Duke Spinner Posted March 19, 2005 Share Posted March 19, 2005 ... ... ..... Quote Link to comment Share on other sites More sharing options...
John Warren Posted March 19, 2005 Share Posted March 19, 2005 See the spl of an acoustic mass, the complete derivation is on my website. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted March 19, 2005 Share Posted March 19, 2005 John, I am not interested enough to go looking for it. I do not believe it is applicable to this subject! Al K. Quote Link to comment Share on other sites More sharing options...
John Warren Posted March 19, 2005 Share Posted March 19, 2005 ---------------- On 3/19/2005 2:43:51 PM Al Klappenberger wrote: John, I have seen you post this entire quote before. I believe it is out of context jargon that does not apply here. I need YOU to explain how it DOES apply! Who cares about "linear SPL". Define it! Do you mean a flat frequency response? >>For a flat frequnecy response, the SPL is independent of frequency and is equal to P = Ma d2U/dt2 where P is the spl, Ma is the acoustic mass and d2U/dt2 the acceleration of the acoustic mass. This is a fundamental relationship taught in every acoustic engineering course. The acoustic mass is fixed since it's a function of the moving mass and the air load on the radiation area. That leaves the d2U/dt2 term which is the acceleration. Tell me Mr. Klappenburger, if I want a spl that does not vary with frequency what does that tell me about the acceleration??? "Constant acceleration", another SO WHAT? >>This ignores the very fundamental rqmnts for a flat frequency response. In fact, the REASON WHY, the frequency repsonse is NOT ruler flat is that the acceleration of the acoustic mass, in the real world, IS NOT CONSTANT. "Acceleration" means an increase or decrease of speed. A rocket engine burning on a space ship going in a straight like would probably have constant acceleration until the fuel runs out too! Let the loudspeaker driver designers worry about stuff like that. >>You fail to see that the integration of filter theory REQUIRES A FUNDAMENTAL UNDERSTANDING of the interelationship between the acoustic mass, the electrotransduction factor BL and how it is reflected back to the amplifier. You deal with everything from the "microwave" world which, last I looked, has NOTHING whatsover to do with sound reproduction. Al K. ---------------- Quote Link to comment Share on other sites More sharing options...
John Warren Posted March 19, 2005 Share Posted March 19, 2005 ---------------- On 3/19/2005 3:51:10 PM Al Klappenberger wrote: John, I am not interested enough to go looking for it. I do not believe it is applicable to this subject! Al K. ---------------- Christ! I give up. You know what Al, let's just forget it. I'll assume that you will NEVER be able to explain why the "constant impedance" network is an advantage from a SPL vs. frequency perspective and not a "microwave" perspective. Quote Link to comment Share on other sites More sharing options...
John Warren Posted March 19, 2005 Share Posted March 19, 2005 ---------------- On 3/19/2005 2:43:51 PM Al Klappenberger wrote: John, I have seen you post this entire quote before. I believe it is out of context jargon that does not apply here. I need YOU to explain how it DOES apply! Al K. ---------------- >>That force that drives the cone is F = (Bl) E / (Zc + ((Bl)2/Zm)) where: B = flux density in gap l = length of wire in gap Zc = dc resistance of coil and coil inductance Zm = back EMF E = driving voltage What Small is saying is that above resonance (i.e. in the operating range), the force driving the cone is "essentially" a linear function of the driving voltage E. Since the sound pressure is F/Sd (where Sd is the radiation area), the sound pressure then becomes a linear function of the driving voltage. And like I said before, for a fixed sound pressure (i.e. flat fequency response) the only thing that is needed is a constant acceleration. Now it's your turn! Quote Link to comment Share on other sites More sharing options...
JJkizak Posted March 19, 2005 Share Posted March 19, 2005 In heavy communications at RF levels VSWR is eliminated by inserting a 20db pure resistive pad between two units to match impeadance. Of course the signal has to be 20 db above what you need. A nice by product is the RF noise, adverse signals, ghosts, etc. are reduced 20 db also. They have been doing this for years. JJK Quote Link to comment Share on other sites More sharing options...
SilverSport Posted March 19, 2005 Share Posted March 19, 2005 I thought you just plugged 'em in and listened... Bill Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted March 19, 2005 Share Posted March 19, 2005 Warren, You can't argue with somebody who generatees reasoning out of the blue that means nothing! You are the biggest extrapolator I have ever seen! All this is totally without reavance. If I shoot down your B.S. you just come up with more sillyness like your statement months ago that the upper frequency limit of the Khorn woofer was a function of "noise" to spite a direct quote from PWK that it was a function of the complex folding! I suggest that we ignore each other from now on! AL K. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted March 19, 2005 Share Posted March 19, 2005 jjk, Your comment about the 20 db pad brings back memories. I did that once with a filter job. The "return loss" was bad so I stuck in a pad. That improves the return loss by two times the pad loss since returned energy goes through the pad twice. Once forward and then back to the source through the pad again! It was a dirty trick but it met the customers specifications "to the letter"! You could never do that on a loudspeaker though. Al K. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted March 19, 2005 Share Posted March 19, 2005 Guys, I just went back to page 1 of this thread and rewread the initial question. The thread has gone totally off the mark and then totally down the toilet! I will try to answer the original question this way: My idea is the best design I can do with the best parts that I know of where they are needed and the most economical comprmises in areas where they are less important. My background as microwave lumped-component filter desinger since about 1974 or so give me an advantage. The alternative is the Klipsch designs done up with top quality parts. A definite improvement over the same design with 30 year old capacitors. I think the choice is a matter of how much money you want to spend on your hobby. Al K. Quote Link to comment Share on other sites More sharing options...
