HF Noise "Attitude"

Therefore, the most effective test systems will assess these solutions at their ultimate extremes: they magnify the variables under assessment in isolation in order to avoid any and all unintentional influences which may alter the output data. It is, for example, unscientific to formulate theories about audio performance using only one test system, or one test location, or testing at the same hour of each day. Each of these variables, as well as countless others, must be isolated and explored. Finding every possible variant and testing against it is the goal of the LessLoss quality assessment system.

After meticulous computerizations, endless electromagnetic simulations and countless physical trial-and-error sessions, we discovered to our chagrin that those two simple parameters we'd identified were not the end of the story. In order to achieve the non-coloration we desired, as well as the massive through-put of dynamics we needed, what came to light was the decidedly non-scientific and extraordinarily frustrating observation that high frequencies have a somewhat delicate temper.

In anthropomorphic terms: they do not like to be told what to do. But that's ok, mad scientists will do anything to reach the end goal: we were faced with a decidedly touchy subject, so we decided to be exceedingly polite.

Manners work.

At very high frequencies, above those of radio transmission, metal functions not only as a conductor, but simultaneously, as a reflector, inductor, and broadcaster. At these same very high frequencies, signals do not remain solely at the surface of the metal. Instead they bounce off in very strange ways, forming nodes in extraordinarily odd places. In one test example, these nodes were found 2 cm away from all metal parts of the filter, simply standing right there in mid-air, and not necessarily stationary, but moving around seemingly haphazardly, forcing the filter designer to work catch-as-catch-can instead of simply applying his skin effect filtering technique and being done with it.

Such is life with high frequencies -- they can be like adolescents, always three steps ahead of you and always teaching YOU the lessons.

We wanted more filtering and more dynamics, without coloration of the sound. But the high frequencies wanted their freedom and remained quite clear about this. The buggers would simply not be contained.

Must respect them for adhering to their position.

However. We were determined to get the best of them. No snarky little high frequency was gonna mess up our sound quality. No sir.

What we needed was a way to confine and concentrate this erratic high frequency noise into a predictable location so we could eradicate it. The perfect solution would do this without impacting the natural flow of the energy which an audio system requires.

This perfect solution was already in place; exemplified by the DFPC. However, a cross-section of the DFPC has a total conductive area of 18 square millimeters, whereas the LessLoss Firewall would have some 1650 mm2 or more. And whereas the DFPCs cross-section has a 26 mm circumference of skin, the Firewall's early prototype designs had skin circumferences of 780 mm or more. That's nearly a meter, and represents an entirely new electromagnetic field situation within the filter.

The seemingly insurmountable problem was the physical dispersion of all this skin.