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D-MAN's Achievements

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  1. JC, that is a good question! The tubes are each 8" long, the Vb is approx. 4.5 cu. ft, I would guess. The volume is a bit tricky with this stuffing. Might go with longer tubes; I went with the tube size that Chris Munson (popbumper) used as most of the ported La Scala dudes reported that they preferred the shorter tubes. There is a noticable fall-off below the resonance of the tubes, not like a bass horn. It is a very steep cliff - you really notice it, unlike the gentler roll off of the corner horns. This could be from the Fr being too high (too small of a Vb) for the K33E to resonate at the expected tuned frequency, that's my suspicion, but its still quite smooth and entirely listenable. At this point, because I tried the KAPPA-C's which really "fit" the Vb volume, I won't know until I get the Crites in them. I didn't think that they would go well with the crossovers that I have, so I sent them home with my buddy as they were just taking up space. But they are a definite candidate for use in these. I used the 6" wide slot on those, as I would all drivers except the K33E and Crites drivers. I know that the K33E's are not resonating anywhere near the Kappa-C's in the volume that I currently have (but within a couple of Hz of the V2's (34 Hz Fc), I'd say). I used the commercial "Acousti-Stuff" in these instead of fiberglass, as they have open ports and I didn't want fiberglass being puffed out the ports. About 1-1/4 lbs in each cabinet. I'm not sure about whether its the equiv. of fiberglass or not. The K33E's could use more stuffing (4.8 cu. ft if I remember correctly), the Crites should be close as they currently sit. I'm also using the narrow slot for the K33E's. I will get around to checking wider slot variants too. But I have to say, MAYBE, or even PROBABLY, when properly tuned, the corner horn has met its match. These are very promising - I didn't expect them to compete effectively with the corner horns (I intended them as rear-channels). Test-wise, currently I don't have any test gear. It would help, certainly. Dana
  2. I think PWK was right, the measured K33(x) T/S parameters put it outside of the accepted workable horn formulas, so I would agree that it cannot be accurately modelled by most horn programs that I know of. It remains a matter for empirical testing. The Keele formulas, for instance, would predict the optimum efficiency of the K33E at a throat size (St) of 115 sq. in. and a Vb of rather large volume at 9343 cu.in. Not practical, in other words. This all changes when under pressure as in the Khorn and equivalents. I think that he's used to dealing with John Q. Public on the whole, so what he says may be watered-down quite a bit (for public consumption, as it were), but the gist of what he said is entirely correct IMO. DM
  3. Got a pair in the house, nasty-looking, but suprizingly sweet sounding. These pups can ROCK! Painted black with that spray epoxy with lumps in it. This will take some practice. Phenolic midrange diaphragm, K33E and a stock ALK crossover. JBL tweets are not going in these, I ordered some Crites tweets for these (hence the offset mid horn). Compared to the V2's (the corner horns), these don't go quite as low, but ran out of that nylon stuffing, so resonance isn't quite where it should be. I ordered CW1526C's from Bob Crites. We'll see how they do as they can resonate in a slightly smaller volume than the K33E. My buddy who built these is a bass player, and he was suitably impressed enough that he went back home and immediately started building himself a pair. We tried one cab with the Eminence Kappa 15C (4 Ohm) which I had sitting around and only one cabinet totally kicked tail. 30 watts was flabbergasting. These not only blow out matches, they blow the extinguished matchstick out of your hand! Real pant-flappers. I was amazed at how much air these can move. He also couln't believe how loud they were at 1/3 watt. The next day I got to messing around and discovered that I had wired one woofer out of phase. I was thinking that the K33E sounded a little weak. Now that they are both wired in correct phase, I no longer think that at all. Doh! These bass bins are on casters so they can roll around easily. I thought that raising the cab up off the floor would hamper the bass, but it is more than satisfactory, another suprize. The 400Hz 1rst order crossover may not be the best - seems that the bass horn goes higher. I had the same problem with the V2 so I was sort of expecting this, and on the V2, I had to go with a steeper slope crossover to compensate. Probably the same thing here. There isn't enough room in the back chamber to allow for a front chamber to be employed, so I'm probably stuck with the crossover solution. Too bad its the most expensive! My overall impression is that these will definitely give the corner horns a run for their money. They are just as efficient, and I think when properly tuned, these will perform just as well. They image better because they are not in a corner (apparently). Their ability to image and throw a very stable soundstage is better, and the fact that they are free-standing is a real bonus. Now to get a nice veneered set. These are butt-ugly. But in the dark... Dana
  4. Looks like 1985... (!) However, PWK is absolutely correct in his response, the T/S params of the K33(x) put it way out there into unpredicable territory when under compression such as in a Khorn. DM
  5. Interesting comments above. Let me think about those for awhile... Personally, I think the dynamic range of digital media and low noise level is far better than vinyl, but that's just me. See this letter from PWK posted by Freddyi on the audioasylum forum referring in part to digital technologies. DM
  6. Maron, well, I did say it was a viable alternative! For $200, I'd say hell yes! $750? - that would be a hell no! But that's just my opinion. You NEED to write this stuff down for posterity! Who is going to set us straight after you're gone?! Dana
  7. Well, that seems like asking for an opinion - and I just happen to have one available! In my opinion, due to the relatively narrow bandwidth involved (Khorn -6db @ 400Hz), I'd say no, it's NOT worth that kind of money for what you are going to get out of it (6 times the money as compared to a K33E). Do you REALLY think that you are going to get 6 times an improvement out of a TAD? Not likely, so it doesn't make economic audio sense (now that's a real misnomer!). The TAD is a stronger motor than a K33E, but it doesn't give any increase in power handling or excursion. Improvement - possibly, but more likely a change in "flavor". However, it looks good for a larger slot size, too, although it would probably be fine in the standard 3" wide Khorn slot. Is it a viable alternative driver for a Khorn - yes. Would you have to change the inductor on the crossover? yes. But as to whether it is worth the money... Throwing that kind of dough into a Jub would make more sense to me because it has an extended bandwidth capability that could make some use of it, seems to me... DM
