Browse Forums Home Theatre & Automation 1 Sep 07, 2012 4:18 pm Hi Guys, Just thought to share some recent experience with speaker cables I had which I thought may be useful for those who are keen in setting up a high quality audio/ Home theatre system. I have recently cabled my own theatre and was researching on speaker cable for few months before that. Got mixed reviews and feedbacks and finally decided to go with a 'Clear Sheath' speaker cable that marked as Oxygen Free Copper / 12 AWG for the 5.1 setup. I know that it's an overkill for a 4 m x 5 m room but didnt want any anxieties later. The brand is Arista / Code : SPC12, the price was 3 AUD per meter. But you could buy a 100m reel for less than 200 AUD. Pretty cheap huh ? read on.... Just before doing the cabling I suddenly thought to strip the cable a bit to see how the strands are twisted. Seemed to be fine and then I went ahead by cleaning the strands with a knife. Here goes the trick... The strands are not 100% copper (let it be OFC or not). It actually was COPPER CLAD ALUMINIUM , clearly visible to the naked eye. More closer look suggested some strands not even plated with copper correctly. I was so disappointed and returned it back to the seller. I then went for a tin-plated copper cable called 'Supra' which I believe is worth the money. Bit expensive (5$ - 7 $ / meter ), but will give you the peace of mind for sure. To be honest there are very good value for money cables even made in Australia , Tycab is one of them. Matt Walker has some stocks of them ( I'm not a friend of him but I have been to his shop few times and noted he sells some quality stuff). So the idea I had in my mind "Every cable is the same as it is OFC copper" is not true any more. You must be bit careful when buying from Ebay and in store generic brands advertized as 'Oxygen Free Copper'. I guess you can easilly detect it by the price per metre. I dont think pure copper comes at dirt cheap price. Not sure what is the impact this has on the audio quality probably Matt or Rodda can explain a bit. But personally I dont like to hook up a high end system with low quality cable which is not 100% copper be it OFC or not. cheers Re: Speaker Cable - beware Not all are the same :) 2Oct 31, 2012 3:15 pm I've got no hesitation in recommending "Selby Acoustics" for all your cable needs. They sell from their bricks & mortar store, from their web-site and they also have a store on eBay. I've used then a few times before. P_D *Standard disclaimer applies . Block settled 07 June 2011 Our little piece of the Interwebs on HomeOne....... viewtopic.php?f=31&t=48577&start=0 Re: Speaker Cable - beware Not all are the same :) 3Oct 31, 2012 7:58 pm Our cables also came from Selby, highly recommended! Built the Seaview 36 with Rawson Homes - Read about it on my blog http://lamaisondemorgan.blogspot.com.au/ Re: Speaker Cable - beware Not all are the same :) 4Dec 11, 2012 9:45 pm Thanks guys, We have 4 Bricks and mortars stores all around Australia (VIC, NSW, QLD and WA) and compared to others I think you will find our prices to be extremely competitive! Re: Speaker Cable - beware Not all are the same :) 5Dec 12, 2012 11:56 am Oxygen free cable is pointless for speaker wire and here is why: The reason some cables are made OFC is because oxygen causes pits in copper. At high frequencies, signals tend to flow over the outside of the cable (the skin effect). The pits reduce the surface area of each strand and therefore increase the resistance of the strand to the signal. This effect is only really noticeable at higher frequencies, say above 1MHz. For your speaker cables, even if you count the 4th order harmonics, you're only up to 100kHz. So there is no reason to buy OFC cable for speaker wires. You are correct that copper is a better conductor than aluminium, and therefore has a lower resistance per linear length. It could be possible that an OFC speaker wire is a better quality cable (i.e. better quality copper, better insulation etc) but simply marking it OFC means nothing for speaker cables. For your HDMI or SPDIF cables, yes OFC is a benefit. For speakers, it doesn't matter at all. It's just a marketing gimmick. Re: Speaker Cable - beware Not all are the same :) 6Dec 12, 2012 12:07 pm wokwon Oxygen free cable is pointless for speaker wire and here is why...... It's just a marketing gimmick. As I was led to believe, "In the day" OFC was in fact a big deal for some applications but with todays manufacturing processes just about ALL copper cable is oxygen free, or so close to it that it