cable from kinking. Gold plating has both advantages & disadvantages. Although sound is not improved with gold plating, it does minimize tarnishing. However, because gold is a softer metal it will sometimes wear off more easily than nickel. To give you an idea, the professional audio industry uses mostly nickel-plated, not gold-plated, contacts. "Locking" connectors sound like a great idea but have the potential of ripping your audio components off the shelf when kicked rather than coming unplugged. Another common practice in connectorizing cables is the use of heat shrink tubing. This tubing shrinks tightly to the cable and/or connector and is often used to completely cover a connector. Although some might like its appearance, heat-shrink tubing is often used to hide cheap connectors or prevent cable buyers from inspecting the cable assembler's solder joints inside the connector. Some of the most expensive cables in the market are often terminated with highly decorative connectors or shrink tubing to make them "appear" to justify the extra cost.

3. Termination: Termination of the connectors onto the cable is one of the most important factors in ensuring audio signal integrity. Poor quality soldering can lead to brittle solder joints that crack and produce unwanted noise or short out a cable. In general, poor quality terminations can also result in loose copper strands or excess solder pieces inside the connector, items that would lead to noise or short out the cable entirely. The solder joints where the cable conductors meet the connector should be done following professional soldering guidelines to ensure high conductivity and durability, and there should be ample separation between neighboring solder joints and/or conductors. Professional soldering guidelines also ensure the solder doesn't grow brittle or crack due to stress or temperature changes. Solder that contains silver rather than pure tin & lead is preferred to improve end-to-end signal transmission. Properly crimping a connector's cable clamp around a cable's jacket also ensures better pulling strength and therefore further protects audio signal integrity.

In conclusion, cables that have no verifiable electrical specifications or connectors that can be opened for termination inspection are what we at A2Z Cables refer to as "mystery" cables. The price or brand name of such cables offer no indication of quality. So before you pay a monstrous price for a mystery cable, consider the three-point inspection listed above. At A2Z Cables our professional grade cables feature Belden, Canare or Gepco brand cables that have verifiable specifications. In addition, our connectors are never glued or molded shut so our customers are always free to inspect the quality of our terminations.