Deang Posted February 24, 2019 Share Posted February 24, 2019 People think all of the voodoo is with the high priced stuff, but that’s not always true - sometimes the cheap stuff is worse. What do we ideally want? 1. Film and tin foil (not metalized) 2. Fully protected 3. Soldered leads 4. Damping (oil or wax) And yeah, it’s audible. You want something to outlive you and deliver the best performance possible, it’s going to cost you a bit. The inside/outside foil connection is marked on all of the parts I use - but it means nothing on a filter for loudspeakers. This whole wire gauge/ wire length thing is some of the stupidest shit I’ve ever read - which is why I decided to hijack/salvage the thread. 3 Quote Link to comment Share on other sites More sharing options...
CoolCanuck Posted February 25, 2019 Share Posted February 25, 2019 (edited) OK, I have to redo the caps in Heresy1 now. Just ended up working on my old cars starter system. Is it OK to use the old 4/0 here? Guess I'll have to mod the terminal strip though... To my untrained eye & ears, should have low losses, no? Edited February 25, 2019 by CoolCanuck Quote Link to comment Share on other sites More sharing options...
karlson3 Posted February 25, 2019 Share Posted February 25, 2019 I once saw cable almost that thick between a D76 ARC and Magnepan MGII. For less loss in the inductor - here's a $27 Hammond part rated for 10A max DC. (Jeff Medwin some time ago reminded me that the inductance rating is under load so it might be unwound a bit to measure like a Klipsch 2.5mH inductor. I had a part similar to PWK's unit made at Ultra Print - interestingly , the core had no gap. Its possible in some systems to have too low DCR on the inductor, and that can sound "lean" or even "steely" with overdamped bass. https://www.mouser.com/ProductDetail/Hammond-Manufacturing/159ZL?qs=sGAEpiMZZMsg%2By3WlYCkU%2BF2lzLeRQXMPOiqo2ZXmaA%3D Quote Link to comment Share on other sites More sharing options...
glens Posted February 25, 2019 Share Posted February 25, 2019 7 hours ago, karlson3 said: (Jeff Medwin some time ago reminded me that the inductance rating is under load so it might be unwound a bit to measure like a Klipsch 2.5mH inductor. That would make sense if inductance drops appreciably under load so there's more than needed when lightly loaded. I'd like to see some documentation on that one. My initial thought is that inductance would only drop upon saturation. It could be argued to merely use devices more appropriate to the task at hand... Quote Its possible in some systems to have too low DCR on the inductor, and that can sound "lean" or even "steely" with overdamped bass. I've seen recommendation to add an ohm or two in series to muddy-up the bass a bit. Am thinking it was in relation to SETs, but not sure; except am pretty sure it was when using an output transformer at least (i.e. a tube amp). Quote Link to comment Share on other sites More sharing options...
karlson3 Posted February 25, 2019 Share Posted February 25, 2019 I've often use cheap solid state (non "audiophile") amplifiers with low output impedance so say an Erse steel core lowpass inductor could in some instances sound overdamped - perhaps adding a half ohm series resistance to the inductor in those cases could restore a sense of balance and ease. ElectroCube talking about the termination of foil vs metallized film caps Quote Link to comment Share on other sites More sharing options...
glens Posted February 25, 2019 Share Posted February 25, 2019 So, like Dean says, distinct layers of foil and film are preferred over "metalized" film (like for candy bar wrappers). Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 25, 2019 Share Posted February 25, 2019 17 hours ago, Deang said: This whole wire gauge/ wire length thing is some of the stupidest shit I’ve ever read - which is why I decided to hijack/salvage the thread. Psychosomatic delusion of hyper acute hearing would be a more accurate term. As if having wire fit to jump start a LOCOmotive when carrying MILLIamps of current would make any audible difference. Besides, in comparison to the rest of the electromagnetic spectrum, Audio is like Direct Current (in other words, VERY SLOW). Loco inceed. Like PWK thought it was a waste of good copper when he once told me: "Why use 8 AWG wire to drive a 30 AWG wire in a woofer voice coil, except as a marketing decision, not an engineering one." Quote Link to comment Share on other sites More sharing options...
