Grist for the mill, from the website of my brand of cables (Transparent Audio):
Flat cables with parallel members typically have the highest propagation speeds and the widest bandwidth with some of them passing signals freely into the gigahertz region. Coaxial cables are also relatively high propagation speed, wide bandwidth designs. Flat and coaxial cables are the designs of choice for digital and radio frequency transmission. When these extremely wide band cables are used for audio applications, however, they are particularly subject to noise infiltration along the entire length of the cable, much like an antenna.
The standard ways to approach noise infiltration are through shielding and twisted pair technology, both of which limit cable bandwidth to an extent. Good shielding will reduce electrostatic (ES) noise infiltration. A twisted + and - pair will theoretically prevent electromagnetic (EM) noise infiltration by nulling out these noise frequencies. Cables that employ these geometries will still pass signals freely into the 100 megahertz region and beyond, however, which is far more bandwidth than what is required for audio applications.
In reality, however, twisted pair technology only goes part of the way toward canceling out EM noise because the proximity of the twisted + and - pair is never identical over the whole length of the cable regardless of how carefully the cable is manufactured.
To reduce EM noise beyond what can be achieved through twisted pair technology requires a properly designed network fitted to the specific application and the length and type of cable. Transparent interconnects are well shielded and both speaker cables and interconnects have twisted pair technology. Our networks clean up any residual EM noise not addressed by twisted pair technology by reducing the bandwidth of the cable to that which is required for the application. Limiting bandwidth to that which is required for the application is a basic audio engineering principle that is adopted in every other component category -- speakers, amplifiers, CD players, phono cartridges, etc.
Noise infiltration obscures the ability of the cable to transfer extremely low level harmonic and spatial information accurately, and it has a tendency to make the system sound brighter and harsher in the high frequency region than what is recorded on the source material. Increased noise floor directly affects our ability to perceive full dynamic range and all its gradations.
The Role of Inductance and Capacitance in Audio Cables
Inductance and capacitance need to be carefully controlled in cable. Too much or too little of either characteristic will provide undesirable results. Flat cables, coaxial cables, and even twisted pair cables without networks exhibit electrical characteristics that are not in the best interest of music for several reasons. In lengths suitable for most home audio systems, these cables have too much bandwidth for audio applications and are particularly subject to noise infiltration. Another problem is the point at which these cables achieve electrical resonance; i.e., the point at which inductive reactance equals capacitive reactance.
We have tested a wide variety of flat cables, coaxial cables, and twisted pair, nonnetwork designs on high speed gain phase, impedance analyzers in our laboratory. When we fit the analyzer with a typical audio source impedance to drive such cables into a typical audio load impedance, the point at which these cables achieve resonance falls somewhere between 1500-2500 Hz (depending on the specific cable and its length). This means that such a cable becomes more capacitive at frequencies below 1500-2500 Hz, thereby resisting the transfer of frequencies below 1500-2500 Hz. Twisted pair cables typically have a lower resonant point (usually in the 1500-2000 Hz range) than flat or coaxial designs.
It takes a $ 70,000 piece of equipment, the engineering wherewithal to set up the test properly, and 3-4 hours of "crunch" time per cable to get the data necessary to correlate our conclusions about a particular cable's resonant behavior under audio load conditions. During our 14 years as a cable company, we have listened to and tested hundreds of different types of cables. Cables with extremely wide bandwidth create a thinner and brighter sound than cables with less bandwidth. We think this condition is primarily caused by too high a resonance.
A serendipitous effect of limiting the bandwidth of Transparent Cable with a properly designed network is a lowering of the resonant point, or that frequency where the cable becomes more capacitive and starts to resist low frequencies. In our experience, the sonic byproduct of lowering the resonant point is that music fundamentals and lower order harmonics seem to be passed in the correct proportion to each other and their higher order harmonics. The musical balance is correctly weighted around the two octaves surrounding middle C. Customers, recording professionals, and many fellow manufacturers gravitate to Transparent Cables because they are more able to reveal all the fullness, richness, and dynamic quality of the music as it is recorded.
(etc)
There's a lot more...At any rate it wouldn't seem to me that those responsible for the above explanations about their products obviously fall into the category of mere spinmeisters or snake oil salesman. That would require supposing that no one with any actual technical expertise worked out these designs, which seems like a stretch, call me crazy. Whether it's all too subtle to notice is not something I've had opportunity to form an opinion on.
