Preparing for Jubilee build

[Guest " "]

Hey guys - please let me add to the SUPER BUMP.....

One guy has offered CAD services - excellent; several have added their expertise in other ways - great - now, let me offer the CNC services. I have access to a CNC machine, in fact I built Bob's (BEC) CORNSCALA II cabinets (the second pair he picked up at the Pilgimage). I would be happy to help those in need; I WOULD however need adequate CAD drawings to proceed with connversion to CNC programming. I just was made aware of this thread (THANKS for the BUMP), having heard the Jubilee at the pilgrimage I am absolutely intrigued by them, and would LOVE to be involved in building a set/several sets as befits the need. If anyone here can point me to or assist with CAD, or is interested in getting these CNC cut (even as a kit) - let me know.

Let's ROLL this out.....

Chris

Dallas, TX

do you have a sample of the type of cad drawing you would need. maybe a good idea might be to send the before cad drawing and the after cnc input file used for the cornscala or any thing else for that matter, if that would help "template" the process. Would avoid having efforts on the cad drawing that had no bearing on the cnc file.

[D-MAN]

Did anyone ever come up with "final" version of the plans for the DIY jubilee? Any thoughts on the sound over time and if anything need to be tweaked? any thoughts on crossing at 800hz versus 1000hz? I finally found someone who has the tools to make one and I am ready to go!!!! tony

Tony, I agree with Duke - the cross-section (in this case "depth") of the throat channels are a physical limit to how high of a frequency that can pass. Once the frequency wavelength (and sub-mulitple thereof) is smaller than the smallest proportion of the channel, it is no longer acting as a horn.

You're best bet would be to limit the crossover point at 800Hz and lower IMO. I would go for 600-750 or so. Nice and "safe", well within the operating boundaries of the design.

DM

[popbumper]

Speakerfritz:

Understood, a few notes:

1) I need only line drawings; agreed there would be a lot of FLUFF added to the drawings that was not required. I can scrub drawings and extract if required.

2) Line drawings of specific dimension are fed directly into the CNC database, at which point they are"re-translated" into an "NC" file, which is the core data language containing all the x/y coordinates, etc.

Does that help?

Chris

[sunnysal]

I think mr. delgado confirmed 800hz as the crossover on the ones used in Klipsch demos HOWEVER my holy grail is to get something to cover 100-1000hz so that I can keep most of the fundemental ranges of the instruments I listen most often on one driver.

I thought that since the measurements PWK and Delgado showed in thier article should nice response from the bass bin from 35-1000hz that I could get away with it. I guess the concensus is that frequency amplitude measurements do not tell the whole story here and while it has output up to 1k it will not sound good up to 1k, am I hearing you guys right?

Guess I cross at 800 to a tractrix horn...or 300hz to altec 311? or simply buy the large format klipsch pro horn for the pro jubilee.

drats foiled again! tony

[Guest " "]

Speakerfritz:

  Understood, a few notes:

1) I need only line drawings; agreed there would be a lot of FLUFF added to the drawings that was not required. I can scrub drawings and extract if required.

2) Line drawings of specific dimension are fed directly into the CNC database, at which point they are"re-translated" into an "NC" file, which is the core data language containing all the x/y coordinates, etc.

Does that help?

Chris

there are various line drawings on this site. so getting you a line drawing is not a problem.

some validation of accuracy will be needed. either someone will have to step up to the plate and say they used the line drawing to the letter and all the parts fit together ok, or someone will have to make a test-fit unit to validate the drawing.

what are the costs considerations and fee structures that need to be explored?

[D-MAN]

Tony, that's getting into hands-on experience rather than to predictable mathematical behavior based on the design itself.

Horns have a historical limitation of about 3-octaves inherent in them due to the difference in wavelengths, even in a straight horn. The particular horns performance is limited by falloff at either one end of the 3-octaves or the other based on wavelength. As one gets to the point where the wavelength becomes smaller than the horn channel, it naturally starts bouncing around because there is enough room in the channel for it to do so. This is where the traditional 3-octave rule comes from. A horn channel wide enough for low frequencies to propogate efficiently will therefore not act like a horn for frequencies that are smaller than any of its particular channel proportions, that is the horn unloads at those frequencies, and the efficiency goes away, causing a very rapid falloff. Finding an appropriate 12" driver that can do both the lows we are accustomed to, and the upper freq. rollof that you need seems a more difficult task, but it could be seemingly be done.