John Warren Posted March 19, 2005 Share Posted March 19, 2005 ---------------- On 3/18/2005 9:16:04 AM Al Klappenberger wrote: Here's the straight dope. >>dope is the "operative here" I have always said that what I have done is apply microwave techniques to audio. >>and that is a good thing? Why do you do that. Can you explain? Have you "EVER" expalined why you do this???? Here is a page from a book written by Matthaei, Young and Jones titles Microwave Filters, Impedance-matching networks, and Coupling structures. It is the microwave filter designers Bible. >>Folks, the operative here is "microwave". Remember Alk is a "microwave bench tech", not a loudspeaker designer. The optimization criteria for microwave transmission is WAY WAY different than the optimization criteria for a flat frequency reponse from an electrodynamic loudspeaker (remember, constant acceleration of the acoustic mass and so on...) This what I do with ALL my designs. NONE of the Klipsch designs are done this way. >>That proabably should be tellin ya something Al ole boy! As much as you can dispise the garage door guy, he's got some smart folks workin for him. This is why mine are constant impedance. >>And, my question still stands...What's the benefit from a frequency response prespective?? Hmmmmmm? You can't answer that! I will try to translate the techno-babble: >>All the stuff that follows "IS" BS. PERIOD. It has NOTHING TO DO WITH THE AUDIO PREPRODUCTION CHAIN. NOTHING. And you say that "I" extrapolate...... "Diplexer with contiguous pass band" = a device that separates a incoming signal into separate frequency range outputs where one range transitions smoothly into the other with no gaps or glitches. That is, a crossover network. "multiplexer" = many output frequency bands, 2, 3, 4 or more. A "diplexer" is 2 outputs. "Singly loaded prototype" = a lumped component lowpass filter designed to operate from a voltage source (like a power amplifier) into a specific load impedance (like 8 ohms). NOT from 8 Ohms input to 8 Ohms output! These are generally boiled down and tabulated to 1 Ohm impedance and a frequency of 1 radian / second (.159 Hz). My computer program (PCFILT) synthesizes them on demand. "Mapping procedure" = the mathematics used to predict the attenuation at any frequency of a filter scaled from the "prototype" lowpass filter. "Eqs. (16.04.2)" = This is the specific "mapping" formula to determine the 3 dB point on the "prototype" lowpass where BOTH the highpass and lowpass need to be desinged for. Al K. ---------------- BTW, this thread went "down the toliet" because "YOU" decided to put it there. I asked a genuine question, why "constant power" and you go into the rabid cat mode. The problem here is that you cannot answer a direct question that requires a connect between filter theory and electroacoustic affects. You can't, you have no experience with it and refuse to acknowledge it. By your own admission your a filter bench tech. Why does that qualify you as a loudspeaker designer? Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted March 19, 2005 Share Posted March 19, 2005 Guys, It's interesting how some characters just don't know when to quit! Oh yeah, John, When I find out who it is who had been sending you all the harrassing emails you told me about. I will send him my regards. He's right on.. Al K. Quote Link to comment Share on other sites More sharing options...
dodger Posted March 20, 2005 Share Posted March 20, 2005 At the risk of anyone's wrath, the original question did come to state to get not too technical. There are those of us that can chime in with formulas, theories, etc.. But noting even Dean having some problems, this is a topic that was posted in a manner so that the average layman would be able to look at it discern what they may or may not wish to do, or have done. Spats can be decided and argued via PM or email. Though this is the "Technical Questions" Section of the Forum, I don't believe a degree should be necessary to Post, read or reply. I, among others had thought this would be a good way of reading the thought process given to this matter. I posted a question as to whether any thought to whether there was more importance to the upgrading or change of a crossover is more important to one of three Speakers. To answer it myself, as I knew but thought someone would give some credence, it is important in all three due to aging and changing values. But it is important to note the original question, whether a degree is required to read and understand any Posted answers. It is also nice to read Posts where no matter how highly educated one is, there is no condesceding tone. Any answer that is questionable or needs further elaboration can be corrected by the more knowledgable in a manner that all, or most, reading can understand. One can have a Resume or one can have a Curriculum Vitae, though technically they are the same in a Webster's Definition, Courts lean strongly to the term Curriculum Vitae when testifying as an Expert Witness. Some may use Curricula Vitae. Either term is accepted by most Courts. One may also be recognized in several areas depending upon Education, training, Work History and papers or treatises published. The question to ask is why this is being noted. The reasons being not to argue or attempt to persuade others that their point of learning is not quite in tune with the discussion, also as I noted the original post did request to not get too technical. If parts have to get that way, an explanation in short can aid the average reader. I did ask a question that I answered myself - some do wonder whether crossovers need to be upgraded or changed on just a K-Horn or the Belle and the LaScala also. If any wish to elaborate. dodger Quote Link to comment Share on other sites More sharing options...