doesn't matter. But I agree, with the incredibly modest demands that audio signals put on wire, just about anything over a tight piece of string stretched between two baked-bean cans would be more than adequate*. ST *With the obvious disclaimer that the capacity of the wire needs to be up to the job required of it . Block settled 07 June 2011 Our little piece of the Interwebs on HomeOne....... viewtopic.php?f=31&t=48577&start=0 Re: Speaker Cable - beware Not all are the same :) 7Dec 12, 2012 6:15 pm wokwon, Thats an interesting analysis - what effect does oxidization have on the copper cable? Re: Speaker Cable - beware Not all are the same :) 8Dec 12, 2012 7:07 pm At work now, but I Googled it this AM and there are a few good articles on why OFC is not necessary for speaker cables. I'll have a look when I get home tonight and post some links. P_D . Block settled 07 June 2011 Our little piece of the Interwebs on HomeOne....... viewtopic.php?f=31&t=48577&start=0 Re: Speaker Cable - beware Not all are the same :) 9Dec 13, 2012 10:38 am mattwalker wokwon, Thats an interesting analysis - what effect does oxidization have on the copper cable? Same effect it has on normal copper. It develops a patina and then stops oxidising as the patina protects the underlying surface. Flexing the cable may crack the patina causing a bit more oxidation but for speaker wires, it's not a problem. Re: Speaker Cable - beware Not all are the same :) 10Dec 13, 2012 7:46 pm For your reading pleasure .......... http://forums.audioholics.com/forums/st ... opper.html Quote: Electrolytic tough-pitch (ETP) copper is an inexpensive industrial copper used for the producing wire, rods and strips. ETP copper has a nominal oxygen content of about 0.04%. .....For most applications the oxygen in ETP copper is an insignificant impurity. However, when ETP copper is heated to a temperature above around 400̊ C (752̊ F) such as when using a high temperature solder in an atmosphere containing hydrogen (found in air), the hydrogen can diffuse into the copper and react with the internally dispersed Cu20 to form steam Unless you're looking at temperatures above 400°C no so much an issue at all..... Quote: But the amount of oxygen present in conventionally annealed, non-OFC copper is so tiny that it simply isn't a factor in cable quality. We have cut into pieces of Belden coaxial cable 25-years old that have been used in radio transmission applications and found them clean and bright, completely lacking any sign of oxidation. Modern coax is better still, with nitrogen-injected foam dielectrics that keep oxygen entirely away from the center conductor. Moisture isn't an issue either http://www.aqdi.com/goldcon.htm Quote: ......... Cable resistance is the most important factor regarding speaker cables, and you don't have to worry about inductance, capacitance, velocity factor, charcteristic impedance, dielectric constant, or any of the other technical terms, as long as you keep your cables short, say, 50 feet or less, with each cable the same length! http://www.head-fi.org/t/408073/why-oxy ... etp-copper Quote: .........The copper type in a Death Valley guitar cable is anything but “regular old” copper. It is known as Electrolytic-Tough-Pitch (ETP) copper. It is the best copper to use for electrical applications, bar none. It is made to stringent specifications and used in everything from computers to spacecraft wiring. Now check this out: Electrical conductivity specifications for C11000 ETP copper (99.90% oxygen-free copper) and C10200 (99.99% oxygen-free copper) are IDENTICAL. Now read that last paragraph again. We didn’t say that the electrical conductivity specifications between the two coppers were “close” or “nearly the same” or “in the ballpark.” We said that the electrical conductivity was IDENTICAL. EXACTLY THE SAME CONDUCTIVITY. Quote: Oxygen-free copper is valued more for its chemical purity than its electrical conductivity. OFC is used in plasma deposition (sputtering) processes, including the manufacture of semiconductors and super-conductor components. It’s also the bomb in high-vacuum devices such as particle accelerators. And plenty more similar sources Again, IMHO, It's probably the only time I'd suggest that you go for the quantity (12 Ga and not 16 or 18 Ga !! ) and not the quality (99.95% vs 99.99% purity) P_D . Block settled 07 June 2011 Our little piece of the Interwebs on HomeOne....... viewtopic.php?f=31&t=48577&start=0 A question. Im in Queensland and building a new home. 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