A modern driver with a rising frequency reponse/power curve can help in this, of course.

The Khorn takes this a step further up to 400Hz, one of the few folded horns that go above the 3 octave rule. The folding techniques used in the Jubilee help to eleviate some of the high frequency muddling that typically occur in horn folds. The Jubilee takes it WAY further than that, and that naturally means a tradeoff is occuring SOMEWHERE and needs to be compensated for. Whether a "peaking" network could do this by itself, or an astute choice of drivers alone, who knows?

But a lower crossover point (600/750) would reduce some of the problems that a higher one would incur. My guess is that the Jubilee can be quite "picky" when it comes to drivers and the further you push it in extending the bandwidth, the more picky it is going to get.

DM

[popbumper]

Speakerfritz:

Cost considerations cannot begin to be approached until I had drawings in hand, though three areas would contribute: admin (time required to adapt the drawings into CNC programming, time to develop into a kit, associated instructions/drawings), materials (how many square feet of material, what type of material, finish (if any), and shipping (box size and cost, weight).

This is not something that could be done in a short time - it would require a few weeks of work (part time, of course, I have a full time job), but I'd take a stab at it!

Chris

[sunnysal]

Thanks d-man for the comments. I guess the "best" way to decide is to build the damn thing, use the drivers that PWK/Delgado used (or perhaps the pioneer driver that Bigdnfay used) and then listen/measure to decide on the upper crossing point. No small hint is where PWK/Delgado ended up crossing thiers (800). I plan to use an electronic crossover for the rig so I can play around a bit. The problem I have left is the horn, I need to find something that will work well for 300, 500, 800 and 1,000hz crossover points. Tony

[jorjen]

Count me in for a set of raw, Russian/Baltic/Finnish Birch bass bin kits, without question.

Are they done yet? []

If I am not mistaken, BigDnFay used the "Final" drawings prepared by Neandertal. We all know how nice those turned out. I will see if I can find an old email from him regarding this point.

Also, anymore thoughts on drivers for this cabinet? What is used in the bass bin that is in Hope(the Mahogany/Valerie version)? What is used in the Pro(KPT-KHJ-LF) bass bin? Can we use the K-22?

[D-MAN]

Tony, sounds like you have a good plan.

The hardest part of going the DIY route IME is the mixing and matching of the components to get it smooth. Not a job for the faint of heart, because it will make you crazy, let me say from experience.

It will really make you appreciate PWK (and Roy in the case of the Jubilee) and what it takes! You will undoubtably come up with additions and tweaks of your own, which I hope you will post for those of us interested in the Jubilee.

Chris, sign me up for a flat kit, too!

Dana

[sunnysal]

Jordan, One of my doubts is whether Neandertal ever coordinated with Bigdnfay in the creation of the drawings. I am not clear on that. I know Bigdnfay built his jubilees and seems to be happy with them. It ouwld be great for them to chime in on this point and point to the definitive plans. regards, tony

[jorjen]

Hey Tony,

Just found the old email from BigDnFay. He did in fact point to using the "Final" drawings produced by Neandertal for his own construction.

I have emailed Darrell with some questions and have asked if he might rejoin the thread and help out a bit. We will see.

[popbumper]

Once identified, please point me in the direction of the drawings, guys. I can start CAD at that point, and get them on CNC.

Chris

[Guest " "]

Speakerfritz:

  Cost considerations cannot begin to be approached until I had drawings in hand, though three areas would contribute: admin (time required to adapt the drawings into CNC programming, time to develop into a kit, associated instructions/drawings), materials  (how many square feet of material, what type of material, finish (if any), and shipping (box size and cost, weight).

This is not something that could be done in a short time - it would require a few weeks of work (part time, of course, I have a full time job), but I'd take a stab at it!

Chris

I just want to put it on radar.

i like the idea of having a pre-cut kit for forum members, and would like to help any way I can.

