On 10/28/2010 2:21 PM, Don Wilhelm wrote: > Yes, it is all about Ohm's law, but there *are* some advantages to the > "exotic" cables 1) they are usually made with large diameter wires, > satisfying the Ohm's law requirement even with higher power amplifiers; > and 2) they are quite flexible which makes running them in tight places > easier, and they will stand more flexing before the wires break.
Sure. But those large diameter wires that are part of exotic cables also come with a huge markup, justified only by the marketing gobledegook. These mechanical issues are their only advantage, but sometimes that's important. Good engineers view them as simply another alternative, taking their cost into account. There are, for example, some very wide flat two-conductor cables, sort of like flex circuit packs, that are built so that they can be run under carpet. They would NOT be good from an RFI point of view though, because they're not twisted. :) #12 stranded copper is $0.10/ft in 500 ft lengths at your friendly Home Depot. Probably less than double that in 50 ft lengths. Even paired house wire or flexible AC extension cords are a jacket is a good cheap alternative. You can also reduce the resistance by putting the green wire (ground) in parallel with one of the other conductors. Just be sure to cut off the AC connectors -- some rather smoke could be released from speakers or amplifiers if someone plugged that cable into a 120V outlet by mistake. :) Funny story, sort of. About 15 years ago, some fool bought a booth at an AES convention to promote a product he called J-Conn or something like that. The product was simply a set of adapters to convert from AC plugs and sockets to speaker connectors. Throughout the convention, many engineers descended upon their booth to tell them how stupid and dangerous that was. > Other than for those advantages, any piece of wire of a suitable size > for the max power involved will do the job The issue is NOT power, but rather damping factor. If the resistance is high, the transient response of the loudspeaker can be degraded, so the low end sounds sloppy. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
