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Post by fbczar on Oct 15, 2022 12:28:12 GMT -5
OK - Let's cut to the chase: I agree that KeithL is an expert on all things audio and does know far more than I on every audio topic. HOWEVER, I am also in the middle of a cable review for a major cable manufacturer and am in direct contact with the gentleman who designs the cables. The company is one of the largest in the audio field, and offers speaker wires in every price category. The designer says about cable risers: "Cable risers reduce the amount of RF noise that capacitively couples into the speaker cables through all solid flooring materials. Successfully designed and properly used, cable risers will preserve valuable low-level detail for more natural, dynamic, involving performance." Yes, it IS "advertising speak," but there is no ambiguity. He recommends cable risers - KeithL doesn't. Now neither KeithL NOR the cable designer sells cable risers, so neither has any financial motivation to lie or exaggerate. So I now have two experts telling me diametrically opposing things. Which "expert" is to be believed? The easiest solution is to listen for myself and then report what I hear. And in spite of the fact that not even experts agree on this topic, I still have to contend with ignorant yahoos trying to tell me how foolish I look and how I know nothing... Go figure. Glenn Young (aka Boomzilla) Boom, Any discussion of analog noise (RFI, EMI, etc.) is doomed unless all the folks involved in the discussion understand that you are not talking about something like hum or hiss. It is also unlikely any meaningful discussion can take place unless everyone involved has normal or better hearing and are owners of systems that are highly resolving. Low noise streamers, high quality power supplies, optical ethernet cables, USB cables designed to isolate data from power, Power Cables that act as filters, and cable risers are all used to lower analog electrical noise. Obviously, every system is different so each of the devices mentioned can vary in their individual impact. And the cumulative effect of all analog noise reduction is a consideration. No doubt some things work in a noticeable way and others not so much. I can hear the difference in soundstage, detail and blackness of background made by my UltraRendu, Sonic Transporter computer and linear power supplies. I can discern the effect of optical ethernet cables. I have not tried upgraded power cables or cable risers, but given the low cost of DIY cable risers it is certainly worth trying. Perhaps speaker cables do not relate to analog noise reduction, but I can hear a difference between short and long cables and between my Mark Levinson 10AWG cables and all my other cables. I would love to audition some woven cables to see if they make a difference. It would be great if everyone would experiment and listen before rejecting a tweak out of hand, but that is way too much to hope for.
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Post by 405x5 on Oct 15, 2022 13:01:59 GMT -5
You gents should return to the OP post and re-read. All he’s talking about is what an Amazon sold product claims it MIGHT do then asks if anyone has tried it on something other than guitar 🎸 pickups. How did we get here? If I were to try anything mentioned on this thread I would need to “break” something first, then see if any of this stuff could fix it. I could only add that if you were enamored with toy train sets as a kid you would have fun with those lifters that LOOK like something straight out of my old Lionel or American Flyer toys.
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Post by JKCashin on Oct 19, 2022 22:15:15 GMT -5
Wouldn't RF noise be outside the frequency range that we care about? I'll let KeithL answer that one. The simple answer is "yes, RF noise is outside the limits of human hearing." But... Some amplifiers may be sensitive to having RF at their outputs. If the amplifier is affected, the audio band may suffer. Oh that's a good point!
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Post by KeithL on Oct 20, 2022 9:51:36 GMT -5
Yes and no. It is certainly possible for noise outside the audio band to get into the feedback loop of an amplifier via the speaker outputs. This used to be a relatively common issue in the early days of solid state amps. And it was absolutely an issue with vintage tube amps. (And I guess with some poorly designed modern ones too.) However, to be quite blunt, it should not be an issue with any reasonably well designed modern amplifier. Modern amplifiers are specifically designed with gain that decreases at high frequencies starting well outside the audio band. This serves several purposes... one of which is to prevent this sort of issue. So, to be fair, it could happen. And it is one of those things you take into account when designing an amplifier... But, in practice, I haven't seen a commercial amplifier that suffered from this problem in literally decades. (I guess I might consider it... if my neighbor had a 500 watt Ham radio transmitter... or on a stage with lots of wireless microphones around... but not otherwise.) This is another one of those "solutions looking for a problem" on which so many audiophiles waste so much money... (At least, in this case, it doesn't cost much.) It's also worth remembering that adding shielding to cables adds capacitance... And that added capacitance can also cause problems for some amplifiers... (Not to mention the obvious consequences if any of that shielding foil manages to become exposed and touch anything it shouldn't.) I guess a good truism might be: "It's not always a good idea to fix problems you don't have - because every solution has the potential to create whole new problems." I'll let KeithL answer that one. The simple answer is "yes, RF noise is outside the limits of human hearing." But... Some amplifiers may be sensitive to having RF at their outputs. If the amplifier is affected, the audio band may suffer. Oh that's a good point!