Once a agreed final version is identified, I would like to try out the line drawing to see if everything fits together.

I have most of the line drawings posted on the forum, and was in the process of reviewing for accuracy.

The jubilee plans are not as complex as a khorn. Most of the main cuts can be done pretty easily on my wall mounted panel saw. My saw has a new 80 dollar precision blade and an adjustable stop that can make square cuts to within 1/32nd of an inch. The few angles the jublie does have have, can be done pretty easily on my table saw.

And of course, as part of verifying the line drawing is correct, I will have a set that at least meets the forum spec.

[jorjen]

Both emails I sent Darrell(BigDnFay) bounced back undeliverable. Same addy I used no more than two weeks ago and they went through just fine. I doubt we will hear from him unless someone has a newer addy. I do not think he frequents the board anymore.

[jorjen]

This is the email I received from Darrell when I first contacted him about construction of the template for the Jubilee:

http://forums.klipsch.com/forums/thread/680813.aspx

Jordan,

Above is the forum link to the finished drawing of the jubilee. Constructing a template is very easy.The cost of shipping would be pretty high based on size and weight.

Using the drawing from the link, use a piece of MDF to make the base template. Cut your top and bottom slightly larger,attach the template to that piece and use a router with a flush cut bit to obtain the correct dimension. I used 1x1.5 pine strips and a chop saw to obtain the angles, then screwed them to the template in their correct position. All the internal pieces are the same length. All you have to determine is the width and angles on each end and the plans tell you that. I hope I explained this without confusion. Just think in 2 dimensions. I included a pic of the template I built as a guide. If you have any questions, I'll be happy to answer to the best of my ability.

BTW- Send me a pic of your finished cornscala. I may want to tack one of those together as a future project.

Darrell

[chops]

It is ok to use larger throat drivers on smaller horns, but not the other way around.

DM

I didn't know that was do-able. So if you had a 1.4" or 2" driver, you could mount that up to a 1" throat horn? What would that do to the sound?

Just curious. []

Charles

[D-MAN]

It seems sort of incongrueous, but its true.

The problem is caused by higher potential output capability from the larger driver going through too small of a throat and the resultant throat overload distortion.

The smaller driver in a larger horn doesn't suffer from that but rather diffraction effects in the horn, causing distortion which has nothing to do with the output level.

It would be best, of course, to use a matched combination, but there are times when some prefer larger diameter drivers with greater power handling capabilities in smaller sized horns for better dispersion characteristics and more control. It depends on the application.

I think it was on the Decware website that was touting a particular 2" driver on a smaller horn as being the cat's meow - they said it sounded better.

[chops]

It seems sort of incongrueous, but its true.

The problem is caused by higher potential output capability from the larger driver going through too small of a throat and the resultant throat overload distortion.

The smaller driver in a larger horn doesn't suffer from that but rather diffraction effects in the horn, causing distortion which has nothing to do with the output level.

It would be best, of course, to use a matched combination, but there are times when some prefer larger diameter drivers with greater power handling capabilities in smaller sized horns for better dispersion characteristics and more control. It depends on the application.

I think it was on the Decware website that was touting a particular 2" driver on a smaller horn as being the cat's meow - they said it sounded better.

Hmm, interesting. You learn something new every day. Well I do anyway![][]

[Guest " "]

It seems sort of incongrueous, but its true.

The problem is caused by higher potential output capability from the larger driver going through too small of a throat and the resultant throat overload distortion.

The smaller driver in a larger horn doesn't suffer from that but rather diffraction effects in the horn, causing distortion which has nothing to do with the output level.

It would be best, of course, to use a matched combination, but there are times when some prefer larger diameter drivers with greater power handling capabilities in smaller sized horns for better dispersion characteristics and more control. It depends on the application.

I think it was on the Decware website that was touting a particular 2" driver on a smaller horn as being the cat's meow - they said it sounded better.

thats intresting.

so I could take my 2inch throat k-4m adapter and mount it on the flang of an altec 511b?

The klipsch k-4m adapter lets you mount four k-55 drivers to a 2inch throat horn.