Deang Posted June 21, 2003 Share Posted June 21, 2003 I need the brains of the outfit to help me out here. http://www.audioasylum.com/audio/tweaks/messages/84878.html Quote Link to comment Share on other sites More sharing options...
bkrop Posted June 21, 2003 Share Posted June 21, 2003 Way over my paygrade! Quote Link to comment Share on other sites More sharing options...
NOSValves Posted June 21, 2003 Share Posted June 21, 2003 Ithought you were going to start trouble Quote Link to comment Share on other sites More sharing options...
Deang Posted June 21, 2003 Author Share Posted June 21, 2003 Looks like I did -- check out the thread at the asylum. Looks like I'm going to take a beating. Quote Link to comment Share on other sites More sharing options...
leok Posted June 22, 2003 Share Posted June 22, 2003 Dean, You could always put a 0.5 Ohm resistor in series with the new inductor and see if that helps. leok Quote Link to comment Share on other sites More sharing options...
Deang Posted June 22, 2003 Author Share Posted June 22, 2003 Yes, I know that would fix it. It begs the question though doesn't it? If a resistor should go in to bring the DCR back to where it needs to be to create the proper relationship between the drivers, cabinet, and port length -- then what was the point in changing the inductor in the first place? What real benefit is derived from using a 14AWG or bigger inductor? I have almost decided the most sensical thing to do is treat this inductor as being part of a balanced system -- and find a suitable air core replacement that matches in mH as well as DCR. It won't look as cool on the board -- but at least it will be "right". Quote Link to comment Share on other sites More sharing options...
John Warren Posted June 22, 2003 Share Posted June 22, 2003 Swapping out inductors in vented/sealed systems can be tricky. I'm quite sure that the folks at Klipsch have adjusted the alignment of the system with the inductor loss factored in. The electrical Q of the woofer can be *tweeked* with inductor resistance to optimize it for the enclosure. In this case, a junk inductor might be the best engineering solution. Sounds like you might have upset the apple cart going to the lower DC resistance. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 22, 2003 Author Share Posted June 22, 2003 "... a junk inductor might be the best engineering solution." I believe this might be true. "The electrical Q of the woofer can be *tweeked* with inductor resistance to optimize it for the enclosure." Is adding a resistor in series with an inductor really the same as "inductor resistance"? My multimeter says so, but I've seen posts over at the Asylum that indicate it's not the same. I did put a 1 ohm resistor on my capacitance meter and it showed .05uF of capacitance -- which surprised me. I figured it would have some -- but much more than I would have thought. So -- junk inductor back in, or add the resistor? Let's see your votes. Yeesh, this is getting really pathetic. Quote Link to comment Share on other sites More sharing options...
John Warren Posted June 22, 2003 Share Posted June 22, 2003 ---------------- On 6/22/2003 12:27:40 PM DeanG wrote: then what was the point in changing the inductor in the first place? What real benefit is derived from using a 14AWG or bigger inductor? ---------------- If the original inductor was an iron or steel laminate a change to air core could be a benefit but that depends on the power driven into the choke and if the core is driven into saturation or no. The real benefit is for the manufacturer, if they are clever (and Klipsch is very clever) and they know all the system parameters, they can use a cheap inductor but align the enclosure to still get a good response. Based on Small, series resistance raises Qec of the driver as follows- Re + Rg Qec' = Qec --------- Re for a perfect network Rg = 0 and then Qec' = Qec. Re is voice coil resistance and dominates the expression. Recall that the total system Qts is both this and mechanical Qmc. Inductor DC resistance has an effect of Rg. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 22, 2003 Author Share Posted June 22, 2003 Qec and Qmc are for sealed systems, so I guess I can just insert Qes and Qms for vented alignments into your little formula? Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted June 22, 2003 Share Posted June 22, 2003 It may be out of print now, but check out a copy of that book "The Tweakers Bible" which contains charts translating the values of electronic components directly to audio implications. I particularly like the series of charts which directly convert color code (on resistors and capacitors etc.) directly to audio (sonic) results. There is a chart for almost every brand. This color code chart is handy because it eliminates the need to even know what those complicated electronic terms are. You just go from say red, yellow, brown, violet, etc. directly to things like "soul", "thwack" "whack", "thud" and "slam" without bothering with confusing farads, mhos, henrys, and volts etc. I found my copy in a night table drawer at a motel in Weed California. Another nice feature is how they translate the mathematical formulae into little fairy tale like stories and visualizations which even a kid can understand. Not only can you solve complicated electronic conundrums but you will have sweet dreams of electrons dancing through a colorful labyrinth of tunnels, back roads, freeways, lonely one way streets, and a variety of scarry carnival rides. There is an animated film in the works and it will probably revolutionize electronic engineering. Generally you cannot go wrong if you maximize "green" in your circuit. C&S Quote Link to comment Share on other sites More sharing options...
Deang Posted June 22, 2003 Author Share Posted June 22, 2003 LOL -- that's rich. What else should one expect to find in a place called 'Weed'. Quote Link to comment Share on other sites More sharing options...
leok Posted June 22, 2003 Share Posted June 22, 2003 Dean, I don't "know" that the resistor would fix it, I just mentioned it as something easy that cloud be tried. I do think that an air core inductor is an improvement over a ferrite core device. My reasoning is that the ferrite has repolarization losses as the current crosses from one direction to the other (more crossover distortion) that would distort low level detail and harmonic information. With that in mind, a good air core w/ resistor would be an improvement over a ferrite core device. leok Quote Link to comment Share on other sites More sharing options...
Terry N. Cruse Posted June 22, 2003 Share Posted June 22, 2003 ---------------- On 6/22/2003 4:02:10 PM DeanG wrote: LOL -- that's rich. What else should one expect to find in a place called 'Weed'. ---------------- Dean,was that place called Whacked CA.? I think that I was there in 1969 but its difficult to remember. Surfs up. C&S has acknowledged "slam". Cool. Quote Link to comment Share on other sites More sharing options...
Malcolm Posted June 22, 2003 Share Posted June 22, 2003 An air core inductor with a resistor will not have the same loss as an iron core inductor with the same DCR. The reason is that loss due to resistance, sometimes called copper loss, is not the only loss in an iron core inductor. There are other losses due to eddy currents and hysteresis. Is going by the DCR of the original inductor good enough? IMHO probably. The designer probably took the DCR of the inductor into account when balancing the woofer, squakwer driver and tweeter. OTOH I'll be he just considered the other losses minor technicalities that did not have to be dealt with in a simple audio circuit. IMHO the reason for going with an air core inductor have nothing to do with DCR and losses. The reason is to eliminate the signal distortion that eddy currents and hysteresis in the inductor cause. Just be aware, though, that these are minor compare to the distortion that the woofer itself introduces. You may or may not hear a difference. Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted June 22, 2003 Share Posted June 22, 2003 What else should one expect to find in a place called Weed C&S Quote Link to comment Share on other sites More sharing options...
Deang Posted June 22, 2003 Author Share Posted June 22, 2003 A very nice place as far as places on the planet go. O'le Abner Weed did us a good one. Quote Link to comment Share on other sites More sharing options...
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