Did anyone here work out the Jubilee throat-vented hornresp model and how it might be applied?

[anatech]

Hi Freddi,
I design and repair tube product as well. I play with tube amps, and they are fun.

The reason most people you hear from use single ended and low power tube products on horn loaded systems is purely to get decent volume levels out at lower distortion. As you are well aware, distortion in a single ended anything goes up rapidly with power output. The same for P-P tube, but not as quickly. You don't hear from people using solid state or tube P-P as much because they are happy and really have nothing to discuss. Given they are the only options for reasonable sound pressure levels for the single ended crowd, why would this surprise you?

Enjoying a horn loaded system has nothing to do with what you drive them with. It is the best option for single ended any day, but that doesn't exclude them from being used with any other amplification.

Output transformers for single ended are really at a disadvantage because they have a constant magnetizing current - not good for low distortion. They aren't the best for P-P, but they can be a lot smaller as they don't need as much inductance (which brings up FR issues too). In the end, an output transformer is a necessary evil, OTL being a really bad option.

 

[freddi]

Yep. Do you know the approximate parameters of Jubilee's woofer?

I have a question = does the following model using an "R-J" show one way (perhaps very limited) of modeling a throat vented horn? Does it look legit?

 

[anatech]

Hi Freddi,
No, I don't. I would be capable of measuring the TS parameters if I had one to test.

To be honest, I would love to see one I could handle and test.

I never did design horn loaded enclosures, just B4 and sealed boxes. The design requirements were for more compact enclosures than a horn loaded type. An English engineer I knew used Electrovoice drivers in horn loaded boxes in the early 1980's. Really nice, really expensive drivers. I got him on low frequency extension, he was all over me in efficiency. His enclosures were at least twice the volume of mine using a smaller driver. They wouldn't fly in the 1970's, 1980's or 1990's markets at all. WAF was in the basement. Still would be! lol!

 

[freddi]

Henry Kloss and his original KLH stuff are among my all time favorites - and not too big either.

 

[anatech]

LF response has to do with mouth size. So low frequencies do not come from small horn loaded boxes. That's why they were corner type speakers, the room became part of the mouth.

The Jubilee speakers are free standing. They don't need corner positions.

 

[Ivo]

Anyway, you can't call the Jubilee "legacy" at all. These are a totally new animal, more like the RP-7III and other new systems. Just awesome.

I believe you. I also think Roy Delgado knows his stuff. I will readily admit that I have a sentimental and an inflexible image of PWK being the eternal horn man, where he was actually the low distortion high efficiency man. I have no doubt he would adopt any tech that would help him reach those goals better or more easily. But still, I wonder why Delgado took the updated Klipsch corner horn, the Jubilee, and made it shorter, with a lower expansion rate, and pulled it away from the corner.

 

[freddi]

100+ % with regards to PWK as being "THE MAN" (and a good one at that besides his brains). The new flagship is horn to 85Hz of so as described by Art Welter. The short horn helps time alignment and a 20Hz 1/4 wave device in such a relatively small package might be a can of worms - painting one to the inside of a corner (pun kinda intended) vs the hybrid reflex/horn approach.

Being free standing allows more placement options and probably a wider audience of buyers. Tho "pricey" - (are they $36k/pair?) they look to offer better value than some $$$$" high end" speakers.

Someone good with hornresp and a table saw should be able to make either a throat ported or external to world ported horn with PRV's rectangular horn and $60 driver plus their $50 round tweeter for less than 1K a pair and get some decent sound down to 30Hz - maybe 20 if they think about it before making a plan.

The way I look at things for a fixed bulk = 6 of one / half dozen of another. There's only so much that can be done but different ways to do it and some may work better to one's goals than others.

 

[freddi]

re😛PWK - I've enjoyed his Heritage line of exponential horns and have heard "music" from K700 and K400 for many years - plus I have two K260 and one K600 - the latter I hope to use with my baby "Belle" before I pass away. (its sat for 4+ years since I was hospitalized for reaction to lisinopril which put me on a ventilator for 9 days and in the hospital a month - the trach operation ruined my vocal chords so I have to push air out to make speech - good thing I didn't have a good singing voice ;^) I've been separated from all my toys since Thanksgiving 2019 when I went to ER - my income in the last year has dropped 60% - so will have zero income soon when I can't pay high WV taxes. My income is from natural gas wells - 37 or so and each has been paying about one dollar per day per well and that is dropping, Thieves got a lot of my stuff - but O hoarded a lot of stuff that survived - they did get 3 out of 4 15" NOS B&C high power woofers, guitars, a hand made fretless bass made by a friend as a gift, tvs, receiver, pc parts with my replacement motors for VPI and AR tables. The worst part about that bad day in 2019 was that a beautiful white feral cat which I knew only two weeks was run over by a car - I still cry other that one.

