dragonfyr Posted June 15, 2005 Share Posted June 15, 2005 Thanks for that link!!! Fills in quite a few holes! Bear with me for one or two more 'silly' questions! When the Jubilee clone was being discussed, as I remember it, there was talk of a motorboard design both accomodate 2 -12s and 3-12s. For clarification: 1) was the passive radiator mentioned in the linked discussion a substitute for one woofer (ie 1- 12 woofer + 1-12 passive radiator), or 2) was it the third driver referred to in the clone 3 driver motorboard (ie 2 -12 woofers + 1 passive radiator), and 3) was the 2-12 woofer configuration deemed appropriate primarily for the increased sensitivity in larger commercial applications? 4) or have I missed it entirely and there is some other method to the madness!?? Additionally, I guess I am still preoccupied with verification of the throat loading to remove that one last variable! Thanks for the additional info and clarification! Quote Link to comment Share on other sites More sharing options...
D-MAN Posted June 15, 2005 Share Posted June 15, 2005 Speaking of imaging, one needs to remember that the standard Khorn is a 45 deg. fixed BAFFLED horn mount on the top end. The Jubilee is not subject to BAFFLE diffraction as its top is unbaffled (i.e., the free-standing horn). Believe me, there is a whole world of difference with imaging with unbaffled horns on the top end. So what has been said about the heard "differences" makes sense when you look at it in context. DM Quote Link to comment Share on other sites More sharing options...
WMcD Posted June 16, 2005 Share Posted June 16, 2005 In that thread I was talking about the two Jubilee we heard in Hope. Feb 16, 2001. My comments about chronology in my post appears incorrect. My impression at the time is that we heard ordinary bass units and not ones with passive radiators. There was no mention of passives at the time. Of course impressions from a minute of viewing and memory are often inaccurate in the long run. Trey showed us (for a minute) that the hard wood units in the auditorium were actually not hard wood construction of the bass horns at all. It was a a very clever hardwood facade where we see hardwood (ribbon mahogany?). The side grills were also detachable. A very, very nice job. Please note Andy reports about the same. Underneath was what I took to be the theater version. What is inside, we can't tell. I sure didn't look like a prototype. My impression may have been corrupted (or mis-directed in the argot of stage magicians) by the fact that we were taken through the factory where there was a stack Jubilee without drivers. Jim Hunter asked me to keep up with the group when I lingered at them. Smile. Desspite my caviats above, I'm conviced we heard ordinary theater Jubilees. I'd like to point out that the use of two drivers makes the use of a hatch on top and bottom unavoidable. So if there is a home hardwood Jubilee, there is going to have to be a facade at least on top. Best, Gil Quote Link to comment Share on other sites More sharing options...
edwinr Posted June 16, 2005 Share Posted June 16, 2005 ---------------- On 6/15/2005 9:18:18 PM psg wrote: Guess I need to get out more... ---------------- Don't we all! I guess I should qualify that comment about imaging. I'm suggesting the imaging is not as precise as the smaller BBC style monitors and other book shelf type and floorstanding loudspeakers. And probably not as precise as I've heard with ML's. But this precise imaging, in my view, tends to be a feature of 'speakers that lack the large scale and dynamics of the Klipschorns. This would also be room dependant, I guess. Quote Link to comment Share on other sites More sharing options...
formica Posted June 16, 2005 Share Posted June 16, 2005 ---------------- On 6/15/2005 9:55:08 PM dragonfyr wrote: When the Jubilee clone was being discussed, as I remember it, there was talk of a motorboard design both accomodate 2 -12s and 3-12s. For clarification: 1) was the passive radiator mentioned in the linked discussion a substitute for one woofer (ie 1- 12 woofer + 1-12 passive radiator), ---------------- No... ---------------- 2) was it the third driver referred to in the clone 3 driver motorboard (ie 2 -12 woofers + 1 passive radiator), and ---------------- Yes... as far as i know... there were two woofers and one PR in the home prototype design What the PR accomplished in this configuration is what isn't entirely clear... Rob Quote Link to comment Share on other sites More sharing options...
dragonfyr Posted June 16, 2005 Share Posted June 16, 2005 Thank you! Just a guess...Would they be attempting to use the PR in lieu of a port to tune the dog house in a manner similar to what a few have done with the modified 'ported/reflex' loaded LaScala enclosure in order to reinforce the LF response? A somewhat rhetorical question, he said, begging the obvious! Hmmm!? All the more reason to look inside and get the details of the throat as I am fascinated with the commercial loading of this unit!! Quote Link to comment Share on other sites More sharing options...
6foot8 Posted June 16, 2005 Author Share Posted June 16, 2005 Thanks Parrot, I got a couple of disposable cameras last night. I'll be taking pictures this weekend as I make the install permanent. I'll get them on a cd and then on Monday we can get them uploaded to the board. Quote Link to comment Share on other sites More sharing options...
