Members tlbonehead Posted December 22, 2009 Members Share Posted December 22, 2009 You shouldn't do that. As a guitar cable/lead can cause an impedance mismatch because of a potential added capacitance. Or the guitar cable/lead insulation could melt and cause a short. Now using a speaker cable for a guitar cord won't harm your amp or guitar. It just won't sound good because it isn't shielded.exactly! Link to comment Share on other sites More sharing options...
Members Vintage55 Posted December 22, 2009 Members Share Posted December 22, 2009 Higher capacitance is only an issue if an amp is poorly designed... Link to comment Share on other sites More sharing options...
Members tlbonehead Posted December 22, 2009 Members Share Posted December 22, 2009 Higher capacitance is only an issue if an amp is poorly designed...But too much signal thru too small of wire is not a sign of a poorly designed amp. Link to comment Share on other sites More sharing options...
Members Vintage55 Posted December 22, 2009 Members Share Posted December 22, 2009 But too much signal thru too small of wire is not a sign of a poorly designed amp. Not my point. Higher capacitance is only a problem (and would cause the amp to oscillate), if the amp is poorly designed. Small gauge speaker wire is used all the time from amplifiers to speakers. It doesn't sound very good though. But the gauge of the wire is not as important as it's geometry and specific qualities. So many people think high strand 12 gauge is the way to go...not. Too much skin effect with all the surface area that a high strand wire will have. If you want a great sounding speaker wire, go to Home Depot or Lowe's and buy some 6 gauge power wire (specifically, the Southwire brand - 19 conductors, twisted). Rather stiff stuff, but cheap and very, very good. Just don't twist the positive and negative leads together, you'll lose a bit of low end response. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted December 22, 2009 Members Share Posted December 22, 2009 Not my point. Higher capacitance is only a problem (and would cause the amp to oscillate), if the amp is poorly designed. Small gauge speaker wire is used all the time from amplifiers to speakers. It doesn't sound very good though. But the gauge of the wire is not as important as it's geometry and specific qualities. So many people think high strand 12 gauge is the way to go...not. Too much skin effect with all the surface area that a high strand wire will have. If you want a great sounding speaker wire, go to Home Depot or Lowe's and buy some 6 gauge power wire (specifically, the Southwire brand - 19 conductors, twisted). Rather stiff stuff, but cheap and very, very good. Just don't twist the positive and negative leads together, you'll lose a bit of low end response.18 gauge is fine for shorter runs with modest power going thru them. But we are talking about 24 gauge in many instances, along with a shield surrounding it that doesn't allow the heat to escape. Do you have any idea how much less carrying area there is to 24 gauge wire vs 18? Its a huge difference. Link to comment Share on other sites More sharing options...
Members Vintage55 Posted December 22, 2009 Members Share Posted December 22, 2009 Here's a good read for ya...just read the introduction if you want, but you might also want to scroll down to the wire table. While I don't agree with everything stated on this page, the electrical aspects of his article are valid. In case you choose not to follow the link, here's a quote: "Resistance in the speaker circuit is the key factor that determines loudspeaker performance. The loudspeaker circuit includes the connecting wire between the amplifier terminals and the speaker terminals, the amplifier internal impedance and the impedance of the speaker system. There's also contact resistance at the connecting terminals of the amplifier and speaker system. The contact resistance of clean connectors and the internal impedance of good quality amplifiers is normally small. The controlling factors that remain are the speaker system impedance and the speaker wire resistance. The DC resistance of a typical 8-ohm speaker system is about 7 ohms. This resistance is due to the wire in the woofer voice coil. It may be a total shock to some people to know that a typical 8-ohm four layer woofer voice coil contains about 120 feet of number 28 solid copper wire. This wire is all in the circuit with the speaker system hookup wire. It's also much longer than a normal run of hookup wire from the amplifier to the speaker. Even a mid range speaker can have about 30 feet of number 33 solid copper wire and a tweeter can have 20 feet of number 35 solid copper wire." link: http://www.roger-russell.com/wire/wire.htm I absolutely agree with the author that big $ is not needed to get good cables. Link to comment Share on other sites More sharing options...
