djk Posted September 19, 2014 Share Posted September 19, 2014 " And just how would you know that?" Uh, I have eyes? (love your user name!) "Does that mean it is for use below 500Hz only?" Frequency Response 500hz Minimum Recommended Crossover Point It should be obvious it's not big enough to run below 500hz. I'd like to hear this one from Autotech. Frequency Response 450hz Minimum Recommended Crossover Point The smaller one is half the price and Frequency Response 800hz Minimum Recommended Crossover Point "which you have mentioned beofre could be heard" It's not the CD part that is the problem, it's the pinch and the slot. The newer JBL designs are CD without the pinch and the slot. JBL 4622 cinema system. The horn is the 2384 (with a 1.5" throat, also available in 1-3/8 18 for a 1" driver). This horn has no flat inner surfaces and the inside corners are rounded out, it sounds utterly natural. 1 Quote Link to comment Share on other sites More sharing options...
Chris A Posted September 19, 2014 Share Posted September 19, 2014 On 9/16/2014 at 9:26 PM, duder1982 said: I didn't want to crash the threads with Roy's interviews, so I started a new one. But why not a round tractrix horn, I know it could be opinion but I have read that a lot of folks like the sound better then square. Is it the fact its harder to make, maybe 3d printing will change that. Just curious on your thoughts. From diyAudio: Quote Q: "is anybody kind enough to explain me what is 'on-axis null' when talking about a horn?" A: "All wave fronts diffract from the mouth edge of a horn to a certain extent. The more abrupt this termination the more diffraction there is. Now, if the mouth of the horn is round then at some frequency and far field location the diffracted waves will be uniformly 180 degrees out of phase from the direct wave. This will cause cancellation. A round horn will be the worst case, followed by an elliptical one because for the circular mouth the distance to the axis are all the same. You will almost never see this effect in a square mouth horn because the path lengths all differ. The width and depth of the cancellation depends on many factors that are far too complex to get into in a forum post. Also, the wave front arriving at the mouth must be fairly coherent, [otherwise] the diffraction won't be coherent and the null will be diminished. Hence you will not tend to see this effect on any horn which has internal diffraction [such as those profiles having a diffraction slot inside the horn]. they will have numerous peaks and dips and one could not really say what is an axial cancellation and what isn't." Quote Link to comment Share on other sites More sharing options...
Klipsch Employees Chief bonehead Posted September 20, 2014 Klipsch Employees Share Posted September 20, 2014 " And just how would you know that?" Uh, I have eyes? (love your user name!) .[/quote Sometimes the eyes can deceive. Straight sided walls do not a conical make. Sorry. You are wrong. Quote Link to comment Share on other sites More sharing options...
Chris A Posted September 20, 2014 Share Posted September 20, 2014 The only person that I know would mention that...is... Quote Link to comment Share on other sites More sharing options...
Dr Morbius Posted September 20, 2014 Share Posted September 20, 2014 "Who are you going to believe, me or your own eyes?" - Chico Marx in "Duck Soup" a fav movie of mine. 1 Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted September 20, 2014 Share Posted September 20, 2014 " And just how would you know that?" Uh, I have eyes? (love your user name!) .[/quote Sometimes the eyes can deceive. Straight sided walls do not a conical make. Sorry. You are wrong. Look harder...squint if you have to. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted September 21, 2014 Share Posted September 21, 2014 (edited) " And just how would you know that?" Uh, I have eyes? (love your user name!) .[/quote Sometimes the eyes can deceive. Straight sided walls do not a conical make. Sorry. You are wrong. Look harder...squint if you have to. He's giving us the answer..... straight walls in itself doesn't mean you have a conical horn expansion. miketn Edited September 21, 2014 by mikebse2a3 Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted September 22, 2014 Share Posted September 22, 2014 " And just how would you know that?" Uh, I have eyes? (love your user name!) .[/quote Sometimes the eyes can deceive. Straight sided walls do not a conical make. Sorry. You are wrong. Look harder...squint if you have to. He's giving us the answer..... straight walls in itself doesn't mean you have a conical horn expansion. miketn My mistake. From reading the post above it seemed to refer to the 500 hz cutoff. Quote Link to comment Share on other sites More sharing options...
djk Posted September 23, 2014 Share Posted September 23, 2014 "straight walls in itself doesn't mean you have a conical horn expansion." Really, what kind of expansion is it then? Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted September 23, 2014 Share Posted September 23, 2014 (edited) "straight walls in itself doesn't mean you have a conical horn expansion." Really, what kind of expansion is it then? modified tractrixDo all horns with straight sides follow the conical expansion? Edited September 23, 2014 by mikebse2a3 Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted September 23, 2014 Share Posted September 23, 2014 "straight walls in itself doesn't mean you have a conical horn expansion." Really, what kind of expansion is it then? modified tractrixDo all horns with straight sides follow the conical expansion? Probably not. 60% circular is what Danley describes in his white paper as conical, although I have a narrower one called a "megaphone" that I bought on Ebay cheap. The MWM woofer has straight sides but has an expansion that approximates something other than a conical epansion. But since midrange is the discussion here, I have seen more varieties there and in tweeters than shown here. It's a big world out there. Blow your own bubbles. Quote Link to comment Share on other sites More sharing options...
