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Re: You're Blinded By Believing The Science Being Used Reveal Everything!

Hi Tubeguy

Ah yes, Nick, a great guy, I wish his fortunes had been different with the business, he had some cool stuff.
YES, Paul did fix a pair of TADs, in fact, they are going into a pair of cabinets Nick made for me. They are towers, with a pair of Nicks TD-15’s with a Unity horn in between and a pair of 15” passive radiators at the bottom.
I am hoping with nick’s low inductance drivers and the newer approach to the crossover (than in the Unity) that this system will preserve input waveshape over the three ranges like the SH-50 does.

Umm, all of these things are real, the issue is where are they large enough to be problem or have a detectable effect.
For example, skin effect, a curious electromagnetic phenomena but is it a problem at 20KHz. Looking at the math one see’s that if one had a copper bar an inch in diameter, that at 20Khz the magnetic field bunches up the current and it is located within some small distance at / under the surface.
Compared to DC, the resistance has risen problem, right?
Well, maybe not. The resistance of the copper bar is SO small already, that the amount of difference with the speaker as a load, is infinitesimal.
All of these properties become limiting things as the frequency rises, everything becomes more difficult the more current you have to deal with.
I was Principal investigator on a NASA project to develop high frequency electromagnetic levitation for processing non-conductors without contact.
This involved several hundred amps in a 3 phase opposed coil configuration operating at 12 to 14MHz. The idea was that at those frequencies, a non-conductor like glass is slightly conductive and the eddy current the intense magnetic field produces both heats the object and produces an opposing magnetic force allowing levitation.
I developed and built the transformers for this too which was 80% of the hard part.
If curious, go to one of patent web sites and search my name under inventor, look for Stabilized Electromagneictic Levitator.
Anyway, so far as audio, one can use an HP 3562, a network analyzer like I use to measure cables, wires transformers, capacitors etc, at least up to 100KHz and decide on a case by case basis.
I had to make a long cable for a speaker test tower (combined with Time Delay Spectrometry, gives anechoic measurements of the system under test).
I also needed to take precise impedance measurements in addition for the crossover design process. This meant the cable had to be insignificant so far as its contribution to either acoustic or electrical measurement, not easy for a 150 foot run.
The cable I ended up with is 150 feet long but has about 1/5 the resistance of a pair of 10 meter Kimber cables in parallel, with much less series inductance, much less capacitance.
It’s worth mentioning that a 150 foot #12 extension cord has MUCH more series (leakage) inductance, enough to make a difference of a several dB (and lots of phase shift) at 20KHz, also it had much more parallel capacitance. I would advise only using short lengths (like 50 feet or less) of two parallel conductors like extension cords, much shorter again if the two conductors are not close together.
So, yes all of these things are real and genuine, the issue is when are they large enough to make a difference. For speaker cables, skin effect is insignificant, leakage inductance is a show stopper in long cables. Even resistance is shades of grey, once the R of the cable is about 1/20 or less than the Rdc of the load, its effect is insignificant (also why huge damping factors are meaningless).

It is possible to miss something entirely, it is also possible but unlikely that everyone in audio electronics has always missed some feature of the most appropriate measurement.
That is the weakness / power of measurements one must interpret them , very few have a quantitative number as a result.

Understand too, I am not saying tubes are BAD, not at all.
I have a problem with the snake oil that has (I think) harmed the credibility of our hobby over the last 20 years or so. The magic wall plate and $500 knobs are easy to poke fun at yet the same kind of bs seems to taper smoothly into what is market reality.
I have a problem with some of the SET amp people who add components that cause audible problems while insisting it is an improvement.
It seems to me kind of weird that back when all they had were ears, that the elimination of some of the things / approaches were heralded as obvious improvements, now many of those things (like many interstage transformers) have been revived as being desirable.

The “flip side”, my suspicion as to where the “difference” is can be outlined by the following:

What do Class A circuitry, tubes in general, loudspeakers, microphones, air, most natural processes including your ears, NOT have in common with digital processes, Class AB or B, hard cutoff solidstate, most high negative feedback amplifiers and such??

The first category have non-linearities which get larger at some “power” according to signal level. Conversely, this also means that as the signal gets smaller, so do the non linearity’s.

With the second category, these have nonlineaties which usually become large by proportion as the signal level falls. Consider with the CD, the 8 most significant bits describe the top 6dB of dynamic range, the least significant bit (one bit) defines the last 6 dB. The lower the level, the less the resolution is.
Many high fb amplifiers show a falling distortion with falling level, down to some power and then it flattens out or even increases.
Ears don’t / can’t hear distortion until its huge in a transient, it is most audible in a continuous signal. In music, (for me) I hear these differences in the tails of the sound, the trailing edge where the level is smoothing decreasing.

I would be curious to hear your idea for quantifying musicality but would suggest that you use natural sounds as well as music. Limiting it to music would have a bias towards harmonically related material (which natural sounds are not generally harmonic in structure).
In terms of “Realism” the faithful reproducer does a good job with any signal.
While musicality is more nebulous so far as measurement, relative faithfulness or lack of is the difference between the input and output in amplitude and time, much easier to measure.
I feel like I know both sides, the first half of my audio life I spent with little or no measurement ability, depending entirely on my ears and what I could read in magazines.
The second half, is when I have had many inventions but I wouldn’t be crazy about audio if I didn’t enjoy listening.
Best regards,

Tom Danley






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