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Post by KeithL on Oct 20, 2022 10:22:45 GMT -5
I'm sorry but... Yeah... it's advertising speak... and cable manufacturers are right at the head of the pack when it comes to promoting snake oil. Now, to be fair, many of them probably believe what they saying... I guess I would simply say that "they tend to be a superstitious bunch" in general (and even real engineers are not totally immune from this) And I wouldn't rule out the possibility that a few of them are even promoting things that have technical merit... Now... in this case... Obviously any two electrical conductors, separated by a gap or insulator, are capacitively coupled together. So, at this very moment, the keyboard I'm typing on is capacitively coupled to my desk, the floor, and my car out in the parking field. You could definitely calculate the amount of coupling in each case, based on the electrical characteristics of each item, although you might or might not be able to measure it. And, likewise, a speaker cable sitting on a floor is "capacitively coupled to that floor". And changing the distance between it and the floor will change that coupling in some ways. And, in that case, I suspect that, with the proper equipment, you could actually measure it. In this case the proper equipment would probably be a good quality TDR (time domain reflectometer). (A TDR can actually not only tell you whether a cable is "good" or not... but, if not, where and what sort of impedance variation is present.) But I would be willing to bet a very large sum of money that... With any normal consumer amplifier... Cable risers will NOT produce an effect that will be audible to any human being... (And I will not be inclined to accept claims to the contrary without proof of some sort.) (A real double blind test, showing that a statistically significant number of listeners can actually hear a difference, would be a good start.) Note that I absolutely agree that you should listen for yourself and report what you hear. But I will consider your results to be "personal and subjective". (If you actually did a real, properly designed and conducted, double-blind test then they would rise to "personal and OBJECTIVE".) I should also point out a rather famous quote by Carl Sagan which goes: "“extraordinary claims require extraordinary evidence”. And I'm pretty sure that any qualified electrical engineer would agree that this is quite an extraordinary claim. OK - Let's cut to the chase: I agree that KeithL is an expert on all things audio and does know far more than I on every audio topic. HOWEVER, I am also in the middle of a cable review for a major cable manufacturer and am in direct contact with the gentleman who designs the cables. The company is one of the largest in the audio field, and offers speaker wires in every price category. The designer says about cable risers: "Cable risers reduce the amount of RF noise that capacitively couples into the speaker cables through all solid flooring materials. Successfully designed and properly used, cable risers will preserve valuable low-level detail for more natural, dynamic, involving performance." Yes, it IS "advertising speak," but there is no ambiguity. He recommends cable risers - KeithL doesn't. Now neither KeithL NOR the cable designer sells cable risers, so neither has any financial motivation to lie or exaggerate. So I now have two experts telling me diametrically opposing things. Which "expert" is to be believed? The easiest solution is to listen for myself and then report what I hear. And in spite of the fact that not even experts agree on this topic, I still have to contend with ignorant yahoos trying to tell me how foolish I look and how I know nothing... Go figure. Glenn Young (aka Boomzilla)
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Post by 5channels on Oct 20, 2022 10:30:18 GMT -5
A true insider knows, it's not snake oil, rather snake grease that does the trick. It's all about viscosity, audio viscosity. 😉
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Post by Boomzilla on Oct 20, 2022 10:34:52 GMT -5
Hi @keithl -
I’d agree with everything you said with one glaring (and rather important) exception… You said you’d accept a double-blind test where a statistically-significant number of participants could reliably hear differences. I’d also accept that - but that bar is too high. I contend that if even ONE participant can reliably hear differences, then there IS a difference! Now that one listener could not be in one or even two standard deviations from the mean (otherwise it might be random chance) - but if that one listener can consistently hear differences, they exist.
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Post by marcl on Oct 20, 2022 10:43:24 GMT -5
keithl boomzilla
Sorry, my EE degree is a bit long in the tooth ... has anyone ever explained in engineering terms how RF noise capacitively coupled (or even hard wired!) to a speaker wire could possibly result in an effect that would be audible to any human?
