mustang guy Posted April 27, 2014 Author Share Posted April 27, 2014 (edited) Good info. I suppose for the sake of the schematic above, having the resistance value is unimportant. It is what it is, and if somebody wanted to tweak the network, I am sure they would take resistance measurements as one of the first measures of business. I will simply leave it as an RDE050, and define it as a polyswitch in the schematic. When I started this thread, I thought it was a 5pF ceramic cap being used as part of an RC filter. Edited April 27, 2014 by mustang guy Quote Link to comment Share on other sites More sharing options...
Deang Posted April 27, 2014 Share Posted April 27, 2014 The first time I saw one I had no idea what it was. I didn't know Bob very well back then and called Trey, who couldn't even figure out what I was trying to describe. That was 10 years ago. I recently hired John Warren to take some acoustic measurements of a couple of network modifications to help me better understand what the mods were doing. I now need to hire him to explain the results to me. He just posted some results showing the impact on phase from using an autotransformer and associated/various taps. I've been curious about this ever since Roy mentioned it in Hope five years ago. I think the results are interesting, but I have a lot of questions - and as soon as I figure out what words I want to use to ask them, I will! There's no end to the questions, which only spawn more questions. The resistance of a polyswitch seems like such a trivial, insignificant thing. But I'm no longer sure if "trivial" or "insignificant" can be rightly applied to anything in this crazy thing we call "a hobby". There is a big difference between a half ohm and a full ohm of resistance when it is in series with the driver. During a rebuild, they should probably be replaced, and according to Bob, especially if they are one of the Kg loudspeakers or from the Pro/Cinema line. Quote Link to comment Share on other sites More sharing options...
djk Posted April 28, 2014 Share Posted April 28, 2014 1.17Ω is the post-trip resistance (after it has tripped one time). If it has never tripped it will be about 0.5Ω. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted April 28, 2014 Author Share Posted April 28, 2014 Aha! You are right, and it is right there in the spec sheet. The initial resistance is 0.50 - 0.77Ω at 20° C. At one hour post normal trip, the MAX resistance is 1.17Ω Quote Link to comment Share on other sites More sharing options...
JohnA Posted April 30, 2014 Share Posted April 30, 2014 MG, You labeled your schematic Type KP-2.0a. That indicates a revision level above KP-2.0. This could account for the change in tweeter phase. You'll note on the Coulter supplied schematic that the last rev changed the KLiP resistor from 180 ohms to 200 ohms and that was altered by hand to 100 on the schematic. I'd say you have an even later rev. You can experiment with the tweeter phase, but I expect the best response comes from the OEM configuration. Hi Gil! Quote Link to comment Share on other sites More sharing options...
WMcD Posted April 30, 2014 Share Posted April 30, 2014 Hi John, Good to see you posting. Wm Gil McD Quote Link to comment Share on other sites More sharing options...
mustang guy Posted May 1, 2014 Author Share Posted May 1, 2014 Good catch John. That makes perfect sense. Quote Link to comment Share on other sites More sharing options...
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