SilverSport Posted March 20, 2005 Share Posted March 20, 2005 You mean we don't just plug 'em in and listen??? Bill Quote Link to comment Share on other sites More sharing options...
Olorin Posted March 20, 2005 Share Posted March 20, 2005 Well, maybe YOU do, and maybe I do, but some guys have that tinkering instict and just can't help making a good thing better. It helps that they've got the brains to actually FIGURE OUT how to make them better, since heaven knows I'm not the one to carry that ball. God bless 'em, I say. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 20, 2005 Share Posted March 20, 2005 (edited) Retraction. Edited October 28, 2015 by Deang Quote Link to comment Share on other sites More sharing options...
dodger Posted March 20, 2005 Share Posted March 20, 2005 ---------------- On 3/20/2005 2:01:05 AM DeanG wrote: John, you make it sound like Al is building microwave filters for loudspeakers. I don't think the ALK would work real well in the MHz and GHz ranges. I've spent the last hour reading about microwave filters, and I wasn't surprised to find much of the same jargon and math I see in the network design sections of my loudspeaker design books. The applications are obviously different, but I see plenty of corollary. If a loudspeaker designer disected an ALK or ESN without knowing Al or his background -- I don't think they would look at it and say, "WTF is this?". It's apparent that you're seeing it from the motor end (which certainly makes sense), but I don't think you would take kindly to someone dismissing your agruments out of hand because of your background with aircraft engines. I understand you're hot because Al won't specifically address your questions, but they are often cryptic, and it's difficult to see what you're driving at. We need good teachers, but I don't think you can be a good teacher until you put down the ball bat. ---------------- Questions do need to be specific on this Forum or IMO, they are ignored or dismissed. I just posted but it did not carry over to to toady. I appreciate the time you are taking, Dean, in answers and research. I am sure others are also. On the phone with another member earlier the question was posed -"why not send them to Klipsch for updating parts?" It goes beyond the original question, but it does make for a good point for any of you.. dodger Quote Link to comment Share on other sites More sharing options...
dodger Posted March 20, 2005 Share Posted March 20, 2005 ---------------- On 3/20/2005 1:10:55 AM dodger wrote: At the risk of anyone's wrath, the original question did come to state to get not too technical. There are those of us that can chime in with formulas, theories, etc.. But noting even Dean having some problems, this is a topic that was posted in a manner so that the average layman would be able to look at it discern what they may or may not wish to do, or have done. Spats can be decided and argued via PM or email. Though this is the "Technical Questions" Section of the Forum, I don't believe a degree should be necessary to Post, read or reply. I, among others had thought this would be a good way of reading the thought process given to this matter. I posted a question as to whether any thought to whether there was more importance to the upgrading or change of a crossover is more important to one of three Speakers. To answer it myself, as I knew but thought someone would give some credence, it is important in all three due to aging and changing values. But it is important to note the original question, whether a degree is required to read and understand any Posted answers. It is also nice to read Posts where no matter how highly educated one is, there is no condesceding tone. Any answer that is questionable or needs further elaboration can be corrected by the more knowledgable in a manner that all, or most, reading can understand. One can have a Resume or one can have a Curriculum Vitae, though technically they are the same in a Webster's Definition, Courts lean strongly to the term Curriculum Vitae when testifying as an Expert Witness. Some may use Curricula Vitae. Either term is accepted by most Courts. One may also be recognized in several areas depending upon Education, training, Work History and papers or treatises published. The question to ask is why this is being noted. The reasons being not to argue or attempt to persuade others that their point of learning is not quite in tune with the discussion, also as I noted the original post did request to not get too technical. If parts have to get that way, an explanation in short can aid the average reader. I did ask a question that I answered myself - some do wonder whether crossovers need to be upgraded or changed on just a K-Horn or the Belle and the LaScala also. If any wish to elaborate. dodger ---------------- This was the Post referred to. dodger Quote Link to comment Share on other sites More sharing options...
grillecloth Posted March 20, 2005 Share Posted March 20, 2005 Putting that up 1 x woulfda been plenty uless your an expert witness then you gotta tell it 2 maybe 3 times. But you gotta point only 2 stuck with the real deal. The other one thinks hes' teaching. 2 did right. That other one nneeds to learn your being read by everryonee and everybody. Quote Link to comment Share on other sites More sharing options...
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