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Post by KeithL on Oct 20, 2022 10:52:50 GMT -5
You do make an excellent point... but, to be fair to audiophiles, I would add a bit of qualification to my reply. (Whenever I see this sort of question I always assume a few unspoken conditions.) Regardless of the experience of the limited number of folks on this forum... I would definitely assert that, at some point in the past, I myself have solved noise problems by adding shielding, and quite probably that sometimes involved cables. It's pretty common to add shielding inside components to eliminate or reduce noise issues. Although I cannot say, and don't remember, whether I've ever done so specifically to an external interconnect or power cable. I can also assert that, in the past, I have encountered situations where swapping interconnects or power cables had solved a noise problem. (If you have a poorly shielded cable you're usually far better off changing it for a better cable than trying to fix the one you have.) (The only exception would be if the cable is soldered in place or uses custom connectors in such a way that replacement isn't a viable option.) But... on to those unspoken conditions... To me "the full expanded question" is: "Is adding extra shielding to an interconnect or power cable likely to improve the signal quality in a situation where there is currently no known or audible noise problem?" (If a specific noise problem was present we would expect more details we could use to determine whether additional shielding would be likely to solve it.) And the answer to THAT "expanded" question is: "It's remotely possible, but extremely doubtful, that adding shielding to a cable that has no known noise problem will "improve the sound" in some unspecified way." I find that the audio industry is saturated with unnecessary products that provide solutions to problems that don't actually exist to begin with. And the process of selling those products almost universally starts with convincing audiophiles that they have some sort of subtle problem that they never knew they had. Usually followed by a long technical explanation designed to convince them that they "should" have the problem and "just haven't noticed it so far". (Which, if you've read any books on technical marketing, is a well known strategy to convince people to imagine things that don't really exist.) In this case we're talking about an inexpensive product... Which does in fact serve a useful purpose in certain applications... And the only question is whether adding it in situations where it really isn't necessary will somehow "improve something". (And the simple answer is "probably not".) And, yes, I do agree that, in some contexts, "cable lifters look cool"... But we need to be careful to keep "they look cool" and "they produce some actual audible benefit that would justify the cost" distinct and separate from each other. As I mentioned in another post... ESPECIALLY IN THE AUDIOPHILE PRODUCT MARKET...There is a distinct tendency to market products that look or seem cool... But to then add bogus technical claims - clearly intended to give audiophiles a way to rationalize the cost of whatever they're selling. Nobody ever seems to say: "You should buy this $200 speaker cable just because it looks cool and feels nice in your hand when you work with it". (As far as I'm concerned that is a perfectly good reason to buy something... and doesn't require phony justification... and I consider that all the time when purchasing tools and such.) Also, to be fair, I prefer to have my speaker cables out of the way... I don't care what they look like and I have no specific desire to look at them day to day... And cable lifters force you to do the exact opposite... and put them where they're very easy to trip over. (But THAT is just my personal preference.) You gents should return to the OP post and re-read. All he’s talking about is what an Amazon sold product claims it MIGHT do then asks if anyone has tried it on something other than guitar 🎸 pickups. How did we get here? If I were to try anything mentioned on this thread I would need to “break” something first, then see if any of this stuff could fix it. I could only add that if you were enamored with toy train sets as a kid you would have fun with those lifters that LOOK like something straight out of my old Lionel or American Flyer toys.
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Post by KeithL on Oct 20, 2022 11:07:17 GMT -5
To answer your question... In theory RF noise, entering through the speaker cable, could be coupled back to the input through the feedback loop. (The feedback loop does provide a path from the output directly back to the input stage or close to it.) And, at that point, it could cause the input stage to act oddly. I have actually heard of cases where powerful AM broadcasts were picked up by a speaker cable... Then found their way back to the differential pair at the input... Where the signal was "detected" (rectified) by the junction of the input transistor... And you ended up being able to hear the station out of the speakers. (And, in theory, if the result was ultrasonic noise instead, it could cause distortion as well.) Now, to be fair, the last time I actually HEARD this happen personally was on a cheap PA amp... And it was about fifty years ago... (I think it actually had germanium output transistors.) It was also clearly audible... (and you could hear what local station was causing it). So it is theoretically possible, even with a modern amp, especially if it was defective. And it would be more likely with tube gear because tubes tend to amplify very high frequencies especially well. (But it's clearly not something I would worry about unless I actually noticed it happening.) keithl boomzilla Sorry, my EE degree is a bit long in the tooth ... has anyone ever explained in engineering terms how RF noise capacitively coupled (or even hard wired!) to a speaker wire could possibly result in an effect that would be audible to any human?
