Joe: Most SS amplifier designs aren't as wide-bandwidth as most of the Threshold / Forte' designs. On top of that, these designs are also different than many other designs in terms of negative feedback and how it is applied. As such, not all SS amps are created equal and / or will respond in like fashion to a high capacitance cable. Please bare in mind that i'm NOT being critical of these designs / products as i'm a great fan of them. I'm simply pointing out that they have the potential to develop problems if certain areas of operation / system building are not properly dealt with.
As i've mentioned before, my beliefs are that system performance has to do with proper impedance matching. The only way to properly match the interface between the output of an SS amplifier and most common speakers would be to use a high capacitance / low inductance speaker cable.
As to your comments about high capacitance cables being "very flat or very skinny", i would beg to differ. Several high capacitance / low inductance designs make use of a large bundle of wires arranged in some type of a round and / or thickly braided array. On top of that, there are other cables that are quite high in inductance / low in capacitance that are "very flat or very skinny". As such, your generalization as to how to recognize a "high capacitance" speaker cable could be quite misleading.
As a side note, Nelson Pass himself wrote a rather lengthy and detailed article about the amplifier / speaker cable interface after running into various "high capacitance / low inductance" fiasco's with his earlier Threshold designs. In this article, he specifically states that both he and Matt Polk individually arrived at much the same conclusion at the same time. That is, the installation of a Zobel Network at the speaker terminals pretty much solves all of the problems associated with high capacitance / low inductance speaker cables.
In this regards, my findings and statements simply confirm what Nelson published 20+ years ago. While i'd like to say that great minds think alike, it would be far more honest of me to say that much of what i know was derived from "audio greats" ( such as Mr Pass and a few others ) that i highly respect and admire. Most everything that i post here or on any other audio forum has already been said before by others that are FAR more knowledgable / experienced than myself. I simply try to pass on the knowledge / experience that the experts have passed on to us and i've personally accumulated over the years.
Mprime: If the MI-2's are linear in power transfer, primarily due to very low inductance, and maintain a consistent series resistance to beyond 100 KHz, which is better than ANY other cable on the market, how could it be detrimental to the treble response that you are encountering?
With that in mind, isn't it possible that what you are encountering IS NOT that the Goertz is "detrimental" to treble "shimmer & air", but that the other cable IS introducing its' own "sonic artifacts" into the system because it isn't as linear??? If we study the facts, this is not a case of "the piano has been drinking" while the pianist is sober.
What i'm getting at here is the output of the amp is identical to what the Goertz feeds into the speaker at the other end i.e. a mirror image. If you look at figures 5, 6 & 7
here, you'll see EXACTLY the same input / output curves from 100 Hz up to TWO MEGAHERTZ ( this is WAY beyond the audible range ) using the Goertz MI-2's. This is with or without the use of an impedance matching ( Zobel ) Network!!! The Zobel, as used in figures 6 & 7, simply flattens out the response above 2 MHz and helps to stabilize certain amplifier designs. It does not in ANY way alter the linearity of the cable anywhere near the audible range.
Now compare the same tests using "less technologically advanced" speaker cabling. As you can see in Figures 8 & 9
, the signal at the far end of the speaker cable doesn't come anywhere close to what the output of the amp tried to load into it. This is with or without the impedance compensation ( Zobel ) network. While the amp is making it out to well beyond 100 KHz, the signal at the far end of the speaker cables is starting to nose-dive at 20 KHz.
In effect, the higher inductance of the speaker cable introduces high frequency roll-off. This will in turn introduce poorer transient response, increased phase shifts, smearing and distortions within the audible upper treble region. The end result is LESS natural sound and an increase in high frequency Td ( Time delay ). Since we know that this isn't anywhere near being "accurate" ( what goes in = what comes out ), choosing to use a cable that introduces specific distortions and / or sonic colourations would strictly be a matter of personal preference.
As i've said before, don't blame the Goertz for showing you what you've got. While you might not like the sound of your system with the Goertz in it, the Goertz is doing nothing less than revealing the true nature of your system. No band-aids, no side effects, just wide-bandwidth linear power transfer. The end result is an increase in system transparency.
If used properly, this can be an effective tool and part of a system foundation that allows one to pinpoint just what the flaws are and where the deficiencies are originating from. After all, if we purposely distort the signal between the amplifier / speaker interface, how can we ever hope to hear any sonic improvements upstream? Since we can't, wouldn't it be more logical to stick with what we can verify / know works the best possible and then try to "guess" / experiment with other things that are more system / component dependent ( like interconnects ) ??? Sean