Al Klappenberger Posted March 9, 2010 Author Share Posted March 9, 2010 John, That sounds plausible, but that's WAY out of my area of expertise! It does sound more like something Bob would want to investigate. I doubt that driver is capable of much more though. Some versions had 2-piece phase plugs. That's the K55V with the solder terminals. I think it went up a little higher and removed the 9 KHz glitch. It's not even a 1-inch driver. I recall the bug screen measures about .85 Inch diameter. Al K. Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted March 9, 2010 Share Posted March 9, 2010 Well guys, my brains have officially exploded! Time to grab the gin and vermouth. What linker said. Extra Dry tonight.[D][:|] Quote Link to comment Share on other sites More sharing options...
deafbykhorns Posted March 9, 2010 Share Posted March 9, 2010 Al, the Atlas diaphram is actually 2", has anyone thought of opening up the throat of the K55? Perhaps someone with a cnc can fabricate a new cover that mimics the bolt-on JBL or does the K55 have enough tolerance to open up the .85 hole? BTW: I removed my bug screen, hopefully no insects will find a new home Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted March 9, 2010 Share Posted March 9, 2010 Boom3, I think it has to be "a" because the K401, or my horns for that matter, can't use a 2 inch driver and it seems there is just no driver that can directly replace on the K55 in a 1-inch format and be a real improvement. I think the main reason for that is simply that the K55 just isn't that bad! A good 1-inch format driver can be made to survive with a sharp enough skirt on the network filter, but what driver? I know of none that is designed to operate down to 400 Hz. How will a driver made to reproduce 800 Hz sound at 400 Hz even if it survives? The JBL 2426 specs say it can be used to 500 Hz, but that's still higher than 400 Hz. I think it's a small point, but one to consider since everybody is only considering the big BMS driver as if it were the only 2-inch driver available. It's not! There is a HUGE list of possibilities once you swallow the idea of moving to a 2-inch horn. About the K-5-J, I don't know, but PWK quite making it for some reason. Like the K400, it's an expnential horn. The modern trend is Tractrix horns. Al K. Boom3, I think it has to be "a" because the K401, or my horns for that matter, can't use a 2 inch driver and it seems there is just no driver that can directly replace on the K55 in a 1-inch format and be a real improvement. I think the main reason for that is simply that the K55 just isn't that bad! A good 1-inch format driver can be made to survive with a sharp enough skirt on the network filter, but what driver? I know of none that is designed to operate down to 400 Hz. How will a driver made to reproduce 800 Hz sound at 400 Hz even if it survives? The JBL 2426 specs say it can be used to 500 Hz, but that's still higher than 400 Hz. I think it's a small point, but one to consider since everybody is only considering the big BMS driver as if it were the only 2-inch driver available. It's not! There is a HUGE list of possibilities once you swallow the idea of moving to a 2-inch horn. About the K-5-J, I don't know, but PWK quite making it for some reason. Like the K400, it's an expnential horn. The modern trend is Tractrix horns. Al K. Al and others, Not too many years ago I was most willing to unzip my fly (freely display my ignorance) on this forum, so allow me expose myself again. This thread seems to be about the Tractrix equation horn with a 2" driver being superior to a small format exponential horn and driver crossed low. I have listened to the large format Tractrix horns and drivers, seen the measurments, and do agree. But I can't say that there isn't a 1" driver to best the K55 and cross at 400hz. Manufacturer specs for Pro drivers are very conservitive when applied to home audio. They spec the drivers in an attempt to survive the use and abuse in pro applications. There must/could be others, but all said for small format, the Altec 902-16A(Altec 500hz cross specs) beats the pants off of a K55. Crossed at 400hz 1st order or 120db slopes, loading exponential or tractrix horns. Don't trust my ear, I got the sweeps. Not to stir the pot because some are negitive about the 902 due to badly installed diaphragms. There are small format drivers crossed low that best K55's. Make no mistake. PS: Did I say how much I like my ESN dbb450 networks?[] PPS: In Hope last year Seti pointed to how simular the K-5-J mouth was to a 511b. ???? Quote Link to comment Share on other sites More sharing options...