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Post by KeithL on Oct 20, 2022 11:36:49 GMT -5
I'm inclined to agree... as long as the test was truly double-blind and that result was truly consistent and reliable. The catch here is that nobody is going to do such a study. When it comes to things like speaker cables and lifters and such.... ALL we seem to get is anecdotal evidence, subjective results from sighted tests, and pseudo-scientific explanations about why we SHOULD hear something. (A few people have tried to do double-blind tests but they always turn out to be deeply flawed - or to produce no conclusive results.) (And, on occasions when certain companies have conducted demonstrations at shows, there is a long laundry list of how they deliberately biased the results to show what they want.) Note that there is in fact a perfectly logical reason why nobody bothers to conduct most of these studies. A company who sells expensive speaker cables really has no NEED to spend a lot of money on tests. The most successful "tools" for marketing this sort of product are subjective positive reviews and pseudo-scientific explanations about why we SHOULD hear something. People buy this sort of product because they expect to hear a difference; and, once they have "sunk cost" in the product, they have a bias to hear that difference. We might assume that, if the company had actual measurements, or actual valid study results, they would publish them... but they never do. (We'll never know whether they tried, and got poor results, or whether they simply saw no need to spend the money.) Now, of course, the company who sells $20 speaker cables would probably benefit from a study showing that "theirs sounded just as good as the $200 ones"... But in fact they have little incentive to spend a lot of money to conduct a test that proved exactly what most people already believe anyway. (And, with a $20 product, they don't have the budget or the incentive to spend a lot of money convincing you to buy it.) A similar issue exists with magazines. Most magazines make their income from advertising or viewership. Clearly no magazine that accepts advertising from companies who make expensive speaker cables has any incentive to conduct tests showing that they're worthless. They also have little incentive to demonstrate how good the $20 cables are - because the company who sells those isn't buying expensive ads. Therefore they strike a balance between "being controversial and interesting" and "not pissing off potential advertisers and audiophiles with strong opinions". (It's really difficult to stay in business these days publishing unbiased reviews in a subscriber-supported magazine.) (Likewise, even for a website that is monetized on views, it's not good business to continually repeat "you were right - don't waste your money".) It's also worth mentioning another issue... And that is that, in most of these situations, the manufacturer is suggesting, or outright claiming "an obvious difference that can be easily heard". Even assuming that one single listener can reliably hear a difference in a real double-blind test there is still the issue of how that affects others. If there is a difference so tiny that only one guy on the entire planet can hear it... then they're lying when they say it's obvious... and the rest of us would be wasting our money. (Of course, in that case, it would be perfectly fair for that guy to report what HE hears.) This is another common sales tactic... suggest that "the difference is there if you just listen hard enough" and discourage people from "admitting" that THEY don't hear a difference. (And, incidentally, this tactic works great - whether there really is a difference that anybody at all can hear or not.) Hi @keithl - I’d agree with everything you said with one glaring (and rather important) exception… You said you’d accept a double-blind test where a statistically-significant number of participants could reliably hear differences. I’d also accept that - but that bar is too high. I contend that if even ONE participant can reliably hear differences, then there IS a difference! Now that one listener could not be in one or even two standard deviations from the mean (otherwise it might be random chance) - but if that one listener can consistently hear differences, they exist.
