Randy Bey Posted July 25, 2001 Share Posted July 25, 2001 Odd thread, but it has me curious. Some have extolled the virtue of 28 (or even 30) gauge wire, commonly called magnet wire, with the typical ceramic coating, as speaker hookup cable. The resistance of a typical 10' run approaches 4 ohms. This loads the horn drivers, and reduces the efficiency, presumably with the benefit of increasing the driver articulation. The speaker cable of course is vanishingly small. Has anyone tried this setup? For $5 at Rat Shack you can buy enough magnet wire to bi-wire your speakers and have half the roll left over. Quote Link to comment Share on other sites More sharing options...
J Harris Posted July 25, 2001 Share Posted July 25, 2001 I'm going to try this. I saw the post over on Audio Asylum, and have already ordered the magnet wire. Can't hurt to try. Plus the ALK networks on my Cornwalls have lowered my speaker impedance to 4 ohms anyway. J! Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted July 25, 2001 Share Posted July 25, 2001 Randy and J, NO, No! "A thousand times NO!"..... At 4 Ohms impdeance the demands for LOW DC resistance become greater! Do NOT go to such small wire. High resistance AND high series inductance is the result! Al K. Quote Link to comment Share on other sites More sharing options...
WMcD Posted July 25, 2001 Share Posted July 25, 2001 It is a cheap experiment. So there is no reason not try it. OTOH, the series resistance will definitely make a difference to the sound. First, there will be some loss of level. There is also reason to believe there will be boomier bass. This because modern box based bass system design assumes the speaker is fed with a source having a zero, or near zero impedance. Short runs of big gauge wire helps keep that true. However, the resistance of the thin wire will increase the Q. That leads to a peaked bass driver movement at resonance. I remember an article in Speaker Builder, the back page. It was about a lad who gained the unfortunate moniker of "Chrome Dome". This was because his dad forced a radical, short haircut. Not the rage then, as it is now. In any event, the article described a "bass booster switch". All it did was insert an 8 ohm resister in the circuit. Because of lack of damping, the bass was peaky and boomy. Less informed people thought it was an improvement. Edit and PS: If this is a K-Horn, LaScala or Belle, the bass might still boom. One reason for a bit of doubt is that the horn is already contributing to the damping of the driver. So it might not be so pronounced. But at resonance, the amp still should have some effect. Additionally, the series resistance does alter a recognized design parameter for optimum throat size of a horn. PWK cites to a Bell Lab paper for setting throat size based on driver parameters. There is a complicate equation in there. There is a factor of "n" in the equation which takes into account the internal impedance of the driving amplifier. Don Keele used the same equation in a paper which converts the Bell Lab equation into one using T-S parameters. He recognized the "n" and assumes the internal impedance of the amp will be zero. PWK and Delgato uses the Keele equation in the Jubilee design AES paper. The bottom line is that if you add series resistance via wire, the throat size is no longer optimum. Designers of the midrange and tweeter may have made the same assumption. Gil This message has been edited by William F. Gil McDermott on 07-25-2001 at 09:50 PM Quote Link to comment Share on other sites More sharing options...
J Harris Posted July 26, 2001 Share Posted July 26, 2001 Al -- thanks for the headsup. The magnet wire only cost $3.99, so it's not a big deal, and I'll try it anyway when it arrives. At the worst, it'll be an education in the effects of resistance and inductance on the sound. Btw, I'm driving 98dB-efficient speakers with 3.5 watt SET tube amps. Does this make any difference? J! Quote Link to comment Share on other sites More sharing options...
Randy Bey Posted July 26, 2001 Author Share Posted July 26, 2001 Al and Gil, you've convinced me. Not that it would be hard. When I get that feeling that I need to change my speaker cables I think I'll just lie down with a cool compress on my forehead until the feeling goes away. Quote Link to comment Share on other sites More sharing options...