6foot8 Posted June 16, 2005 Author Share Posted June 16, 2005 Hey Edwin, Thanks, I do like the vintage BGWs. I played around with the 750B, 750G and 250E as well as NAD 218 THX, Crown DC300, Dynaco ST70 and an Onkyo M504 on my La Scalas before the Jubilees arrived and I thought the 250E was the best sounding and the most suitable of all for this application. I was very surprised at the BIG difference (and I mean BIG) in bass performance on the La Scalas when switching from the NAD 218 (which was the amp I had been using for a long time in that setup)and the other amps to the BGW 750B. The 250E still had produced better bass than the NAD or Onkyo, but was a better sounding amp in the critical mid\hf range than the 750B. I was considering selling my La Scalas due to the (how can I say this in a politically correct way here) "perceived" lack of bass...but with the 750B and the bass pot cranked over most of the way I was very very surprised at the fullness of sound I had finally achieved with these speakers after owning them for so long and with so many different amp\preamp combinations. I'll admit I was never using a $20k Manley Labs amp or anything like that but I am still impressed at the difference with the BGW. My Thorens in currently "on the shelf" for lack of use, but is stock with the exception of better interconnects I had installed about 20 years ago and has a B&O cartridge. Quote Link to comment Share on other sites More sharing options...
formica Posted June 16, 2005 Share Posted June 16, 2005 ---------------- On 6/16/2005 2:34:54 AM dragonfyr wrote: Just a guess...Would they be attempting to use the PR in lieu of a port to tune the dog house in a manner similar to what a few have done with the modified 'ported/reflex' loaded LaScala enclosure in order to reinforce the LF response? ---------------- Actually it wouldn't... but that would have been my initial thought as well. Given that the PR is in the throat of the horn, it will be controlled by the horn's Fc. I agree with previous posts (in other threads) that it was possibly used to increase efficiency (a typical benefit of ported systems at tuning) of the bass bin or perhaps for some other gain PWK found by adding backchamber compliance. I cannot say. I wish someone from Klipsch would clarify the reasoning between the two versions? I'm sure D-Man (djk, Gil, etc...) could elaborate much more on this than I can... Rob PS: the Jubilee - D.I.Y. drawing project (work in progress) thread has a wealth of info in it as well... Quote Link to comment Share on other sites More sharing options...
Parrot Posted June 16, 2005 Share Posted June 16, 2005 ---------------- On 6/15/2005 8:50:47 PM edwinr wrote: Nice pics, Paul. ---------------- I think the credit for the third one probably should go to Tony Reed. And he first posted the one with Miss Valerie, too, I think. Here is a short thread about Tony auditioning Miss Valerie's Jubilee. By the way, she has only one. http://forums.klipsch.com/idealbb/view.asp?topicID=61053&forumID=74 I can't begin to answer any technical questions on the Jubilee, but there are quite a few threads on it spread across several different Forum sections. Unfortunately I don't think you'll get anything definitive, finalized, from the threads because the engineers who would presumably be in a position to know are not divulging the finer details. The thread Formica references is one of the best ones. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 16, 2005 Share Posted June 16, 2005 A couple of things are interesting to me. One is wondering about how the theatre Jubilee compares to the two way home Jubilee that I've heard. The two way version would certainy be a simpler semi-DIY project. That has seemed to be an attainable goal by purchasing the bass bin from Klipsch for $1500 each. It could be left unfinished for a veneer job on the front and top. The biggest challenge seems to be finding the right horn to use with the BNC hf driver. I've been looking around on the internet and haven't found anything, save for some very high dollar (IMO) wooden horns. What I've been wondering is what would be involved in duplicating/fabricating an existing horn that was already the right spec. How easily could that be done? I wouldn't be bothered in the least by having a black composite horn on top of the bass bin. To my sense of aesthetics, it's somewhat understated and nice utilitarian approach. Quote Link to comment Share on other sites More sharing options...
Deang Posted June 16, 2005 Share Posted June 16, 2005 What I've been wondering is what would be involved in duplicating/fabricating an existing horn that was already the right spec. How easily could that be done? Well, a good start would be for you and Tony to snag the horn off that thing when she's not looking. The other way is the legitimate way, and that started with the phone conversation I had with Joshua Hall of Klipsch a few months ago. I got some info from R. Delgado too -- and it's all sittin in my back pocket until you return my phone call. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted June 16, 2005 Share Posted June 16, 2005 I can only speculate on the benefit of a PR or even a port in the horn throat of the Jubilee. The expected effect would be an increase in back chamber compliance (i.e., more compliant; larger in area volume, easier to compress, etc.), effectively lowering the back chamber resonant frequency below the cutoff of the horn. This would allow for the higher Fs drivers to be employed given the same throat size, etc. The passive would not have much other effect on the output other than to somewhat increase the bandwidth of the drivers somewhat. Remember that its not trying to go lower in freq. than the horn's fc which is fixed, its trying to increase the bandwidth of the active drivers or allow better performance of certain drivers. Why bother? Good 12" woofers capable of below 40Hz work are rare and somewhat expensive. Any mod that allows a wider or less expensive approach to driver selection might be useful. That's my guess. DM Quote Link to comment Share on other sites More sharing options...