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Post by 405x5 on Oct 20, 2022 14:32:27 GMT -5
You do make an excellent point... but, to be fair to audiophiles, I would add a bit of qualification to my reply. (Whenever I see this sort of question I always assume a few unspoken conditions.) Regardless of the experience of the limited number of folks on this forum... I would definitely assert that, at some point in the past, I myself have solved noise problems by adding shielding, and quite probably that sometimes involved cables. It's pretty common to add shielding inside components to eliminate or reduce noise issues. Although I cannot say, and don't remember, whether I've ever done so specifically to an external interconnect or power cable. I can also assert that, in the past, I have encountered situations where swapping interconnects or power cables had solved a noise problem. (If you have a poorly shielded cable you're usually far better off changing it for a better cable than trying to fix the one you have.) (The only exception would be if the cable is soldered in place or uses custom connectors in such a way that replacement isn't a viable option.) But... on to those unspoken conditions... To me "the full expanded question" is: "Is adding extra shielding to an interconnect or power cable likely to improve the signal quality in a situation where there is currently no known or audible noise problem?" (If a specific noise problem was present we would expect more details we could use to determine whether additional shielding would be likely to solve it.) And the answer to THAT "expanded" question is: "It's remotely possible, but extremely doubtful, that adding shielding to a cable that has no known noise problem will "improve the sound" in some unspecified way." I find that the audio industry is saturated with unnecessary products that provide solutions to problems that don't actually exist to begin with. And the process of selling those products almost universally starts with convincing audiophiles that they have some sort of subtle problem that they never knew they had. Usually followed by a long technical explanation designed to convince them that they "should" have the problem and "just haven't noticed it so far". (Which, if you've read any books on technical marketing, is a well known strategy to convince people to imagine things that don't really exist.) In this case we're talking about an inexpensive product... Which does in fact serve a useful purpose in certain applications... And the only question is whether adding it in situations where it really isn't necessary will somehow "improve something". (And the simple answer is "probably not".) And, yes, I do agree that, in some contexts, "cable lifters look cool"... But we need to be careful to keep "they look cool" and "they produce some actual audible benefit that would justify the cost" distinct and separate from each other. As I mentioned in another post... ESPECIALLY IN THE AUDIOPHILE PRODUCT MARKET...There is a distinct tendency to market products that look or seem cool... But to then add bogus technical claims - clearly intended to give audiophiles a way to rationalize the cost of whatever they're selling. Nobody ever seems to say: "You should buy this $200 speaker cable just because it looks cool and feels nice in your hand when you work with it". (As far as I'm concerned that is a perfectly good reason to buy something... and doesn't require phony justification... and I consider that all the time when purchasing tools and such.) Also, to be fair, I prefer to have my speaker cables out of the way... I don't care what they look like and I have no specific desire to look at them day to day... And cable lifters force you to do the exact opposite... and put them where they're very easy to trip over. (But THAT is just my personal preference.) You gents should return to the OP post and re-read. All he’s talking about is what an Amazon sold product claims it MIGHT do then asks if anyone has tried it on something other than guitar 🎸 pickups. How did we get here? If I were to try anything mentioned on this thread I would need to “break” something first, then see if any of this stuff could fix it. I could only add that if you were enamored with toy train sets as a kid you would have fun with those lifters that LOOK like something straight out of my old Lionel or American Flyer toys. There are only two instances I can recall since I’ve been at this where I had to address noise and/or interference issues by doing SOMETHING that wasn’t already taken care of by the state of the art itself…. The first is rather archaic, and that’s turntable grounding which back in the day could be a significant nuisance, though usually an easy fix once isolated. The second was actually at the video end in the early days of HT and having a “peaceful coexistence” between CRT monitors and the need then, for magnetically shielded drivers. It was a valid issue but the fix, though usually effective was not an exacting science by any means. I suspect a lot of monitors back then would have been unaffected by it because of the proximity of the driver magnets to the guns in those monitors.
