“I thought cables didn’t matter, so I tried running my system without them. Huge difference!”
— Posted on a hi-fi audio forum

Now that we understand what to measure and how (part 1 and part 2), and know that a null test can prove our measurements valid, let’s use that knowledge to bust some common audio myths.

The earliest audio myth I can recall is the benefit of fancy wire for connecting loudspeakers, and it’s still going strong.

Some vendors claim their wire sounds better than normal wire, and, of course, it’s more expensive than normal wire.

In truth, the most important property of speaker wire is resistance, which is directly related to its thickness.

The wire’s resistance must be small to pass the high-current signals a power amplifier delivers, and this is exactly analogous to a large pipe letting more water flow through it than a small pipe.

For short distances—say, up to 5 or 10 feet—16-gauge wire of any type is adequate, though thicker wire is required for longer lengths.

When heavier gauges are needed—either for longer runs or when connecting high-power amplifiers and speakers—Romex wire typically used for AC power wiring is a fine choice for loudspeakers.

The three other wire parameters are inductance, capacitance, and skin effect, and these will be explained in more detail in the section of this book that covers electronics. But these parameters are not important with usual cable lengths at audio frequencies, especially when connecting speakers to a power amplifier.

Low-capacitance wire can be important in some cases, such as between a phonograph cartridge or high-impedance microphone and a preamp. But high-quality, low-capacitance wire is available for pennies per foot.

Unscientific and even impossible claims for wire products are common because wire is a low-tech device that’s simple to manufacture, and the profit margin for manufacturers and retailers is very high. I could devote this entire section to debunking wire claims, but instead I’ll just summarize that any audio (or video) cable that costs more than a few dollars per foot is a poor value.

Bi-wiring is a more recent myth, and it’s a pretend relative to bi-amping, which is legitimate. No single-speaker driver can reproduce the entire range of audible frequencies, so speaker makers use two or three drivers—woofers and tweeters—to handle each range.

Bi-amping splits the audio into low/high- or low/mid/high-frequency ranges, and each range goes to a separate amplifier that in turn powers each speaker driver. This avoids passive crossovers that lose some of their power as heat and usually add distortion. Bi-wiring uses two separate speaker wires, but they’re both connected to the same power amplifier that then feeds a passive crossover!

A related myth is cable elevators—small devices that prevent your speaker wires from touching the floor. Like so many audiophile “tweak” products, the claim that cable elevators improve sound quality by avoiding damaging static electric and mechanical vibration is unfounded. If vibration really affected electricity as it passed through wires, airplanes—with their miles of wire subject to shock and extreme vibration—would fall from the sky daily.

Indeed, it would be trivial for vendors to prove that audio passing through wire is affected by vibration, thus establishing a real need for their products. To my knowledge, no vibration-control product vendor has ever done that.

Even less likely to improve sound than replacement speaker wire is after-market AC power cords and most other power “conditioner” products. The sales claims seem reasonable: Noise and static can get into your gear through the power line and degrade sound quality. In severe cases it’s possible for power-related clicks and buzzes to get into your system, but those are easily noticed. The suggestion that power products subtly increase “clarity and presence” is plain fraud.

Indeed, every competent circuit designer knows how to filter out power line noise, and such protection is routinely added to all professional and consumer audio products. Buying a six-foot replacement power cord ignores the other hundred-odd feet of regular AC wiring between the wall outlet and power pole.