Members SteinbergerHack Posted December 22, 2009 Members Share Posted December 22, 2009 I'm no expert,but it might shorten the life of your output transformer,because you're making it work harder to push through the cheap wire.think of it like the battery cable on your car,a skinny cable is going to pass less current and will shorten the life of the battery AND the starter motor. Ummm....no. The OP was talking about using a speaker cable for the input. Nothing you do on the input side will hurt the OPT. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted December 22, 2009 Members Share Posted December 22, 2009 good luck. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted December 22, 2009 Members Share Posted December 22, 2009 Ummm....no. The OP was talking about using a speaker cable for the input. Nothing you do on the input side will hurt the OPT. Link to comment Share on other sites More sharing options...
Members Vintage55 Posted December 22, 2009 Members Share Posted December 22, 2009 good luck. ok... Link to comment Share on other sites More sharing options...
Members SteinbergerHack Posted December 22, 2009 Members Share Posted December 22, 2009 And it won't hurt an instrument cable if used as a speaker cable. Sorry, but that makes no sense, at all. It's a signal running through wire. You're not going to overload it, burn it up, melt it, or anything like that. Yes, you can. Lots of cheaper signal cables are made with very small center conductors, which can melt down under high currents - like the output of a 100W amp. Melt down a conductor, and you're looking at either a dead short (bad for any amp) or an open circuit (bad for a tube amp running at high output levels). Link to comment Share on other sites More sharing options...
Members Vintage55 Posted December 22, 2009 Members Share Posted December 22, 2009 Yes, you can. Lots of cheaper signal cables are made with very small center conductors, which can melt down under high currents - like the output of a 100W amp. Melt down a conductor, and you're looking at either a dead short (bad for any amp) or an open circuit (bad for a tube amp running at high output levels). read the info on the pages I gave links to.. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted December 22, 2009 Members Share Posted December 22, 2009 read the info on the pages I gave links to..I swear you are trolling. Link to comment Share on other sites More sharing options...
Members SteinbergerHack Posted December 22, 2009 Members Share Posted December 22, 2009 "Resistance in the speaker circuit is the key factor that determines loudspeaker performance. Not true. Impedance is the key factor, and resistance is only one component of impedance. It is the inductance of the voice coil that actually makes it work; Faraday's law explains this. The more efficient the speaker is, the more electrical energy is being consumed in the inductive portion of the load, while less is being consumed by the resistive portion. You can't compare the load presented by a voice coil (highly reactive, somewhat resistive) with the load presented by a thin coax cable (highly capacitive, highly resistive) - they don't have similar characteristics at all. Link to comment Share on other sites More sharing options...
Members SteinbergerHack Posted December 22, 2009 Members Share Posted December 22, 2009 read the info on the pages I gave links to.. I don't need to read any links to oversimplified treatises to explain Ohm's law and Faraday's laws. Link to comment Share on other sites More sharing options...
Members Vintage55 Posted December 22, 2009 Members Share Posted December 22, 2009 I swear you are trolling. Me? Why would you say that? The subject of the thread was misunderstood and this subject came up. Erroneous statements are being made. Obviously, I'm wasting my time attempting to provide information to those who don't quite understand what's going on in the amp to speaker cable run. You've made up your mind and seem to refuse to look at the data I've provided links to. In a typical short (6ft? max) run from amp head to speaker cab (8-16 ohms), 24 gauge wire is not going to be a factor. Burn up? Right... There would a very minor impedance change presented to the amp with that short of a cable run. Read the data, don't just make statements that you think are true. It seems you might be more the troll, if you want to point fingers. Personally, I hadn't looked at it that way. Is everyone who might disagree with you a troll? Link to comment Share on other sites More sharing options...
Members Vintage55 Posted December 22, 2009 Members Share Posted December 22, 2009 Not true. Impedance is the key factor, and resistance is only one component of impedance.It is the inductance of the voice coil that actually makes it work; Faraday's law explains this. The more efficient the speaker is, the more electrical energy is being consumed in the inductive portion of the load, while less is being consumed by the resistive portion.You can't compare the load presented by a voice coil (highly reactive, somewhat resistive) with the load presented by a thin coax cable (highly capacitive, highly resistive) - they don't have similar characteristics at all. Those aren't my words, but a partial quote of the entire article. If you were to visit the page, inductance and capacitance are also addressed to give the entire picture of the effect of speaker wire from amp to speaker. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted December 22, 2009 Members Share Posted December 22, 2009 Me? Why would you say that? The subject of the thread was misunderstood and this subject came up. Erroneous statements are being made. Obviously, I'm wasting my time attempting to provide information to those who don't quite understand what's going on in the amp to speaker cable run. You've made up your mind and seem to refuse to look at the data I've provided links to. In a typical short (6ft? max) run from amp head to speaker cab (8-16 ohms), 24 gauge wire is not going to be a factor. Burn up? Right...There would a very minor impedance change presented to the amp with that short of a cable run. Read the data, don't just make statements that you think are true.It seems you might be more the troll, if you want to point fingers. Personally, I hadn't looked at it that way. Is everyone who might disagree with you a troll?I just find this info very careless, especially when people's equipment is at risk. I guess if you want to risk your own stuff, fine. But hopefully others will not follow suit. And I believe I am ok as far as understanding what is going on both in a speaker's VC windings, and in a basic amp > speaker lead. Link to comment Share on other sites More sharing options...