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Post by Boomzilla on Oct 20, 2022 17:10:28 GMT -5
I'm sorry but... Yeah... it's advertising speak... and cable manufacturers are right at the head of the pack when it comes to promoting snake oil. Now, to be fair, many of them probably believe what they saying... I guess I would simply say that "they tend to be a superstitious bunch" in general (and even real engineers are not totally immune from this) And I wouldn't rule out the possibility that a few of them are even promoting things that have technical merit... Now... in this case... Obviously any two electrical conductors, separated by a gap or insulator, are capacitively coupled together. So, at this very moment, the keyboard I'm typing on is capacitively coupled to my desk, the floor, and my car out in the parking field. You could definitely calculate the amount of coupling in each case, based on the electrical characteristics of each item, although you might or might not be able to measure it. And, likewise, a speaker cable sitting on a floor is "capacitively coupled to that floor". And changing the distance between it and the floor will change that coupling in some ways. And, in that case, I suspect that, with the proper equipment, you could actually measure it. In this case the proper equipment would probably be a good quality TDR (time domain reflectometer). (A TDR can actually not only tell you whether a cable is "good" or not... but, if not, where and what sort of impedance variation is present.) But I would be willing to bet a very large sum of money that... With any normal consumer amplifier... Cable risers will NOT produce an effect that will be audible to any human being... (And I will not be inclined to accept claims to the contrary without proof of some sort.) (A real double blind test, showing that a statistically significant number of listeners can actually hear a difference, would be a good start.) Note that I absolutely agree that you should listen for yourself and report what you hear. But I will consider your results to be "personal and subjective". (If you actually did a real, properly designed and conducted, double-blind test then they would rise to "personal and OBJECTIVE".) I should also point out a rather famous quote by Carl Sagan which goes: "“extraordinary claims require extraordinary evidence”. And I'm pretty sure that any qualified electrical engineer would agree that this is quite an extraordinary claim. I'd agree with you, KeithL - Differences in audio (or digital) cables are vanishingly small. The $$$ that are spent on esoteric minutia are astounding. IF you have really good ears, IF you have a thoroughly treated, symmetrical listening room, IF you have premium electronics, and IF you have the best of speakers, then (and only then) should fancy cables even be considered. And even then, the benefits are really, really small in comparison to the cost. In most cases differences that are heard make audio "different" but not necessarily better. That said, I have encountered two brands of speaker wires that I thought made noticeable differences in the sound of the speakers. Those two were the original Kimber Kable (did a good job of preventing highs from screeching on some of the speakers available at that time) and Nordost - The cheap flatline cables emphasized the highs. It's also painfully true that Manufacturers are bullies when it comes to the press. Publish a single neutral review of a company's products, and you'll never get a chance to review that brand again (and that's with a neutral review - not even a negative one). With many magazines, websites, and reviewers, many (most?) manufacturers studiously adhere to the "I'll scratch your back if you'll scratch mine" attitude. The higher priced the product, the more the manufacturer wants ONLY rave reviews. At this point, I've had a LOT of reviews that went unpublished because the publisher feared the wrath of the manufacturer ("but they're a big advertiser..."). I have the luxury of being able not to worry about it. I write what I hear, and let the chips fall where they may. I don't earn a living in this field and have absolutely nothing to lose if I alienate the manufacturer, the publisher, or even the readers. I write for the fun of it and will continue to do so while I can. That being the case, there's no reason for me to avoid controversy. Cheers - Glenn
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Post by KeithL on Oct 20, 2022 17:11:24 GMT -5
Yes... most properly designed modern gear is specifically designed to avoid this sort of well known problems. However... a bit of trivia for you. With CRT screens the problem with speaker magnets is not because of the electron guns. (A strong magnetic field could affect the aim of the electron gun but that would be temporary.) The real nasty issue involved only color CRTs. On color CRTs the three colors of screen phosphors are arranged in a pattern - either three dots in a triangle or some pattern of stripes. Inside the tube, behind the screen, is something called a screen mask... which is a metal sheet with rows of small holes in it. The electron beam from each color gun hits this screen from a slightly different angle... And, because of how the holes in the mask match up with the phosphor dots, the beam from each gun can only strike phosphor dots that go with that gun. So, for example, based on the angle between the red gun and the holes, the beam from that gun can only hit dots of red phosphor. This is pretty ingenious because, even if the beam isn't perfectly sharp, and hits multiple phosphor sites, it will never hit sites of the wrong color. EXCEPT that, because of various mechanical limitations, this screen mask was always made out of a thin sheet of steel. And... err... steel gets magnetized very easily... and any tinge of magnetism in the screen mask would cause "color stains" on the picture. Color CRTs actually almost always have a "degaussing coil" wrapped around the front edge of the tube near the screen mask. (Which is why you shouldn't put your credit cards near the front edge of a big color CRT - because it might erase their magnetic stripes.) This coil fires a pulse of alternating magnetic field each time the TV is turned on... This is necessary to erase the slight permanent magnetism that the screen mask might pick up from the Earth's magnetic field. But the field from an unshielded speaker magnet is a LOT