Ray Garrison Posted July 26, 2001 Share Posted July 26, 2001 I tried this with my Epic CF4 before I got the La Scalas. I hated it. Mushy, ill-defined bass, rolled off highs, midrange sounded maybe a bit less forward, though that's not a problem with Epics in the first place... One thing to keep in mind - this stuff is covered with a very, very stubborn enamelled on insulation (don't think it's really ceramic, would be too inflexible). How do you get it off? http://lists.contesting.com/_topband/199802/0122.html http://lists.contesting.com/_topband/199802/0111.html You might want to look at this, also... http://www.alphacore.com/Flatwire.htm and also, but not least, these guys... http://www.eraser.com/browsecat.cgi?mode=open&id=10 ------------------ Music is art Audio is engineering Quote Link to comment Share on other sites More sharing options...
Prana-Bindu Posted July 26, 2001 Share Posted July 26, 2001 Don't forget the invaluable cable stretcher, Ray.... ------------------ May the bridges we burn light our way.... Quote Link to comment Share on other sites More sharing options...
J Harris Posted July 26, 2001 Share Posted July 26, 2001 Ray wrote: "One thing to keep in mind - this stuff is covered with a very, very stubborn enamelled on insulation (don't think it's really ceramic, would be too inflexible). How do you get it off?" Ray, you melt it with a very hot (800-degree) soldering iron. Hold the iron at the tip for a good 15-20 seconds till you see the clear varnish melting and sizzling down the wire to about half an inch. Then tin the tip with solder. Best, J! Quote Link to comment Share on other sites More sharing options...
WMcD Posted July 26, 2001 Share Posted July 26, 2001 I saw a tip years ago that nail polish remover might do it. Maybe that was from the days of rewinding slot car motors. Yeah, that long ago. I don't recall if I tried it. Gil Quote Link to comment Share on other sites More sharing options...
J Harris Posted August 6, 2001 Share Posted August 6, 2001 Okay, I tried it. I removed my fat hose-like Coincident speaker cables (total cost: $800) from my Cornwalls. I took four strands of Radio Shack 30-ga magnet wire, thin as thread, and almost invisible, stripped the ends, and screwed them into the terminals. Didn't even bother to braid them. I can't explain it, but I'm liking the sound. There's LESS bass, not more. There are MORE highs, not less. But the detail is smoother and sweeter than it was before. No longer do I feel I'm being attacked by the tweeter on occasion. It's not perfect, but dammmit, these cables cost $3.99 (and I have yards left over)! Someone's turned me on to a 20.5 ga single-crystal wire from Bottlehead that I'm going to try next. More expensive. It might bring back a little low end. As predicted, I got less volume. But what I get when I turn up the volume is cleaner and sweeter. High series resistance? High inductance? I'm sure that's true. But for whatever reason it sounds better than my old pricey, highly recommended cable. Maybe that cable was problematic and the magnet wire is just halfway to good zip cord. I don't know, I'll try that too. But I don't care what the theory says if the music sounds good. (For now anyway. We'll see how it works with extended listening.) Finally, please note that I'm using this with 3.5 watt single-ended triode tube amps. The original recommendation for this thin stuff was precisely for this configuration: tiny flea-powered SET amps and very efficient horn speakers. Doubtless the garden hose varieties of wire currently being marketed are more appropriate to big high-wattage solid state amps and inefficient direct-radiator speakers. Still exploring... J! P.S. Btw, I'm also using the ALK Cornwall crossover, which put the impedance of the speaker at a nice flat 4 ohms... This message has been edited by J Harris on 08-06-2001 at 09:05 PM Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted August 7, 2001 Share Posted August 7, 2001 J, Listen to the magnet wire for several weeks. I will bet you wind up putting the old cables back! AL K. Quote Link to comment Share on other sites More sharing options...
J Harris Posted August 7, 2001 Share Posted August 7, 2001 Al, We'll see about that!! J! Quote Link to comment Share on other sites More sharing options...
WMcD Posted August 8, 2001 Share Posted August 8, 2001 Thinking about this some more. Heritage series, stock, have a relatively high impedance in the midrange, going up to 30 ohms or so. I think with the direct radiator bass units, Cornwall and Heresy, continue that in the tweeter to some extent. Therefore, perhaps the losses caused by, say 4 ohms is going to cause more loss to the bass in those. On the other hand, Harris has Al K's constant impedance crossovers. So there wouldn't be quite the same effect as with the stock. This is just thinking. Real sound pressure measurements might give us something else, naturally. Gil Quote Link to comment Share on other sites More sharing options...
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