WMcD Posted June 16, 2005 Share Posted June 16, 2005 D-Man, that is a very interesting theory. I'll have to think about it. On one hand, you have passive "giving" a bit against its suspension. So it might look like an extra volume. On the other hand, the throat side of the passive sees the pressure in the throat. Maybe that presses back to eliminate the effect. I'll cogitate. = = = = As a general observation: The K-Horn has an Fc of about 48 Hz. But the driver resonance raw is down at 35 Hz. It looks to me like the overall resonance in the box is 35 Hz too. The mass reaction of the horn may be the reason. It seems to me that the K-Horn gets a boost in driver motion by the mechanical resonance at a point below Fc. Some thing similar to this appears to be going on in the Valerie patent document. If you look at the SPL curve there is a little bump at the low end. I think that is the driver resonance. Again this is below the Fc. The conclusion I reach is that the K-Horn and others are not placing the driving system resonance at Fc at all. It is well below it. My other conclusion is that there is no particular focus on "reactance annuling". The reason might be that in short horns, the reactance is going plus and minus. So annuling would hurt in part of the frequency curve. = = = One of the qualities of the Jubilee is that it has the same footprint as the K-Horn. I infer that PWK had a goal of better performance in the same size. It is easy to get better performance in a larger size. Evidently he didn't want to do that. The issue created is that back chamber volume is a critical constraint. I thing that is why the raw driver Fs is so low (19 Hz). My guess is that a lower mechanical system resonance would have been desired, but it is just about impossible. My guess is that the passive is tuned to resonant below the active drivers. That would give a little boost down low. = = = = Best, Gil Quote Link to comment Share on other sites More sharing options...
Deang Posted June 16, 2005 Share Posted June 16, 2005 My guess is that the passive is tuned to resonant below the active drivers. That would give a little boost down low. It also increases power handling. Quote Link to comment Share on other sites More sharing options...
djk Posted June 17, 2005 Share Posted June 17, 2005 "Good 12" woofers capable of below 40Hz work are rare and somewhat expensive" A driver with a free air resonance of 100hz will work in a horn as low as 10hz if the Qts is 0.2 or lower, and the horn has the correct taper rate and mouth area. (Fs/2)*Qts=Flc (after Keele) Quote Link to comment Share on other sites More sharing options...
Tony Reed Posted June 17, 2005 Share Posted June 17, 2005 ---------------- On 6/16/2005 6:37:01 PM DeanG wrote: The other way is the legitimate way, and that started with the phone conversation I had with Joshua Hall of Klipsch a few months ago. ---------------- Wait a minute... you mean there's a legitimate way to get this horn? Let's hear more about this. Tony Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 17, 2005 Share Posted June 17, 2005 ---------------- On 6/16/2005 6:37:01 PM DeanG wrote: What I've been wondering is what would be involved in duplicating/fabricating an existing horn that was already the right spec. How easily could that be done? Well, a good start would be for you and Tony to snag the horn off that thing when she's not looking. The other way is the legitimate way, and that started with the phone conversation I had with Joshua Hall of Klipsch a few months ago. I got some info from R. Delgado too -- and it's all sittin in my back pocket until you return my phone call. ---------------- Deano, Shoot me your phone numbers on PM or e-mail. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted June 17, 2005 Share Posted June 17, 2005 Gil, I don't know why one would want a passive in a horn throat. But seems to me that trying to push a lower frequency through the horn below horn Fc is somewhat ineffective as far as increasing the low frequency response, so I'm assuming that isn't the purpose. It could increase the overall efficiency of the output, though. Perhaps that was its only goal, I can't say. My guess is that it would not be needed as 2 x 12" woofers would be quite efficient by themselves, I should think. I suspect that it has to do with using a smaller throat and/or opening than optimum in an effort to increase the bandwidth of the drivers. I am just putting it forward as a theory. DM Quote Link to comment Share on other sites More sharing options...
dragonfyr Posted June 17, 2005 Share Posted June 17, 2005 ---------------- On 6/17/2005 1:16:44 PM D-MAN wrote: ...... It could increase the overall efficiency of the output, though. Perhaps that was its only goal, I can't say. My guess is that it would not be needed as 2 x 12" woofers would be quite efficient by themselves, I should think. I suspect that it has to do with using a smaller throat and/or opening than optimum in an effort to increase the bandwidth of the drivers. I am just putting it forward as a theory. DM ---------------- I am having trouble determining the value of the PR as well, and its mention caught me by surprise. And with its, how should I say it, I know, try 'abyssmal' transient/impulse response due to the compressive nature of air, it would not be contributing a significant output that would contribute to any high quality output from the horn. And it sure seems that adjusting and simply building the cabinet with a 'better' throat size would be easier, cheaper, and without the additional 'less then optimal' PR contributed characterisitcs... This is not meant to argue! It is just that I can think of better and cheaper ways to do each, and I can't justify the inclusion of the PR. But hey....I don't think it was used simply because they had a few extra lying around All of which has me itching to see a good well-lit detailed picture of the motorboard and throat topology complete with dimensions! Quote Link to comment Share on other sites More sharing options...
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