  8. The link to D.B. Keele's AES papers is here: http://www.xlrtechs.com/dbkeele.com/papers.htm Here is his patent on the modified conical horn... (attached) - if it is the 1978 EV horn, that is! Dana Keele_1978_EV_midrange_horn.pdf
  9. I posted a link to your pdf file and plans in other forums. Many there will be interested in your work, I'm sure. Here's one: http://audioroundtable.com/HighEfficiencySpeakers/messages/3366.html I hope you'll post on it too, some people have already inquired about what we are calling the "ELENA horn". Dana
  10. Don't use the 811 in a vertical position! That isn't a diffraction horn, it's a radial! DM
  11. Note that the patent posted above is NOT the same thing as you are attempting to achieve, I only think that some elements are related. The patent doesn't have any mechanism to reduce reactance peaks, it is concerned mainly with having various reflex-ports that are separated in frequency also feeding into the horn channel. This would have no impact on your implementation, of course, other than simply having some of the same elements. Your implementation would be considered an improvement and is quite patentable, even as it sits, IMO (patents do not require scientific proofs, in the technical sense). They have to APPEAR to those schooled in the art that the elements involved in the combination would work as indicated and presented. They cannot "fly in the face of known scientific principles", in other words. How well the invention actually works is up to the market place to determine, not the patent office. In the case of a loudspeaker, it has to essentially make noise in order to qualify as "work" for the patent office. It also has to be an improvement to the state of the art. I am relatively assured that there is no patent that I know of that attempts the solutions to the problems you suggest in the same manner. But then, I'm not a patent attorney, either. But perhaps you should talk to one. Dana
  12. Ok, I read the PDF document (more than once) and I think I have a handle on what you are trying to acheive. Let me paraphrase the issues for others for the sake of discussion... The purpose for the thing is that it is an attempt to cancel the reactance variations typical of short horn pathways, this being exascerbated by the fact that a reflex-ported front-horn cannot be effectively reactance annulled due to the requirements of the Fr (cabinet resonant frequency) needed to "activate" the reflex ports at the desired frequency, that frequencybeing well below that of the front-horn's Fc. Did I get that straight? The use of "tapped" frequency-specific filter cavities along the horn pathway are tuned to frequency values that would appear as peaks in the frequency response curve and are absorptive at that tuned frequency, hence removing the "peak" in the response at that frequency, and other active tuned reflex-ports are for "filling in" troughs if needed? The problem I see is that we can't determine the values needed without a frequency curve and a reactance curve by frequency. Preferably, we need a set of curves showing the "without" (before) and then a set showing the "with" the cavities (the "after"). That is all that you are missing in the document, which you already know, of course. The missing "proofs"... From what I can tell, it is a valid approach, somewhat unweildy though without test equipment, but in theory, it should get the job done. The question is, is it too complicated to be economical? I think it is somewhat related to this reflex-ported patent (attached). DM
  13. JC, I used mirrors and a flash light to calculate the desired angle on the full-size drawing. The expanding channels of the horn (not including the length between the reflectors - no expansion there) is somewhere around 39 inches (if memory serves), measured center-of-channel. It is about 5" shorter than the Jubilee expanding channel length. I didn't include the non-expanding portions of either design in the measurements because it has no effect on the horn flare itself, its just a connector. Dana
  14. Mozart is dead, so I can't listen to him. I can listen to others playing his compositions. And THAT isn't about those doing the playing, is it?! Improvisational Jazz, however, it is EXACTLY about the person playing it, even down to an instrument-by-instrument level... Sharing? No, its a matter of "listen to me and what I can do". Improvising is a VERY personal thing. You can call that "sharing" but it changes nothing. For instance, classical is about the music - no personalities involved - but - improvisational jazz is always about the person playing it. That's it's POINT, for crying out loud! Other analogies - let's see - here's one: I PAINTED this painting on the wall. You can look at it if you want, AND I don't care what you think about it because it's finished and cannot be changed to suit anybody, even me. It's what it is and nothing more. But now let me PLAY a piece that I composed, that I DO care about what you think of it, I'll add flourishes that I think you'll like, I like playing them anyway, even if you don't. I'm the one performing, and YOU are the one listening. One is personal, one is not. DM
  15. I wouldn't worry about it - there is no way to get through the final exit channel "bend" without bouncing off a channel wall anyway. I chose a "best case", as well as I could. The geometry won't permit any better and that's why I'm not concerned that you could have done anything with the outside reflectors inadvertantly which would have any detrimental effect on the response. It's the final terminus "bend" that makes it track along with the Jubilee, anyway. That is the one single channel feature that they both have in common. The REAL question is, do I change the plans to follow YOUR model exactly, or stay with mine? I think the differences are far too small to have any noticable effect. If I understand the differences correcly, all you did is adjust the path from what is shown above to a more axially-aligned one. Still going to bounce off the terminal channel bend anyway... see what I mean? Nothing we can do about it. Well, that is IF we don't change the footprint. I'm happy with what we got. Dana
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