garyrc Posted September 27, 2010 Share Posted September 27, 2010 We are about to lay new carpet. The speaker cable must be laid over the carpet or,perhaps laid directly on the floor, in channels cut in the rug pad (or doublerug pad, if necessary). This part of the room gets zero foottraffic. Little tripods or overhead strings to hold the cable off of thefloor are out of the question. We hear from MapleShade (and others in thegrapevine) that "laying speaker cables, interconnects, and AC power cordson an artificial fiber carpet will immediatelydull the sound of your stereo." Apparently, they think that there is some kindof electrical effect brought about by the artificial fiber … even though I tendto doubt this, if there is some subtle audible effect, we might as well avoid it since we are laying new rug. So, if the effect is real, does this mean: a) A wool rug with a latex pad (naturalrubber) would not dull the sound? A wool rug with a jute pad would not dullthe sound? How can the carpet affect what is happeningin the speaker cable? Quote Link to comment Share on other sites More sharing options...
DrWho Posted September 28, 2010 Share Posted September 28, 2010 We hear from MapleShade (and others in the grapevine) that "laying speaker cables, interconnects, and AC power cords on an artificial fiber carpet will immediately dull the sound of your stereo." Apparently, they think that there is some kind of electrical effect brought about by the artificial fiber … even though I tend to doubt this, if there is some subtle audible effect, we might as well avoid it since we are laying new rug. Will MapleShade or "others in the grapevine" provide you with a true technical explanation backed by data? The reason I ask is because I checked out their website and noticed that some of their marketing material on speaker cables doesn't agree with well established electrical theory. I'll give them benefit of the doubt that their marketing team has run wild, but I would fine it surprising for an engineer or scientist to claim that carpet would exhibit appreciable electrical impact on the signal traveling through a speaker wire. Just for kicks, let's run a few numbers.... The output impedance of your amplifier should be well under 10 ohms...it's usually in the 0.1 ohm range, or even lower, but let's just call it 10 ohms because that makes the analogy worst case. The impedance of your speaker cable jacket should be on the order of 100,000,000 ohms at typical speaker voltages. The electrical impedance of carpet is also going to be on the order of 100,000,000 ohms. So at DC, we have a fairly straightforward voltage divider where the electrical impedance of the speaker cable jacket and the carpet are going to present a 0.000005% reduction in the output of the signal, which comes out to about a 0.0000004dB reduction in output. A 1dB change in output is supposed to be the smallest discernable step-size, and we're talking artifacts on the order of over one million times smaller...even using an absolute worst case scenario. Even if you were using ESD Carpet, its impedance is still in the 1,000,000 ohm range, but the 100,000,000 ohm resistance of your cable insulation is still going to swamp that out. The electrical impedance of the human body is on the order of 500,000 ohms, so if you want to do a quick experiment for yourself, have someone sitting by your speaker wires and see if you can hear when they touch and let go of the speaker wire. Granted, these quick numbers are only back of hand DC calculations, but I see absolutely no data to support that the impedance of carpet is lower at higher frequencies...and even if it was capacitive at higher frequencies, it still has to work against the ESR of the speaker wire insulation. There's also no field to be generated on the other side of the carpet, so there really can't be any energy storage. So all that to say, I really wouldn't worry about the sonic effects of your carpet. I would, however, recommend purchasing a plenum rated cable since it'll be a permanent install under the rug. Belden makes some great low-inductance twisted pair speaker cable with a plenum jacket for very reasonable prices. But given your application, I might also recommend looking into flat cable so that the carpet can lay perfectly flat. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted September 29, 2010 Share Posted September 29, 2010 Unless the carpet has metal fibers there should be no effect. Even if it did, the difference should small or unnoticeable. I like your idea about cutting channels in the pad and laying the carpet on top of the cable. Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted September 29, 2010 Share Posted September 29, 2010 The electrical impedance of the human body is on the order of 500,000 ohms, so if you want to do a quick experiment for yourself, have someone sitting by your speaker wires and see if you can hear when they touch and let go of the speaker wire. Love it!!! Mike, That's absolutely one of the greatest rebuttals to snake oil marketing I've ever seen!!! [Y][Y][Y] But then again.... what happens if a fat chick sits on the cable? Adipose tissue has a higher conductivity rate as it's the rough equivalent of "salt pork"? [6] [H] Quote Link to comment Share on other sites More sharing options...
Islander Posted September 29, 2010 Share Posted September 29, 2010 High BMI = low M appeal BTW, that's where Emma Peel of The Avengers got her name. The producers figured that adding a babe in a tight leather jumpsuit would add male appeal to the show. They were right! Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted September 30, 2010 Share Posted September 30, 2010 Fascinating!! [Y] Quote Link to comment Share on other sites More sharing options...
