Popular Post mansr Posted January 6, 2019 Popular Post Share Posted January 6, 2019 Cable differences are real, and they can be measured. Rummaging through my cable box, I selected a few and measured their frequency response up to 125 MHz using white-ish noise. These are the cables I used: RG-58 coax, 0.5 m, 4.8 mm outer diameter, black RG-58 coax, 2 m, 4.8 mm, black No-name cheap-looking single RCA, 5 m, 2.6 mm, black No-name not-quite-as-cheap dual RCA, 10 m, 2.8 mm, black with red/white plugs No-name video (yellow plugs) single RCA, 1 m, 2.8 mm, black Maplin Pro dual RCA, 0.75 m, 5.9 mm, black + black/grey braid Maplin Pro dual RCA, 3 m, 5.9 mm, black + black/grey braid Maplin (non-pro) single RCA, 1.5 m, 3.7 mm, black with black/blue plugs AudioQuest Tower dual RCA, 1 m, 4.7 mm, black with grey stripes iFi branded dual RCA, 0.5 m, 3.7 mm, purple 21 AWG zip cord, 13 m, 2.0 mm, black Below are spectrum analyser screenshots for each of these cables, in random order. Your task is to guess which spectrum goes with which cable, as many or as few as you like. It's also OK to simply point and laugh at the more silly-looking ones. The noise generator spectrum is inherently a little rolled off, so bear that in mind. Have fun! STC, sarvsa, jabbr and 3 others 4 1 1 Link to comment
Arpiben Posted January 6, 2019 Share Posted January 6, 2019 For the fun be complete do you mind sharing instruments used: Noise generator or AFG and Spectrum Analyzer ? Thanks. Link to comment
mansr Posted January 6, 2019 Author Share Posted January 6, 2019 16 minutes ago, Arpiben said: For the fun be complete do you mind sharing instruments used: Noise generator or AFG and Spectrum Analyzer ? Both are part of a Tektronix MDO3024 scope. Arpiben 1 Link to comment
NOMBEDES Posted January 6, 2019 Share Posted January 6, 2019 Yes. Cable differences are real. But remember that no well constructed cable (what ever the price) is "better" than any other cable. The cable that sounds better to your ears in your system is the best cable. In any dispute the intensity of feeling is inversely proportional to the value of the issues at stake ~ Sayre's Law Link to comment
Hugo9000 Posted January 6, 2019 Share Posted January 6, 2019 I don't have the technical background, so I'm just going to try a little logic. The cheaper bunch of cables are most likely the ones with the "boring" and similar response. My reasoning for this is that companies selling inexpensive cables don't have the time (labor) or ability (materials costs and expensive machinery) to make anything unique, thus will be buying the underlying cable from one of the mass-producers such as Belden, Nexans, Southwire, Mogami, etc. who have the experience, expertise, equipment, and economies of scale in their production to do the most advanced construction affordably, such that other companies can re-brand it or doll it up a touch with a sheath and still make a profit without charging a fortune. A strange (not necessarily "bad" in audio frequencies, but outside the norm of the above "cheap" rebrands of mainstream cable/wire components) test result could be from AudioQuest, as they charge enough money for the majority of their cable offerings to subsidize the most bizarre construction. The very worst result seems likely to be from a company whose products are purely the result of a "cable designer," who may have no understanding whatsoever of the best electrical properties and construction techniques to maximize signal and minimize interference for a given application. "Oh, if this works for this tonearm cable to reduce noise, perhaps I should make a giant version of it for a speaker cable or power cord, or simply twist a hundred tonearm cables together and put it into a silk sheath with platinum connectors." Such a "designer" probably won't have test instruments, or won't know how to use them properly, or won't care or believe it's necessary to even ensure basic performance (or consider extremely negative system interactions if their cable capacitance is extremely high, for example). Anyway, whatever that is worth (probably nothing), that's how I see it by trying to use a little common sense and having no expertise in electrical matters/signal theory/whatever sciences are involved. And of course, this doesn't address sound. It's always possible that the worst result from a technical standpoint will be the most pleasing to the most listeners. 请教别人一次是5分钟的傻子,从不请教别人是一辈子的傻子 Link to comment
