Deang Posted January 2, 2006 Share Posted January 2, 2006 "This is what I mean about Klipsch being on to something. They apparently have discovered that the K55 is past what it can do really nicely past 4500hz." Oh, I think PK himself knew this 30 years or more ago, and I'm sure Delgado and Hunter have known for just as long. Remember, to PK everything took a back seat to efficiency. You can't add elements to sections of a filter without increasing insertion losses or "stealing" energy from the driver(s). Don't think for a second anyone around here is making any ground breaking discoveries. We may like what we are hearing, but no question PK would have b!tch slapped every last one of us.As far as cutting the squawker's upper end response with the use of a BECpass filter -- it's nice to see Bob caving in to new ideas. Hey, new tweeter or not it's the quickest way to improvement in the midrange.Since I don't have Bob's new tweeters yet to play with I can only go with what I'm hearing using the Beymas and Trachorns. Since Wednesday I've already tried several first order interations including Bob's modified A and to my ears at least 4500Hz just sounds too "tweety". Like I said earlier, the new Klipsch 4500Hz transition is 36dB/octave, and shouldn't be construed to mean anything at all when applied to 6dB/octave filters -- it's apples and oranges. Try not to laugh too hard -- it's just a hacked out prototype. I always end up back with constant impedance, and with the Beymas -- the traditional transition points still sound best to me. 3uF on the Beyma sounds "just right". Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted January 2, 2006 Share Posted January 2, 2006 Dean, Thanks for your take and a word about the history of this. Here's what I did... changed the 2uF tweeter cap to 4uF. Added a 500uF inductor to the squawker. Now... is a 6db slope stock in the type A? Does this mod accomplish the same slope at 4500hz. What would you expect to be different about the Klipsch 36db slope at 4500hz? On the 3uF for the Beyma, what does that make the cutoff frequency? 5000hz? Thanks in advance for pardoning my ignorance. I am not a plain old geek, but also a plainly ignorant geek. I actually stretched the repoitoire of my technical skills to make this crossover mod. I could become dangerous with a soldering iron, if I ever heat one up, that is. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted January 2, 2006 Share Posted January 2, 2006 Dee, I have come to the same conclusion, that 4500hz seems to be the magical point. My La Scala's have never sounded better!! Lar sweet ain;t it? It was a surprise and exceeded my expectations. Of course, I am among the most easily entertained...:-) Quote Link to comment Share on other sites More sharing options...
Deang Posted January 2, 2006 Share Posted January 2, 2006 Assumed "history". We know from the old Patents that PK played with cutting the squawker, and we know that Klipsch does it now. It just seems that as soon as they didn't have to contend with him anymore they did it. At least, that's what it looks like. At any rate, DIY'ers have been doing it for some time. "Now... is a 6db slope stock in the type A?" Yes. "Does this mod accomplish the same slope at 4500hz." Yes, but the addition of .5mH (500uH) between tap 4 and the squawker terminals also adds a 6dB/octave lowpass for the squakwer to roll off its upper end (at 4500). The 13uF and .5mH form a bandpass (even though 13uF is on one side of the autoformer and .5mH is on the other). What would you expect to be different about the Klipsch 36db slope at 4500hz? A lot less energy (voltage) going to the tweeter. "On the 3uF for the Beyma, what does that make the cutoff frequency? 5000hz?" No, about 6100Hz, but I'm running JBL 2470's that go out to12kHz. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted January 2, 2006 Share Posted January 2, 2006 Thanks Dean. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 2, 2006 Share Posted January 2, 2006 Guys, There is a concept here that Dean is hinting at. It's called "equivalent noise bandwidth". The total energy that get through a filter is the sum of all the energy that goes through it. A very gentle slope filter (6 dB/octave) has a much wider noise bandwidth that a filter with the SAME cutoff frequency (or bandwidth) by steeper slopes. More total energy gets through. The computation to determin it is to integrate, that is to sum up all the energy that is less than 60 dB down the filter's skirts. This includes the passband, of course. That amount of energy is equated to a filter of SOME bandwidth having infinite slopes, zero loss and which pass the same amount of total energy. BTW: The losses in the filter count! Loss reduce the equivalent noise bandwidth becasue some of the energy doesn't get through the filter equating it to a narrow bandwidth.Al K. Quote Link to comment Share on other sites More sharing options...
BEC Posted January 2, 2006 Share Posted January 2, 2006 I should probably put in a cautionary note about this point. I would not suggest crossing over to a K-77 at 4500 hz using a gentle slope crossover. We are doing that with the new tweeter that can stand many times the power that a K-77 can. Now, having said all that, I have been using a K-77M and one of the new tweeter prototypes crossed like that because I am comparing the sound between the two. I also have several dozen K-77 diaphragms in the parts drawer, so if I blow one, no big thing to me. Michael and I were pleased to have Daddy Dee and Tony Reed here for some listening on Saturday. Dee mentioned that we spent a good amount of time listening to tunes, but, he did not mention that much of that listening session was with the squawker disconnected on the Cornscala. In that configuration, and with the ability to operate a switch going from K-77 to new prototype tweeter, a real sound comparison is possible. To my ears, in this test, the new tweeter is really producing notes and the K-77 is mostly just making "tinny" noises. Bob Crites Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted January 2, 2006 Share Posted January 2, 2006 Ithe K-77 is mostly just making "tinny" noises. Bob Crites Exactly ...! Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted January 2, 2006 Share Posted January 2, 2006 did i forget to mention ... I detest the K-77 ...??? Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted January 2, 2006 Share Posted January 2, 2006 Al, Thanks. I'm trying to digest what you are saying here. But, it's no reflection on what you say... just my slow and ill equipped mind. :-) Heck, I didn't even know Dean was hinting at anything. Bob, To my ears, your assessment of the K77 and the new tweeter rings true to me. the K77 sounds tinny in contrast. Another thing that was surprising to me was listening to the new tweeter and woofer w/o a midrange. the bottom end of the new tweeter is demonstrated to be impressive, to my ears. Quote Link to comment Share on other sites More sharing options...
