Good, Neutral, Reasonably Priced Cables?

Tommy: Thanks for the kind words. I'm glad that your system and ears responded equally well to the Goertz. Both of those are good signs : )

As far as Goertz flat speaker cables go, it does less wrong than any other speaker cable that i'm aware of. The reduction of skin effect due to using a wide flat conductor, the lack of time smear from providing one straight path via a solid conductor, the benefits of proper impedance matching via their exclusive geometry, the lack of in or out of band phase shifts due to reducing inductance to a minimum, the advantages of low series resistance due to using heavy gauge conductors, the benefits of using low loss dielectric, the relatively consistent impedance / series resistance that the cable has regardless of frequency, etc... all add up to form one very complete and well thought out package. If one were to change ANY part of the design, the results achieved would not be anywhere near as good as they are. In effect, the results are due to having a "balanced package" approach to product design. One can do this when they know the parameters of a system that the product will be working within and the amplifier / speaker interface* is pretty cut and dried. On the other hand, interconnects have far more variables involved in terms of the interface that they'll be used in and that's why i've stressed picking the proper speaker cables first and then experimenting with interconnects. Otherwise, you have no point of reference and you have no idea as to what could be wrong or where to start looking. You have to form some type of a baseline to build your system upon.

In plain English, the amp can not only "load up" better into Goertz flat speaker cable, there is less information that is lost or distorted on the way to the speaker itself. As i've stated before, power transfer ( the ability to "load" the signal effortlessly ) and transient response are always optimized when the impedances match or there is very little impedance mismatch involved. As you can see in the independent testing performed on the Audioholics website, Goertz MI-2's provided somewhere between a 2.5 - 8 ohm nominal impedance with the Zobel's in place. As such, the cable itself is basically the same impedance as the speakers being used.

What this accomplishes is multi-fold. That is, the amp is no longer seeing a multitude of complex impedances ( the cables reactance, the speakers reactance and a combo of the two ) to load into, it basically sees the loudspeaker. That's because the electrical traits of the Goertz flat speaker cables have been optimized to fall WAY beyond the audible range. In effect, the Goertz cable becomes "electrically invisible" within the system. Now you get to hear just how well the system is matched and whether or not the amplifier can control the speaker. Since many systems consist of poorly designed gear and / or amps that aren't capable of properly controlling the speakers in use, many folks blame the Goertz cables as being "junk". The fact of the matter is, the Goertz cables simply revealed that the "junk" is somewhere in the rest of the system.

By minimizing skin effect, maintaining the proper impedance over a very wide bandwidth and minimizing phase shifts that are directly related to inductance, you no longer have time smear and reflections ( ringing ) to deal with. In effect, getting rid of the time smear allows the notes to unfold as they normally would i.e. it is no longer "disjointed". This allows you to hear the actual harmonic structure in a far more natural form, increasing the natural "liquidity" of the notes.

Getting rid of the signal reflections that would normally occur due to impedance mismatches allows the amp to deliver cleaner sound i.e. less ringing, smearing and error correction ( negative feedback ). This too contributes to the cohesive presentation that one encounters with this cable in a well thought out system.

Obviously, there are many other factors involved here which i covered over in the AA thread that you mentioned, so i don't want to repeat it all here. Suffice it to say that i didn't get a lot of rebuttal / negative comments on that thread because it's hard to refute verifiable facts.

Tvad: Most Military / Government gear uses proper filtration in the power supply. This negates much of the need for "fancy" power cords and / or power line conditioning. If you remember, i've always said that the better the power supply is designed, the less difference one will notice when trying various power cords. On top of that, the cleaner that the AC is coming into your system from the mains, the less difference one will notice when trying various power cords. To be blunt here, most "high end" audio gear is WAY under-designed in this respect, hence the market for "fancy" power cords. Having said that, most of these power cords are just as inadequately designed as the gear that audiophiles are connecting them to.

Flex: The first cable that came to mind is neither massive in diameter or heavy in terms of weight. It is simply very rigid with a lack of pliable, self-damping jacket material. This combo makes it an excellent conductor of vibration. This cable in raw form is currently being used as both a power cord and speaker cable by more than a few regulars of this and other audio forums. As such, it can do twice as much damage to the system i.e. the directly coupled mechanical vibrations from the speaker cabinet being pumped back into the amp and the acoustically coupled air-borne vibrations from the speakers being coupled to the gear through the mechanically resonant power cords. One can literally "knock" on this cable at one end and feel / hear the vibrations quite easily at the other end 6 - 8 feet away. Needless to say, i'm not using this cable in any of my systems, even though it has quite a bunch of merit to it in terms of electrical design integrity. This just goes to show that even the best design ideas can be implimented in a less than optimum manner. Sean
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Sean,
You have prompted my curiosity on several occasions with these statements, so let me ask whether you have any real evidence or whether these are your hypotheses.
First, what exactly constitutes a well enough designed power supply that cables don't matter (much)? Can you cite any specific piece of digital gear in either the pro or consumer world that, from your experience, has a well enough designed power supply to make the gear impervious to power cords?