pkane2001 Posted January 6, 2019 Share Posted January 6, 2019 2 hours ago, mansr said: Cable differences are real, and they can be measured. Rummaging through my cable box, I selected a few and measured their frequency response up to 125 MHz using white-ish noise. These are the cables I used: RG-58 coax, 0.5 m RG-58 coax, 2 m No-name cheap-looking single RCA, 5 m No-name not-quite-as-cheap dual RCA, 10 m No-name video (yellow plugs) single RCA, 1 m Maplin Pro dual RCA, 0.75 m Maplin Pro dual RCA, 3 m Maplin (non-pro) single RCA, 1.5 m AudioQuest Tower dual RCA, 1 m iFi branded purple dual RCA, 0.5 m 21 AWG zip cord, 13 m Below are spectrum analyser screenshots for each of these cables, in random order. Your task is to guess which spectrum goes with which cable, as many or as few as you like. It's also OK to simply point and laugh at the more silly-looking ones. The noise generator spectrum is inherently a little rolled off, so bear that in mind. Have fun! That's cool, now measure some USB cables up to 1GHz -Paul DeltaWave, DISTORT, Earful, PKHarmonic, new: Multitone Analyzer Link to comment
Arpiben Posted January 6, 2019 Share Posted January 6, 2019 1 hour ago, mansr said: Both are part of a Tektronix MDO3024 scope. Add a directional coupler and a reference load for calibration, then sine sweep in the desired frequency range and you will get the Return Loss ( VSWR ) curve. 😉 Link to comment
manisandher Posted January 6, 2019 Share Posted January 6, 2019 I'd say: 6 = RG-58 coax, 0.5 m 3 = RG-58 coax, 2 m 1 = Maplin Pro dual RCA, 0.75 m The rest, who knows? Mani. Main: SOtM sMS-200 -> Okto dac8PRO -> 6x Neurochrome 286 mono amps -> Tune Audio Anima horns + 2x Rotel RB-1590 amps -> 4 subs Home Office: SOtM sMS-200 -> MOTU UltraLite-mk5 -> 6x Neurochrome 286 mono amps -> Impulse H2 speakers Vinyl: Technics SP10 / London (Decca) Reference -> Trafomatic Luna -> RME ADI-2 Pro Link to comment
Popular Post manisandher Posted January 6, 2019 Popular Post Share Posted January 6, 2019 3 hours ago, mansr said: Cable differences are real... Careful, next you'll be claiming bit-identical playback sounds different 😜 Mani. wgscott and motberg 1 1 Main: SOtM sMS-200 -> Okto dac8PRO -> 6x Neurochrome 286 mono amps -> Tune Audio Anima horns + 2x Rotel RB-1590 amps -> 4 subs Home Office: SOtM sMS-200 -> MOTU UltraLite-mk5 -> 6x Neurochrome 286 mono amps -> Impulse H2 speakers Vinyl: Technics SP10 / London (Decca) Reference -> Trafomatic Luna -> RME ADI-2 Pro Link to comment
Arpiben Posted January 6, 2019 Share Posted January 6, 2019 Curves 8, 9 and 11 are typical of reflections. Now who is who and how it has been measured @mansr knows. In terms of digital transmission it is not impossible that all listed cables sound same. Link to comment
Popular Post jabbr Posted January 6, 2019 Popular Post Share Posted January 6, 2019 Could you list the outside jacket diameters and colors for each cable? wgscott and Ralf11 1 1 Custom room treatments for headphone users. Link to comment
tmtomh Posted January 6, 2019 Share Posted January 6, 2019 If I had to guess, I'd guess 9 or 11 is the Audioquest. But I freely admit that's based largely on my bias against Audioquest (although a bias based in large part on the poor measurements of some of their equipment). Link to comment
mansr Posted January 6, 2019 Author Share Posted January 6, 2019 1 hour ago, jabbr said: Could you list the outside jacket diameters and colors for each cable? I've updated the list with that info. jabbr 1 Link to comment