BEC Posted March 9, 2010 Share Posted March 9, 2010 Terry said "I got the sweeps" Let's see them sweeps. Quote Link to comment Share on other sites More sharing options...
jwc Posted March 9, 2010 Share Posted March 9, 2010 I concur with the slammer I had an Altec 902-16B that bested the K55 on my cornscala dbb's. Also had it XO'ed at 400Hz......not even an extreme slope network. Slammin also used to crank the 902 with a -6dB slope network at XO 400 Hz. It survived somehow. jc Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 9, 2010 Share Posted March 9, 2010 I would also like to hear about the 1" drivers that can truly beat the K55 in our application. I have struggled to find a K55 replacement that is a substantial improvement. The closest I have found is the JBL 2470, and it sounds great, but down near 400 Hz, it does not perform real well. That's why I have been interested in Al's new efforts. I had been looking at a bass bin I could cross higher, closer to the real comfort zone of the JBL. If Als idea works, it could come down to cost on which way to go. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 9, 2010 Share Posted March 9, 2010 I concur with the slammer I had an Altec 902-16B that bested the K55 on my cornscala dbb's. Also had it XO'ed at 400Hz......not even an extreme slope network. Slammin also used to crank the 902 with a -6dB slope network at XO 400 Hz. It survived somehow. jc JC, were you guys using that Altec in a two way setup? I just looked at the specs and it claims 500 to 20 kHz! That's impressive. Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted March 9, 2010 Share Posted March 9, 2010 Terry said "I got the sweeps" Let's see them sweeps. Bob, I knew that it would be you the Altec fan[] to ask for proof and I am searching for that as I type. The sweeps were first posted by S. Fogg. Up a little late tonight aren't we oldster? Ether help me help me cover my bu!! with resurch or go to bed. smile No, I couldn't expect any resurch help from you girls.( Mike ) Having probs finding the Shawn sweeps of old but they do exist.. You saw them and remember them, but no, no way would you support me in truth..Don't expect you to trust my ear but you should. You got the hf,I got the mids. Hope to see you soon, tc Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted March 10, 2010 Share Posted March 10, 2010 I concur with the slammer I had an Altec 902-16B that bested the K55 on my cornscala dbb's. Also had it XO'ed at 400Hz......not even an extreme slope network. Slammin also used to crank the 902 with a -6dB slope network at XO 400 Hz. It survived somehow. jc Thanks for the support as to your ear and as to the fact that I am not barking mad. [8-|] The 902 works nicely, at volume, and crossed low. tc Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted March 10, 2010 Share Posted March 10, 2010 I concur with the slammer I had an Altec 902-16B that bested the K55 on my cornscala dbb's. Also had it XO'ed at 400Hz......not even an extreme slope network. Slammin also used to crank the 902 with a -6dB slope network at XO 400 Hz. It survived somehow. j JC, were you guys using that Altec in a two way setup? I just looked at the specs and it claims 500 to 20 kHz! That's impressive. , passaveRudy, At one point I think JC ran the 902's in two way above Jub-clone bass bins. I know that Seti ran 511b's/902's above Jub-clone bins two way. I heard them both and without any EQ there was nothing missing in the HF to my ear I use the 902's in three way with passave nets and a JBL2404 tweeter for the sizzel on the top. Just my taste. Hope that helps tc Quote Link to comment Share on other sites More sharing options...
Bacek Posted March 10, 2010 Share Posted March 10, 2010 I use the 902's in three way with passave nets What is your horn? Tractrix or 511? Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted March 10, 2010 Author Share Posted March 10, 2010 Guys, NOW WERE COOKING! I have had quite a few people put fancy 1-inch drivers of many types on my horns in Khorns. In fact, the very first guy to put a set in his speakers used a set of those high-dollar TAD drivers. I forgot the model number though. 9002 maybe? Anyhow, he was using my ES networks. I think the real danger to the delicate drivers like the 902 is the 1st order networks. Even then, levels below the 1 or 2 Watt level shouldn't hurt anything. All this suggests that my premise to this entire thread and to the justification for moving to a 2-inch horn is all wrong to begin with! If 1-inch drivers will do, why go to a 2-inch horn? This says the 2-inch idea is simply the "bigger is always better" school of engineering! I did side-by-side intermodulation tests on my JBL 2426j and the big BMS driver a while ago and found that the distortion only became measurable at 110 dB SPL. I needed to wear ear plugs just to tolerate the volume level! That led me to conclude that 2-inch horns were just for movie theaters, not home stereo! It's only now that everybody is talking about 2-inch horns that I am am forced to get involved. After all, what the market wants the market gets! I don't know very much about the design of compression drivers, so the subject of how to improve the K55 is out of my area of expertise. I have replaced a couple diaphragms in them and looking inside tells me they are just not built for any kind of advanced performance. If good 1-inch drivers will do the job and are already available, why even bother with the K55? Al K. I uploaded the IM distortion plots I did at 100 dB SPL. The distortion is higher in the 1-inch horn even at 100 dB SPL, but not bad. I really needed to go up to 110 before it got obvious.I will be doing these tests over again with all 3 drivers later this week. Since these plots were made I have gotten a nice B&K condencer mike that will tolleratre extremely high levels better than the mike I have been using. I'm pretty sure my mike wasn't overloading when I did these tests though. Quote Link to comment Share on other sites More sharing options...