Second, have you got evidence that what you call a self-damping jacket material (do you mean dielectric?) will damp out the mechanical vibration of a rigid conductor? Say, a solid core or heavy flat ribbon. I have real doubts that much damping would occur over the length of a typical conductor when either end is subject to shaking. Even if the jacket does some damping, the vibration will occur over at least part of the cable until it damps out, so it depends whether the primary effect of vibration is to produce microphonics within the cable, or whether it is simply to transfer vibration between components. I'm curious because I've seen very little data -just a lot of handwaving or conjecture by a few manufacturers and/or audiophiles.

sean

are the zobel component values (R&C) cited for the goertz cable a function of its length (10 to 20ft in the tests), or can one use those R&C values for any length of goertz cable?

thanks for the most informative posts. the audioholics read was exceptional.

rhyno

This is unquestionably THE best thread since the censorship wars. I don't know how to read, but I listen carefully...

Since I missed the censorship thread, I don't have a point of comparison, but this thread has definitely been very informative and entertaining regardless.

Anyways, more info for all on ribbon cables, subject du jour that they are-

Magnan website 'white paper' on ribbon cable design-

Magnan info

Basically, some of the points here exactly mirror Sean's comments above re. skin effects-

"The skin effect phenomenon has been found to be the major signal degrading effect in conventional audio cables. These effects include smearing of musical details, smearing together of instrumental images, flattening of the sound stage, and usually a general overbrightness. Almost all conventional audio cables utilize relatively thick stranded or solid wires which inherently cause gross audio band skin effect time smearing."

From there, the points seem to diverge, and the white paper becomes a mixed bag that includes fun 'marketing' metrics such as the rigorously defined 'Audio Figure of Merit' in Figure 1. :-(

All that aside, if you check out the soundstage review at

Soundstage Review

the comments on the coherency of the system sound are pretty similar to those I made upthread.

Also, there is a comment on cable theory references at the Silversmith Audio site (another manufacturer of ribbon cables)- if anyone knows more about these, I'd love to hear about it. If not, we'll have to wait for Jeffrey Smith to update the site.

Silversmith

I'm referring specifically to this quote in the 'cable theory' section-

"In the last couple of years, impressive scientific studies have been conducted which have measured some differences in wire performance, including directionality, lending some credence to the subjectivist's camp. While the debate rages on, it is interesting to note, that the engineering knowledge needed to explain exactly why cables do make a difference, and accurately predict what a particular cable design will "sound" like, has been available for decades. Unfortunately for audiophiles, it was not until as recently as 1985 that someone actually applied that knowledge to the world of audio cabling. To this day, the Essex Echo - Unification Tracks 1-4, by Malcolm Hawksford, remains the single greatest work on the subject of audio cabling."

Sean, once again, thanks for the detailed post. I'm busy trying to break down your comments into digestible chunks for my 'challenged' brain. My first question regards your comments on 'minimizing skin effects'.

I guess I don't understand all of the relevant length scales that come into play, so I'll think about this from first principles- if a 'skin effect' is always confined to an esentially infinitely thin skin (on the order of 10s of nanometers; i.e., a few hundred atoms of thickness), then I have a hard time understanding how cable geometry matters at all.

In this case, if one thinks about a cable with a circular cross section, then basically the circumference/area of the cross section is the 2-d analog of the surface/volume ratio. Cicumference/area is always 2/r (r = radius.)

The geometry of a ribbon cross section isn't much different- so long as a ribbon's width is relatively large in comparison to its thickness, its perimeter/area ratio approximates 2/t, (t is the ribbon thickness). This approximation holds pretty well for both Alpha-Core products (MI-2 is w = 0.75 inch and t = 0.01 inch) and Magnan products (Reference speaker ribbon is w = 1.25 inch and t = 0.00075 inch).

What this means is that if skin effects really are confined to a very thin layer, it is immaterial whether cable cross section is circular or ribbon-like. For any given radius r = thickness t, the surface/volume ratio is the same.

Taking it a step further, in comparing surface/volume ratios of any two conductors (a and b, lets say), the ratio of the surface/volume ratios (SVRa/SVRb) is rb/ra, or, if a is a ribbon and b is a wire, rb/ta. If 'minimizing skin effect' is equivalent to minimizing surface/volume ratio, then basically the thicker conductor wins in this scenario, regardless of cross-sectional geometry. This outcome seems counterintuitive given everything one sees in cable design.

Still with me? Yeah, me neither...

What I think must actually be going on is that the 'skin affected zone' is relatively deep (let's call the depth d) compared to r or t in any given conductor cross-section. In this case, one can break the conductor down into outer 'skin affected (sa)' and inner 'bulk (b)' regions. Deriving geomeric relationships between these regions must yield some difference in the behavior of the ratios of 'skin affected area' to 'bulk area' for the two geometries (circular vs. ribbon.)

I'm too lazy/tired to do the math at this point- if someone could confirm that I'm either going in the right direction, or completely lost in the woods, I'll be more motivated to revisit the problem later. On the other hand, if someone wants to pipe in and keep me from reinventing the wheel in this analysis, that would be great too.

Next up- thinking about phase errors...