Alexander Posted February 25, 2019 Share Posted February 25, 2019 Is this Jeffery guy for real? He must be just trying to ruffle board members feathers Quote Link to comment Share on other sites More sharing options...
Alexander Posted February 25, 2019 Share Posted February 25, 2019 2 minutes ago, Jeffrey D. Medwin said: Claude: Mr. PWK told you the wrong answer, because he was referring to steady state signals, like a sine wave, . He was TOTALLY not thinking at all about INSTANTANEOUS PEAKS, AND DYNAMIC CONTRASTING which occurs all the time in music . This is so obvious. Jeff Medwin Yea, clearly PWK had no idea how speakers and crossover work! Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted February 25, 2019 Share Posted February 25, 2019 42 minutes ago, Jeffrey D. Medwin said: THINK OF A CORVETTE WITH A GAS LINE THAT IS 1/100TH OF AN INCH IN INSIDE DIAMETER. Think of a Corvette with a fuel line that's 3" in diameter. There's a point where increasing the size of something works no better than an item that supplies the proper amount of flow to what it's supplying. 44 minutes ago, Jeffrey D. Medwin said: This is so obvious. 3 Quote Link to comment Share on other sites More sharing options...
billybob Posted February 25, 2019 Share Posted February 25, 2019 Need electric fuel pump with 150 lbs. of pressure to force feed the thing or, need a bigger intake to begin with. 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted February 25, 2019 Share Posted February 25, 2019 2 minutes ago, Jeffrey D. Medwin said: WE got all that,.......................but the fuel line from the gas tank to the Corvette motor is 1/100th of an inch !.D. Jeff Improvise...I know my audio, I mean auto... 1 Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 25, 2019 Share Posted February 25, 2019 1 hour ago, Jeffrey D. Medwin said: Claude: Mr. PWK told you the wrong answer, because he was referring and thinking about steady state signals, like a sine wave, . He was TOTALLY not thinking at all about INSTANTANEOUS PEAKS, AND DYNAMIC CONTRASTING which occurs all the time in music . We have no control; of the 30 AWG wire in the voice coil. It is fixed, but we do have control of how to get the energy TO that voice coil wire !! . WE do have control , design control, in the wiring feeding it. The woofer voice coil will be driven far far far better, with 8 AWG wiring having SILVER content, amp-to-crossover, crossover's internal parts, , crossover -to-woofer's voice coil. THINK OF A CORVETTE WITH A GAS LINE THAT IS 1/100TH OF AN INCH IN INSIDE DIAMETER. This is so obvious. Jeff Medwin PWK also told me that 17 db headroom was all that was needed beyond a nominal "normal volume" for a symphony orchestra's dynamics, which represents the GREATEST dynamic range one is likely to encounter in live music reproduction. I just round up his figure to 20 db, which is easier to deal with. He based his reasoning on 20 Megahertz oscilloscopes, Spectrum Analysers, and hundreds of his Spaced Omni Microphone recordings, several of which I heard myself in his home. His instruments, experience, my instruments, my ears, and my experience take precedence over what you present here. At a normal, industry standard, nominal Sound Pressure of 83 dbA at my sweet spot only requires about 50-100 MilliWatts of power per speaker, with about 1 watt on my Horn subwoofers for listening to music, up to 100 watts to simulate a Plane Crash in the Movie "Flight of the Phoenix." In my past experience with Khorns playing at "stupid loud levels" exceeding 95 dbA, I experienced 10-20 Watt PEAKS, worst case, per channel. So even if we go crazy with the headroom of 30 db, or 1000X the power requiement for peaks, it is easily done with a 50-100 watt amplifier per channel. The most power required in the Woofer section (wehre all the power is NEEDED) is a 5 Amp/20 volt PEAK for that Ridiculous 30 db of headroom. Although it can't hurt to use as much copper 8 AWG, as you suggest, in a crossover, the maximum VOLTAGE or CURRENT that can be handled with 18 AWG wire far exceeds these requirements. It's also difficult to solder such a "heatsink" of copper. I also used to be a Printed Circuit board designer for various electrnonics, including 6 Megawatt Wind Generators, FYI. So when it comes to trusting the SCIENCE vs. you hearing and OPINIONS, misguided or not, I trust the science and as preached by PWK, every time. You proposed stuff would not survive an AB/X test, methinks. Either way, it's all opinions, so just Enjoy your music. 