Members Mr_GoodBomb Posted December 22, 2009 Author Members Share Posted December 22, 2009 Is everyone who might disagree with you a troll? In his eyes? Yes. Link to comment Share on other sites More sharing options...
Members Vintage55 Posted December 22, 2009 Members Share Posted December 22, 2009 I just find this info very careless, especially when people's equipment is at risk. I guess if you want to risk your own stuff, fine. But hopefully others will not follow suit. And I believe I am ok as far as understanding what is going on both in a speaker's VC windings, and in a basic amp > speaker lead. Not sure why you see this info as careless, when it is repeated from a number of sources available, if one chooses to search it out. I'm not saying you should use 24 gauge speaker wire, far from it...I recommended a cheap 6 gauge that works extremely well as a speaker cable. I'm just saying that doing so, for a short head to cab run will not do any harm. Resistance, capacitance and inductance for a short run would have negligable effects on performance and do no harm to the amp, unless the somewhat higher impedance of a coax cable is used with a poorly designed amp. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted December 22, 2009 Members Share Posted December 22, 2009 Not sure why you see this info as careless, when it is repeated from a number of sources available, if one chooses to search it out. I'm not saying you should use 24 gauge speaker wire, far from it...I recommended a cheap 6 gauge that works extremely well as a speaker cable. I'm just saying that doing so, for a short head to cab run will not do any harm. Resistance, capacitance and inductance for a short run would have negligable effects on performance and do no harm to the amp, unless the somewhat higher impedance of a coax cable is used with a poorly designed amp.No one in their right mind would try and use 6 gauge cable for speakers. There's no way you could even solder it to your connections. In fact, impossible to solder and fit under the cover. Link to comment Share on other sites More sharing options...
Members Vintage55 Posted December 22, 2009 Members Share Posted December 22, 2009 No one in their right mind would try and use 6 gauge cable for speakers. There's no way you could even solder it to your connections. In fact, impossible to solder and fit under the cover. Geeze....you just like to argue.... I use that stuff for home speakers, with spade lugs crimped on. Of course you can't fit 6 gauge into a phone plug. Get some of the same stuff in a smaller gauge that will fit... Link to comment Share on other sites More sharing options...
Members tlbonehead Posted December 22, 2009 Members Share Posted December 22, 2009 Geeze....you just like to argue....I use that stuff for home speakers, with spade lugs crimped on. Of course you can't fit 6 gauge into a phone plug. Get some of the same stuff in a smaller gauge that will fit...Well it certainly seemed like you were suggesting it for speaker cables since that was the subject and you really didn't state otherwise. Had me wondering. NTL, it is severe overkill, although it will certainly work. 16 gauge should be good for about 400-500 watts up to 30' or so. Link to comment Share on other sites More sharing options...
Members SteinbergerHack Posted December 28, 2009 Members Share Posted December 28, 2009 16 gauge should be good for about 400-500 watts up to 30' or so. I generally try to use 12 or 14 ga for anything over 100 Watts. Is it theoretically necessary? Not in most cases, but it will safely handle whatever it may get used for in a pinch - even a very low impedance load (2 Ohms) at very high power. Bottom line: I try to use heavy enough cable to cover ANY use that I may need to cover. That way, I don't ever have to worry about someone using the "wrong" cable - anything in the bin will be OK. I use the same principle in my race car spares; the only bolts I keep around are AN or better - no Grade 8 or Grade 5 junk that might get substituted into a critical application by mistake. Link to comment Share on other sites More sharing options...
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