stronger... Actually touching the screen with a magnet can produce such a strong effect that the degaussing coil is unable to erase it... And, if that happens, the resulting smear of color may persist for weeks before it disappears, or require a visit from a technician with an external degaussing coil. (The degaussing gadget is run around the edge of the tube multiple times in what was sometimrs jokingly described as "the witch doctor dance".) Even the field generated by a strong unshielded speaker magnet several feet away is enough to risk distorting the picture over time. Luckily this ONLY affects color CRTs... It didn't affect black and white CRTs (or green or amber monochrome screens)... And it doesn't have any effect on modern flat-screen technologies. The deflection coils in a color TV are copper and so don't hold any magnetism when not energized. And the small "convergence adjustment magnets" used on some tubes are really weak... And they're positioned on the neck of the tube well away from the front. You do make an excellent point... but, to be fair to audiophiles, I would add a bit of qualification to my reply. (Whenever I see this sort of question I always assume a few unspoken conditions.) Regardless of the experience of the limited number of folks on this forum... I would definitely assert that, at some point in the past, I myself have solved noise problems by adding shielding, and quite probably that sometimes involved cables. It's pretty common to add shielding inside components to eliminate or reduce noise issues. Although I cannot say, and don't remember, whether I've ever done so specifically to an external interconnect or power cable. I can also assert that, in the past, I have encountered situations where swapping interconnects or power cables had solved a noise problem. (If you have a poorly shielded cable you're usually far better off changing it for a better cable than trying to fix the one you have.) (The only exception would be if the cable is soldered in place or uses custom connectors in such a way that replacement isn't a viable option.) But... on to those unspoken conditions... To me "the full expanded question" is: "Is adding extra shielding to an interconnect or power cable likely to improve the signal quality in a situation where there is currently no known or audible noise problem?" (If a specific noise problem was present we would expect more details we could use to determine whether additional shielding would be likely to solve it.) And the answer to THAT "expanded" question is: "It's remotely possible, but extremely doubtful, that adding shielding to a cable that has no known noise problem will "improve the sound" in some unspecified way." I find that the audio industry is saturated with unnecessary products that provide solutions to problems that don't actually exist to begin with. And the process of selling those products almost universally starts with convincing audiophiles that they have some sort of subtle problem that they never knew they had. Usually followed by a long technical explanation designed to convince them that they "should" have the problem and "just haven't noticed it so far". (Which, if you've read any books on technical marketing, is a well known strategy to convince people to imagine things that don't really exist.) In this case we're talking about an inexpensive product... Which does in fact serve a useful purpose in certain applications... And the only question is whether adding it in situations where it really isn't necessary will somehow "improve something". (And the simple answer is "probably not".) And, yes, I do agree that, in some contexts, "cable lifters look cool"... But we need to be careful to keep "they look cool" and "they produce some actual audible benefit that would justify the cost" distinct and separate from each other. As I mentioned in another post... ESPECIALLY IN THE AUDIOPHILE PRODUCT MARKET...There is a distinct tendency to market products that look or seem cool... But to then add bogus technical claims - clearly intended to give audiophiles a way to rationalize the cost of whatever they're selling. Nobody ever seems to say: "You should buy this $200 speaker cable just because it looks cool and feels nice in your hand when you work with it". (As far as I'm concerned that is a perfectly good reason to buy something... and doesn't require phony justification... and I consider that all the time when purchasing tools and such.) Also, to be fair, I prefer to have my speaker cables out of the way... I don't care what they look like and I have no specific desire to look at them day to day... And cable lifters force you to do the exact opposite... and put them where they're very easy to trip over. (But THAT is just my personal preference.) There are only two instances I can recall since I’ve been at this where I had to address noise and/or interference issues by doing SOMETHING that wasn’t already taken care of by the state of the art itself…. The first is rather archaic, and that’s turntable grounding which back in the day could be a significant nuisance, though usually an easy fix once isolated. The second was actually at the video end in the early days of HT and having a “peaceful coexistence” between CRT monitors and the need then, for magnetically shielded drivers. It was a valid issue but the fix, though usually effective was not an exacting science by any means. I suspect a lot of monitors back then would have been unaffected by it because of the proximity of the driver magnets to the guns in those monitors.
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Post by leonski on Oct 25, 2022 0:34:18 GMT -5
IF , (doubtful) you need to wrap wires in copper? GROUND only at the 'feed' end...... You may start buying shielded power cable....so some 'bad stuff' may not enter the system in the 1st place...... BUT? Here is a little something which is a good help at what I'll bet is a much lower cost. en.wikipedia.org/wiki/Ferrite_bead
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Post by leonski on Oct 25, 2022 13:49:44 GMT -5
Several Beldin DIY articles dealing with the 2 main power cables they sell in bulk. A 12ga which is fairly $$ and a 14 which is FINE for lower powered amps and anything which is lowered powered. The good news is the 14 is not all that much $$. Attach th eground ONLY at the 'feed' end, so any RF goes to ground at that end....not into the device which the cord services.