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted February 25, 2019 Share Posted February 25, 2019 8 minutes ago, Jeffrey D. Medwin said: we both independently arrived at 8 AWG 2 people with similar OPINIONS vs countless others with science to back them up. The flat earth society has a lot more members than that and I don't believe them either. I'll let others respond as we're clearly on different wave lengths. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 25, 2019 Share Posted February 25, 2019 2 minutes ago, Jeffrey D. Medwin said: Sir, Your audio mentor used a 20 Meg scope, to study audio, and my mentor in the 1980s actually used a 2 Gig scope, to study audio. I come to this from a different background than you !! My mentor was manufacturing seven way speakers in the 1980s that measured plus and minus 2 dB, 12 hZ to 110 khZ. You never knew that, did you ?? Jeff Medwin Just label me ignorant and apathetic. I didn't know and I didn't care. Although I do admire your tenacity of opinion in this matter. 1 Quote Link to comment Share on other sites More sharing options...
glens Posted February 25, 2019 Share Posted February 25, 2019 I think I can "see" where Jeff is coming from (not that I concur entirely). You can be listening at a level of milliamps average level but a sudden transient would, for the instant, increase the level at a rate that, were it sustained, be amps, yet no so long as to raise the overall average appreciably. And if there weren't a sufficient reservoir of electrons under pressure in the leads (like fuel in the line feeding the Corvette engine), the pressure might fall too far before the transient can be properly delivered, and the speaker would run lean on the peaks. Does that about sum it up, Jeff? Quote Link to comment Share on other sites More sharing options...
billybob Posted February 25, 2019 Share Posted February 25, 2019 Well surely, I am the go to person here. Anyone can tell you, the oldtimer can, that my mailbox stays full, just ask me a question. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 25, 2019 Share Posted February 25, 2019 32 minutes ago, glens said: I think I can "see" where Jeff is coming from (not that I concur entirely). You can be listening at a level of milliamps average level but a sudden transient would, for the instant, increase the level at a rate that, were it sustained, be amps, yet no so long as to raise the overall average appreciably. And if there weren't a sufficient reservoir of electrons under pressure in the leads (like fuel in the line feeding the Corvette engine), the pressure might fall too far before the transient can be properly delivered, and the speaker would run lean on the peaks. Does that about sum it up, Jeff? Go read my math, which still refutes the claim, even with my +10 db "stupid loud" exaggeration. Quote Link to comment Share on other sites More sharing options...
DizRotus Posted February 25, 2019 Share Posted February 25, 2019 Arguing about wire is akin to arguing about religion. It’s pointless. 3 Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 25, 2019 Share Posted February 25, 2019 4 minutes ago, Jeffrey D. Medwin said: I care !! All my life, I wanted to have a realistic-sounding home hi fidelity system. Jeff I have that all my life, ever since I got into big horns at 19. I was just apathetic about having 110 Khz tweeters when my hearing has gone from 17 Khz. down to 12 Khz. recently. The SST was a fine aircraft for intercontinental travel, but it made a poor commuter vehicle. Waste of time and money. I too like low power amplifiers, like the First Watt varieties. Quote Link to comment Share on other sites More sharing options...
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