DrWho Posted September 23, 2014 Share Posted September 23, 2014 (edited) "straight walls in itself doesn't mean you have a conical horn expansion." Really, what kind of expansion is it then? I'm with you Dennis - there is a ton of literature referring to straight-wall horns as conical. I know that it is scientifically incorrect, but who cares? This all comes down to semantics. A conical horn can only be a circular cross-section with any throat angle as that is the 1P solution to the wave equation. Changing the shape of the cross-section changes the solution in a way that has not yet been solved analytically. So if you want to be nit-picky, a straight-walled 90x60 rectangular cross-section horn is not a "conical horn" because it doesn't have the acoustical loading properties of the conical 1P solution to the wave equation. There are two ironic things about this: 1) The 1P solution that defines the conical horn makes some invalid assumptions about how waves propagate through it. 2) The K402 doesn't follow the tractrix equation either (which also makes equally invalid assumptions) At the end of the day, the "equation of the horn" is not an audible parameter so I could care less which equation was butchered to provide a repeatable engineering solution. I will ask this question though.....has anyone shown that a rectangular cross-section horn doesn't satisfy the same conical horn assumptions with a 2P solution? I think we would all agree that a 2P solution is more accurate than a 1P solution - and I'd argue that such a horn would indeed more accurately be described as conical. I started crunching through the math and I think the straight-walled rectangular horn comes close to being conical from an assumption perspective. It gets complicated because the wavefront gets squished in weird ways so there may be some extra constraints required... Anyways, the point is that you can't apply the 1P assumptions to a horn design that is inherently 2P by design. Edited September 23, 2014 by DrWho Quote Link to comment Share on other sites More sharing options...
Klipsch Employees Chief bonehead Posted September 23, 2014 Klipsch Employees Share Posted September 23, 2014 They call it the conical equation for a reason. Come on doc! Nit picky? Pay attention to the 20%.......... Quote Link to comment Share on other sites More sharing options...
Klipsch Employees Chief bonehead Posted September 23, 2014 Klipsch Employees Share Posted September 23, 2014 Use all the Ps you want. If the area expansion is not following the equation then you can call it anything you now can't you? It does matter how you slice it. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted September 23, 2014 Share Posted September 23, 2014 I would say that a straight sided horn possessing a variable taper rate is a conical horn. A horn so designed will have a transmission coefficient that is attributed to a conical horn. It will have no characteristic cutoff frequency, like a conical horn. If it walks like a duck, quacks like a duck, and looks like a duck... Quote Link to comment Share on other sites More sharing options...
Chris A Posted September 23, 2014 Share Posted September 23, 2014 (edited) "If you call a tail a leg, how many legs has a dog?" "Five?" "No, four. Calling a tail a leg doesn't make it a leg." (attributed to Abraham Lincoln) Perhaps there is a reason why there is a distinction made between a conical and straight-sided horn profiles? "Dr. Know says that might be a better question: just ask Dr. Know--but first, place your credits into the slot." (attrib. S. Spielberg. AI - Artificial Intelligence) http://en.wikipedia.org/wiki/Horn_antenna#Types http://en.wikipedia.org/wiki/Cone Edited September 23, 2014 by Chris A Quote Link to comment Share on other sites More sharing options...
djk Posted September 24, 2014 Share Posted September 24, 2014 The misteak (sic) most make is assuming an axis-symetrical (round ) horn is conical. The K402 sure looks like it's conical, except near the mouth. THERE IS NO WAY THAT IT CAN BE A TRACTRIX (especially near the throat). About 80 years ago Olson described a manifold horn of conical sections, which best describes the Altec MantaRay, EV HP series, etc. Quote Link to comment Share on other sites More sharing options...
Chris A Posted September 24, 2014 Share Posted September 24, 2014 (edited) It sure feels like deja vu, all over again... https://community.klipsch.com/index.php?/topic/91023-so-why-jubilees/?p=988175 https://community.klipsch.com/index.php?/topic/91023-so-why-jubilees/?p=988397 Edited September 24, 2014 by Chris A Quote Link to comment Share on other sites More sharing options...
Klipsch Employees Chief bonehead Posted September 24, 2014 Klipsch Employees Share Posted September 24, 2014 (edited) Right djk. I just don't know what the heck I am talking about. Edited September 24, 2014 by Chief bonehead Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted September 24, 2014 Share Posted September 24, 2014 (edited) Let's clear up some of the confusion. The term "conical" is being used in a strict sense by the "Chief". If you look at Olson's book from the 1930's, the function is referring to the cross-sectional area as a function of distance from the throat and not necesarily the shape or taper of the wall of the horn. Conical is defined as a cross-sectional area that increases by the square of the distance from the throat. Using this definition, then the straight wall horn would have a constant angle of a little over 25 degrees (if I remember correctly). Other shapes can look like cones (constant angle, like a cheerleader's cone) but have different angle. These would not have cross sectional areas increasing as a "conical" function. IOW, they do not increase as the square of the distance. I believe this is what the "Chief" is referring to. If you play with it a bit you could come up with rectangular horns with a combination of oddball tapers that could result in a conical expansion but not necessarily have straight walls of a fixed angle. This last point is just an aside. This definition by Olson and others is not always used in its strict sense. On the other hand, maybe I am simply wrong and "Chief" is thinking about something else..... Edited September 24, 2014 by PrestonTom Quote Link to comment Share on other sites More sharing options...
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