Tony Reed Posted January 2, 2006 Share Posted January 2, 2006 Replacing the K77 with this new tweeter is a no-brainer. Big, big difference for the better. Tony Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 2, 2006 Share Posted January 2, 2006 Dee, The idea of noise bandwidth as it relates to loudspeaker drivers is really undefined to me with respect o its sound. It definitly relates to the power handeling of a driver though. The K55 is a tank and you won't hurt it no matter what you do, but the little K77 tweeter is another matter. Crossing it below 6000 Hz is subjecting it to more total energy. A lower crossover filter with equivalent noise bandwidth to an AA tweeter filter would require an extreme-slope filter. You can't really do that either becasue a lot of K77s just won't go that low! Bob's new tweeter will. AL K. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted January 2, 2006 Share Posted January 2, 2006 Al, Thanks for saying more about that. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted January 4, 2006 Share Posted January 4, 2006 I am really happy with the sound of my Khorns. Klipsch was really onto something when they stopped making the K55 do duty above 4500hz. I don't think I knew what I was hearing until I wasn't hearing it any more. Of course, it takes a competent driver to pick up there at 4500hz. I don't quite understand the tech involved with the 6th order filter? 36db slope employed in the AK-4 network, but can appreciate that it is able to make the K77 workable here. That is some great crossover work to accomplish that. The problem there is just the the K77 is not a very musical driver compared to the Beyma or the Crites. The Beyma is a very sweet sounding tweeter. I've been comparing it for some weeks with Bob's tweeter prototype. Every time I put the Beyma back in the system, I think, wow that is sweet. Bob's tweeter is able to pull off something that I have not heard the Beyma do. That is in extraordinarly realistic and live sounding cymbal strikes and cymbal percussion of different types. At first the difference caused me to do a double take. I don't know if the difference is the extended frequency response of the prototype.... I didn't think I could hear much in those frequencies at best. But whatever it is, I am hearing something that is a delight to my ears. Al or Dean, I haven't put the Beyma back in my system since I changed the type A crossover to cross at 4500hz. I know the Beyma bottom end should be 5000hz. Would you advise against trying it out in the crossover at 4500hz? Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted January 4, 2006 Share Posted January 4, 2006 I'd say, DD ... that it is the lower octave of response that you like outta that tweet ....... Quote Link to comment Share on other sites More sharing options...
Deang Posted January 4, 2006 Share Posted January 4, 2006 "Would you advise against trying it out in the crossover at 4500hz?" At the power levels we run I seriously doubt the Beyma would have a bit of trouble with it. The tweeter that Bob is using is the Eminence APT-50 which is a 105dB tweeter. You guys are running this thing unattenuated, down to 4500Hz -- and 1st order to boot. So yeah, I bet you have cymbals coming out the wazoo.[] Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted January 4, 2006 Share Posted January 4, 2006 Thanks Dean. Yeh, actually new tweeter got my attention on the musicality of the cymbals when I first had it in crossed at the standard 6000hz. Quote Link to comment Share on other sites More sharing options...
ricktate Posted January 20, 2006 Share Posted January 20, 2006 So when i order Bobs new tweeters what do i need to do to my AA and ALK crossovers to take advantage of the new crossover points?Is there an easy fix for the crossovers to get the crossover points where you guys think it should be?Icant seem to down load Bobs schematic on this thread.Thanks for any help .Rick Quote Link to comment Share on other sites More sharing options...
BEC Posted January 20, 2006 Share Posted January 20, 2006 Rick, No modification of any type would be required to use the new tweeters and see benefits compared to the K-77. You can just install and listen. If you like the sound of the new tweeter as much as some have liked it, then you may want to bring it in a bit earlier and you might want to roll off the midrange a bit sooner. This mod will be very easy on type A or AA crossovers I have built and will not require even any soldering. Al would have to comment on how it would be done with his crossovers, but again, no mod would have to made to use the new tweeter on Al's crossovers. Bob Crites Quote Link to comment Share on other sites More sharing options...
formica Posted January 20, 2006 Share Posted January 20, 2006 As far as I know, the mold to build the new horn is being manufactured now. Hopefully, I can provide good numbers of the new tweeter with the new horn in January. Price will be $150.00 per pair plus shipping. Bob Crites How are they coming along? Will be the "horns" be a metal alloy or plastic? Do they still require the use of the Z-brackets on the later model Klipsch? $150 per pair? wow.. i thought they were $150 each! I agree that 75$each seems reasonable when compared to used K77s on eBay but I can understand aiming for that price not to scare away potential buyers... given the driver itself sells for under 30$. Custom castings are pricey but I'm sure Bob knows what he's doing. I'm looking forward to reading some detailed comparisons esp to the JBL 2404H (that retails for 175$ more per unit) Keep up the good work... ROb Quote Link to comment Share on other sites More sharing options...
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