Irvrobinson, you might consider reducing your intake of Haterade! I bet that if scientific proof were under your nose, you would probably dismiss it as product marketing. Current bunching causes resistance and that is not efficient. The research has been done and companies like Analysis Plus, Tara Labs, and more have created cables that allow your sound system to perform better sonically. I've read the Analysis Plus web site. Hollow oval cables. Technical-looking prose, complete with formulae and footnotes. Still unconvincing. Bringing up skin effect is the first indicator of something being off-color. Even at 20KHz skin effect is just not a significant calculated or measured factor in cable performance. Bringing up cable design issues that are relevant in conductors that carry gigahertz frequencies, and then just extrapolate them downward to audio frequencies, where those effects in reality are irrelevant, isn't presenting information honestly. For example, look at Figure 3 on their white paper (981) page. Read closely. That chart is in milliohms per 100 feet of cable. So let's assume for a moment that chart is accurate, how many of us are running 100 feet of speaker cable? And they have to go to milliohms to make the differences apparent? (I'll assume the chart is accurate, though I wonder about how they arrived at those 12 gauge cable figures. Whatever.) Then they keep going to a discussion, complete with a chart with numbers in it, showing how speakers don't have a constant impedance across the frequency range. How quaint. Did you notice their choice of speakers in that chart? The Bose 901, JBL TI250... well, they made me chuckle. I wonder how many Bose 901 customers buy expensive cables? Doesn't this make anyone wonder what their point is? Yes, all speakers have impedance curves that vary by frequency, sometimes by a lot. So what? And then my favorite part, bringing up EMI effects on speaker cables. They even throw in some technical-looking square wave figures, without telling you the frequency of the square waves. 100KHz? 1MHz? Who knows? Speaker cables have such a low impedance and carry high enough voltages that EMI isn't a relevant factor; that's why speaker cables aren't shielded like interconnects. Analysis Plus is taking some technical factors relevant for cables carrying signals well beyond the range of audio signals and trying to convince people they are relevant for audio cables. It's not what I would call true snake oil, but it's not being open with their customers either. And I'm not trying to pick on Analysis Plus, you just brought them up. Audioquest has published worse. |
I am in agreement with a lot of Irv's comments about the Analysis Plus papers, shown here and here. However, I would rate the quality, intelligence, and technical persuasiveness of those presentations MUCH higher than that of the vast majority of cable-related marketing literature I have seen, which in many other cases drives my BS meter to full scale or beyond. One major reason for that, among several, is that the factors they discuss are generally presented in a QUANTITATIVE manner, as opposed to just describing an effect and saying that they have found it to make a significant difference. (Irv, with respect to your question about the frequency of the square waves shown in Figures 5 and 6 of the first reference, the number "10" shown above the figures is presumably microseconds per division, so they are 20 kHz square waves. The figure at the bottom of page 2 of the second reference, the pdf document, appears to confirm that interpretation). Regarding the resistance figure shown for 100 feet of 12 gauge wire, 200 milliohms (0.2 ohms) is in the right ballpark. It is actually about 0.16 ohms according to this wire gauge table. More generally, I would make the following points about the resistance rise at high frequencies which they depict as resulting from "current bunching" and skin effect. 1)Although they indicate that all of their cables are designed based on similar philosophies, that resistance rise has no relevance to analog interconnect cables, for which cable resistance is utterly insignificant with respect to the load impedance. And in most cases it will also be insignificant in relation to the output impedance of the component driving the cable (to which it adds, since the two impedances are in series). 2)For speaker cables, I suppose it is conceivable that a rise from 0.2 ohms per 100 feet to 0.5 ohms per 100 feet at 20 kHz, which their cable avoids, when extrapolated down to more typical lengths might make a VERY slight difference in the upper treble region in some systems, especially if speaker impedance is low at high frequencies (as in the case of many electrostatics). The impedance of dynamic speakers, on the other hand, generally rises significantly in the upper treble region and beyond, and in those cases I can't see how a rise of 0.3 ohms per 100 feet at 20 kHz would make the slightest difference. 3)It should be kept in mind that resistance, and therefore the significance of a given percent variation of that resistance as a function of frequency, can be reduced by simply going to a heavier wire gauge. 4)It should be kept in mind that the effects resistance might have in a speaker cable or analog interconnect cable, if any, will be directly proportional to the length of the cable. The shorter the cable the lower the resistance, at 20 kHz and other frequencies as well as at DC. All of that said, as I indicated earlier in this post I do give their papers excellent marks compared to those of most or all of their competition, and if I personally were shopping for cables in their price range (which I'm not) I would certainly put them at the top of my list of candidates. Mapman, thanks for the kind comment in one of your recent posts. Regards, -- Al |
No doubt high end audio vendors do love to make mountains out of mole hills sometimes. I remember the days when we just sold customers buying good systems 12 gauge speaker wire and called it a day. Then came "Monster" cables. Scary! Then the floodgates opened. Al, you are a knowledgeable and unbiased breath of fresh air and always welcome. I share your opinions regarded wires and such pretty much without exception. |