DrWho Posted September 30, 2010 Share Posted September 30, 2010 But then again.... what happens if a fat chick sits on the cable? Adipose tissue has a higher conductivity rate as it's the rough equivalent of "salt pork"? Wow, now there's an image! Haha. Well I can certainly say it won't sound as good, but not for reasons of electrical behavior in the wire... [] Quote Link to comment Share on other sites More sharing options...
mark1101 Posted September 30, 2010 Share Posted September 30, 2010 It woud probably cost less to buy a "real" rug than expensive cables. My personal opinion is that the hypothesis is complete BS. Do a test. Lay one speaker wire on the artificial rug and arrange the other so it is not on the rug and see if you can hear a difference. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 30, 2010 Share Posted September 30, 2010 But then again.... what happens if a fat chick sits on the cable? I think it's dependant on the Fs of the thong. Quote Link to comment Share on other sites More sharing options...
RichardP Posted September 30, 2010 Share Posted September 30, 2010 There is such as thing as ribbon cable, flat enough (1/10") to put under a carpet without needing channels. Check out Parts Express, and probably other sources. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted September 30, 2010 Share Posted September 30, 2010 By the way.........what's the difference between artificial fiber and real fiber when it comes to rugs? Is nylon a real or artificial fiber? Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted September 30, 2010 Share Posted September 30, 2010 No Fat Chicks!!!! Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted October 1, 2010 Share Posted October 1, 2010 No Fat Chicks!!!! Oh come'on!!! They need music too!!! [6] Quote Link to comment Share on other sites More sharing options...
garyrc Posted October 1, 2010 Author Share Posted October 1, 2010 Thanks everyone! I'll run some tests, but it almost must be BS. Mike: great answer! Mark1101: Nylon is synthetic... i think it was the first! In the '40s they marketed "nylon needles" the "miracle synthetic" for one's phonograph. My old Webster Chicago (Webcor) I had when about 4 years old had one. They lasted about a month. Quote Link to comment Share on other sites More sharing options...
WMcD Posted October 2, 2010 Share Posted October 2, 2010 Gary, this is certainly BS. Let me tell a story. Many years ago the office had some interns vising for a summer. Very intelligent people and educated in many ways, but not educated in the sciences. Let me say: they were willing to believe in new age notions which have the subtext that ancient truths have been unjustly suppressed by modern science, or that the new age notions are advances over present knowledge. One of the interns got an ear ache. So they went out and tried and ear candle. http://en.wikipedia.org/wiki/Ear_candle Of course it did no good. But then they asked me what I thought about ear candles. This was before Wikipedia.. What I thought was, "Don't you people have the sense that God Gave a Goose?" I e-mailed that back to them. No response and I suppose they were a little insulted. That is what I think about the carpet question -- or better stated, anyone who would propose the effect to marks. I hope you're not insulted. Smile. Edit. We all have to be a bit careful. Some of us here have been fooling around with wires and electonics for decades and thus have a good feel for BS. OTOH, there are hucksters out there who make authoritarian statements which are transparent fabrications. Newcomes can't always detect it. Wm McD Quote Link to comment Share on other sites More sharing options...
jtnfoley Posted October 2, 2010 Share Posted October 2, 2010 By the way.........what's the difference between artificial fiber and real fiber when it comes to rugs? Is nylon a real or artificial fiber? And, perhaps more importantly, if a carpet is both real AND oxygen-free will the sound improve? Quote Link to comment Share on other sites More sharing options...
Daniel Marshall Posted February 3, 2012 Share Posted February 3, 2012 Hi I need of carpet and rugs Quote Link to comment Share on other sites More sharing options...
Daniel Marshall Posted February 3, 2012 Share Posted February 3, 2012 You can check out my old wool rugs. It could helpful for choose your rugs. Daniel Quote Link to comment Share on other sites More sharing options...
tragusa3 Posted February 3, 2012 Share Posted February 3, 2012 The flat wire is a good suggestion. Also, are you on a wooden subfloor? If so, flat cable and routing a shallow channel into the subfloor would make the cables completely a non issue. I would not be considering two layers of pad as you mentioned earlier. Quote Link to comment Share on other sites More sharing options...
Pete H Posted February 3, 2012 Share Posted February 3, 2012 You don't need to cut channels in the pad. If the carpet pad is installed properly it will be on the inside edge of the tack strip that will grip the carpet and that won't be up against the wall either. After the tack strip and pad (go with the heaviest rebond you can afford) are installed you should be able to keep your wires just to the inside of the tack strip and have them notch the strip to allow the cable to come up tight against the base board. I would secure the wire in a couple of locations with small cable clamps that won't stick up any higher than the tack strip to make sure that the wire doesn't get over the tacks. Remember you don't walk around your house on the edge. Quote Link to comment Share on other sites More sharing options...
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