mansr Posted January 6, 2019 Author Share Posted January 6, 2019 1 hour ago, Arpiben said: how it has been measured @mansr knows Each cable was connected directly from the AFG output to the spectrum analyser input on the Tektronix MDO3024. Any settings not shown in the screenshots are instrument defaults. Link to comment
christopher3393 Posted January 6, 2019 Share Posted January 6, 2019 ...bringin' that Technophile Style! Link to comment
Popular Post Ralf11 Posted January 6, 2019 Popular Post Share Posted January 6, 2019 Easy - the most expensive cables have the most effed up plots. BTW, did you guys know that Optical Cables are Directional? Yes!! Mapleshady said so. eternaloptimist and esldude 1 1 Link to comment
mansr Posted January 6, 2019 Author Share Posted January 6, 2019 4 minutes ago, Ralf11 said: BTW, did you guys know that Optical Cables are Directional? That's because impurities in the glass act as tiny one-way mirrors. Ralf11 1 Link to comment
Popular Post esldude Posted January 6, 2019 Popular Post Share Posted January 6, 2019 59 minutes ago, mansr said: That's because impurities in the glass act as tiny one-way mirrors. That's because they are made in the presence of a directional gravity field. I plan on having some made in the zero g of the international space station. They'll have other outstanding sounds qualities. eternaloptimist and Ralf11 1 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
mansr Posted January 6, 2019 Author Share Posted January 6, 2019 4 hours ago, tmtomh said: If I had to guess, I'd guess 9 or 11 is the Audioquest. But I freely admit that's based largely on my bias against Audioquest (although a bias based in large part on the poor measurements of some of their equipment). I like the way you're thinking, whether your guess is right or wrong. tmtomh 1 Link to comment
jabbr Posted January 6, 2019 Share Posted January 6, 2019 My guess is that the cables with thicker and multicolored jackets will have worse performance Ralf11 1 Custom room treatments for headphone users. Link to comment
mansr Posted January 6, 2019 Author Share Posted January 6, 2019 4 minutes ago, jabbr said: My guess is that the cables with thicker and multicolored jackets will have worse performance That would be a fair assumption, but in this instance it isn't entirely accurate. Link to comment
Ralf11 Posted January 6, 2019 Share Posted January 6, 2019 price/foot on the cables will be a strong correlate of poor performance possible skewed kurtotic distribution tho for ultra-cheapos Link to comment
manisandher Posted January 6, 2019 Share Posted January 6, 2019 48 minutes ago, esldude said: I plan on having some made in the zero g of the international space station. 'Microgravity', not 'zero g' - common misconception 😏 Mani. Main: SOtM sMS-200 -> Okto dac8PRO -> 6x Neurochrome 286 mono amps -> Tune Audio Anima horns + 2x Rotel RB-1590 amps -> 4 subs Home Office: SOtM sMS-200 -> MOTU UltraLite-mk5 -> 6x Neurochrome 286 mono amps -> Impulse H2 speakers Vinyl: Technics SP10 / London (Decca) Reference -> Trafomatic Luna -> RME ADI-2 Pro Link to comment
mansr Posted January 6, 2019 Author Share Posted January 6, 2019 2 minutes ago, Ralf11 said: price/foot on the cables will be a strong correlate of poor performance I don't remember the cost of most, and several were "free," the Audioquest included. Link to comment
Arpiben Posted January 7, 2019 Share Posted January 7, 2019 3 hours ago, mansr said: Each cable was connected directly from the AFG output to the spectrum analyser input on the Tektronix MDO3024. Any settings not shown in the screenshots are instrument defaults. Clear that you didn't use any directional coupler, thanks. Direct from AFG Output (BNC F) to RF Input (N F) it is simply not possible without adaptors. On top of RF Input N->BNC adaptor you probably also used banana/BNC and RCA/BNC ones. Anyhow it doesn't change the game and let me try my luck for the fun. 11 = 21 AWG zip cord, 13 m, 2.0 mm, black 9 = Fi branded dual RCA, 0.5 m, 3.7 mm, purple 8 = AudioQuest Tower dual RCA, 1 m 3 & 6 = RG58 coax Link to comment
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