Make certain your HOUSE GROUND is up to snuff.....
For RCA I'd try ferrite BEADS.......and use balanced whereever possible....due to common mode noise reduction while in MY system, I also use OPTICAL whenever possible since with No electrical connection it is tough to get RFI.....or EMI or whatever you want to call it.....
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Post by leonski on Oct 31, 2022 16:14:01 GMT -5
Magnetic noise, so far as I understand it, is usually 60 Hz. hum that is picked up form adjacent wiring and equipment. This is more common in stage applications due to the great number and close proximity of signal and power cables (and the proximity of transformers). The easiest way to protect against such hum (in order of preference for home audio systems) is to: 1. Dress signal and power cables away from each other to the extent possible 2. If distance between wires can't be increased, then try to cross the signal and power cables at right angles to each other (minimizing their interaction) 3. If neither of the above work, buy shielded signal cables to minimize hum pickup Radio frequency (RF) noise happens at much higher frequencies, and can (rarely) have unpredictable effects on amplifiers. Again, this is more common in stage amplification due to the large number of lighting devices, many of which can emit RF. In home audio, it is usually caused by close proximity to a strong RF emitter such as a cell phone tower, radio station antenna, wireless modem, or CB antenna. Use of shielded cables is the usual solution. Some also recommend the use of "cable risers" that are non-conductive devices that prevent the speaker cables (usually) from touching the floor. The theory behind the use of cable risers is akin to the experience those of us who are old enough had with "rabbit ear" television antannas. When you'd touch the antenna, the reception would improve because your body was essentially becoming part of the antenna, and the greater surface area was more effective at catching radio waves. The "cable lifter" theory is that if your speaker cables are in contact with the floor, the added antenna surface area (the floor) catches more radio waves. Cable lifters need not be expensive. I use 0.68 cent "rebar chairs" from my local Lowes store. Made of non-conductive polypropylene, a few of these will keep your speaker wires away from the floor. Cheers - Boomzilla If I were SERIOUSLY interested in cable lifters? I'd go buy a bunch of LEGO and make little colorful 'trestles'. A drop of hot blue holding each together would be nice. Don't glue until you settle on a design.......
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Post by Boomzilla on Oct 31, 2022 17:06:00 GMT -5
One of my audio amigos says he does hear a difference between on the floor and in the air but...
1) He has a LOT more cable length than I do. All his equipment is to one side of the room, and for the far speaker, he probably has thirty feet of wire. My equipment rack is centered and I've no more than eight or 10 feet of wire per side.
2) He has some kind of deep-pile carpet over some kind of REALLY thick pad underneath. I have a hard floor directly over a concrete slab.
3) He has a LOT more room treatment than I do, and
4) He listens to his speakers essentially "near field" in his room - I don't.
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Post by ttocs on Oct 31, 2022 17:19:58 GMT -5
2) He has some kind of deep-pile carpet over some kind of REALLY thick pad underneath. Carpet. An energy storage device. A capacitor? It releases energy when two people shake hands in the winter in cold, dry climates. If I had carpet I would raise the cables off of it.
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Post by leonski on Nov 1, 2022 1:02:40 GMT -5
OH! BTW......while a lot of noise IS some harmonic of 60hz, sometimes it just ain't so. I've received local AM radio thru my stereo. Like a Filling acting as a detector. Ham Radio guys (I'm KN6UZT, in another life) have to meet certain requirements IF a neighbor calls 'em on noise in electronics. This interferrence is taken seriously......WILLFUL interference may get your ticket pulled. Poor station practices may result in such interference. Bad ground? Frayed Insulation? That sort of thing. Carpet......espeically in, as you note, cooler and DRY climates, can build up QUITE a charge. I've zapped myself to the point where someone standing 5 feet away HEARD IT. I HATE Static. When I was a kid? Chicago in the WINTER was the worst. And yes, walking across the carpet was DEATH. Even the cat avoided it....How do you GROUND a cat? And in microelectronics, especially assembly? Everybody wears a grounding wrist strap which they plug INTO the station they are working to provide a ground path..... www.fcc.gov/consumers/guides/interference-radio-tv-and-telephone-signals
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