Coytee Posted March 10, 2010 Share Posted March 10, 2010 If 1-inch drivers will do, why go to a 2-inch horn? This says the 2-inch idea is simply the "bigger is always better" school of engineering! I am probably tied with last place in the technical stuff but... would it be something to do with power/distortion? Analogy: 1971 Chevy Malibu with a 2bbl 307 ci. Strap a trailer hitch on it, load the trailer, move across the country and now, start to drive up the Rocky Mountains. The Malibu will probably make it through but at times, might be straining. Switch to a 1971 Oldsmobile 4-4-2 with 455 ci and 4bbl carb. Similar sized cars. Strap same trailer on 4-4-2, make same move. I'd suggest that this car would make the drive with a lot stress because of its extra power. (I used to have a '71 4-4-2 as described so am aware how quickly it could still pull away from a stoplight while pulling a trailer across the country) So, would the larger format driver be a more powerful driver and as such, be able to do the same work the 1" can do with less strain and therefore, less distortion? The 'bigger motor" analogy. Just asking since I don't know. Heck, even if I happen to have a point, I don't even know if the car analogy would be the right one to use! [] Just because something can play to 34,000 db's, doesn't mean it has to. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted March 10, 2010 Author Share Posted March 10, 2010 Coytee, I think your analogy is correct. The question becomes: how much is enough and how much money do you want to spend to get it? Al K. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 10, 2010 Share Posted March 10, 2010 IMD tests are only valid when both fundamentals are the same SPL... Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 10, 2010 Share Posted March 10, 2010 I think your analogy is correct. The question becomes: how much is enough and how much money do you want to spend to get it? Once one starts throwing money at a problem, instead of settling with a well engineered design (like the K55/K400), then I might argue that any discussion about "how much is enough" becomes more a justification of mediocracy striving for the image of refinement, rather than actually achieving it. The more I learn about speaker design and the problems trying to be overcome, the more I realize just how good PWK's grasp on the relative performance of all the variables involved is/was. And now we've got threads with self-proclaimed experts trying to figure out the differences between a 2" and 1" throat with absolutely zero discussion about the actual problems that are trying to be solved. I'm nowhere near an expert, but it's like watching guys talking about who has a better hammer for installing a screw... Btw, there's a million reasons why I think these discussions are good, but I had to wake up at 4:30 this morning (I'm usually up around 9am) so I felt I could justify sounding a bit cranky (although I'm not cranky at all) [] I just wanted to suggest that (good) speaker engineers don't sit around wondering which driver to use....they let the problem set and budget for the project determine the best compromise of all the variables involved. Quote Link to comment Share on other sites More sharing options...
Modified-Tractrix Posted March 10, 2010 Share Posted March 10, 2010 Al, If you want the best of both worlds perhaps you should fire up your calculator and design a 1.5" class horn. It is obvious from looking at the state of the art drivers from most manufacturers that the focus is heading that way. Just look at the better drivers from BMS, B&C, JBL...that have invested heavily in this format. Most company's 2" drivers use the same driver with a short horn section to get to 2". Much good can come from a 1.5" driver with the phase plug much closer to the throut of the horn. As a side benefit, the mighty klipschorn could find its way back to two-way with the right driver. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 10, 2010 Share Posted March 10, 2010 This thread is getting exciting. I'm the dummy in this class, so i'll keep the dunce cap for now. However, you smart guys keep talking. I'm paying attention. For most of us cost is a big factor, so the solution has to be something within reach of the average Klipsch afficionado. Quote Link to comment Share on other sites More sharing options...
jwc Posted March 10, 2010 Share Posted March 10, 2010 About 3 years ago, I curved out an Altec 902-16B on a 511 horn. I didn't check off-axis. What I found was that the output slowly started trending down below 600Hz. When it got to somewhere between 400-425Hz, the curved dropped off quickly. That driver worked "well" in a 3 way setup XO'ed at 400hz. jc Quote Link to comment Share on other sites More sharing options...
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