 

[anatech]

Hi freddi,
I feel for you. On one should ever go through all that.

You are bang on as to why the bins were redesigned to be able to go anywhere in a room (within reason). Being forced into corners probably blocked a lot of sales in the past.

 

[grindstone]

...

I have a question = does the following model using an "R-J" show one way (perhaps very limited) of modeling a throat vented horn? Does it look legit?

TH1 seems one segment short and PH1 is...maybe applicable (???).

 

[grindstone]

OK, perhaps this is more intelligible (first try at lemon). H1 gets thrown away (in Jube or here), but, unlike the Jube with big throat St > Sd, the TH1 runs out of sections before you can tack-on a horn. If the actual throat chamber disappears, then it can be like David's Jube model and the TH1 works as long as we throw away at least H1, and maybe H1 & H2. I think 🙂

 

[freddi]

I'll have to look at your input screem and give that a run - cool.

Is there a hornresp file or port $ with David's Jube model?

my method gets response and fb ~"right" - it could be fun to make an R-J with swapable aperture plate -and have the sub-baffle which holds the speaker - removable.

 

[grindstone]

OK then your method wins -- mine is ghastly but it's also untethered to actual lemon geometry (swagged '55 BBC report dims--lots of RJ geometries over the years). Could (should?) arguably use the TC fields in HR model, too, then H2 becomes just the little 1.91 long stepped piece in front of the cone region. Maybe (?) captures another resonance...too late for that kind of thinking, here.

Probably digressing excessively in RJ-detour (if you start a thread somewhere, I'll pile-in).

For Jube link, see 2nd link in post #16 in this thread.

 

[freddi]

mine might win for making R-J vented box speakers - but can it work for throat vented horn? there's a leftover section which can be used - - but....

I do think the DIY-er with understanding and perhaps $1000 to spend on a pair of horns coud come up with something pleasing and at least competitive with some Klipsch products. IF thre's an inexpesnsive and quite EQ solution. (Abrowser parametric EQ extension could work for Youtube)

 

[freddi]

Does "THIS" make sense ?

 

[grindstone]

My hunch is that expectations are spoiled by what an SP15 did out of the RJ. I think it's the same old problem of a midhorn and 15 needing to meet where both aren't horrible (if present at all). IMO, this is where Wayne has it figured-out--use an economical coner down to a shallow 2-300-ish and let a short-path bass bin (pointed backwards into a corner, loc within 1/4WL & also shallow on top) and the coner midhorn muck-up each other in the modal stuff. Roy solves it with kilobuck horn and kilobuck driver plus electronics--so there goes cheap 🙂 I think if a throat-ported stubby ducted thing makes any sense, it needs to not play high...and might as well be closer to the stubby-ducted EV corner stuff after PWK's permission disappeared (Pat700/800, Geo400, etc). If the bin can stay small, then the extra damping (load) of the RJ-type stuff might make sense. If you look at those BBC tests of the RJ's, they're worse the K's--they get the "W" plus two deep notches. I think they're only usable below the "W". Your SP15 curve is infinitely better. Look--I love phenolic mids as much as anybody, but it's a bugger getting 200 or 300 outta anything economically accessible these years (formerly "racetrack horns")--and it's not a very nice 300 (and you need more than one). OTOH, you're rolling so I say keep going--a man must obey the muse 🙂 Dig-up those BBC RJ reports if you don't already have them and take a look or PM me and I can send them.

 

[grindstone]

Does "THIS" make sense ?

Yes. That looks really representative below 1k. Nice work!

(Missed your post while I was typing).

 

[freddi]

maybe Wayne / "Pi" had a pretty good compromise overall - at least not terribly difficult to build. A peav ey FH1 sitting on a 2 cubic foot ported bass is a way to have a hybrid horn - it pretty smooth and woul d meet the cheap PRV driver/18x10 horn well enough.

Roy has really done great work.

I've seen the BBC reports and used to have 4-=RJ vented 18" driver cabinets 2 a 6.4CF - 2 at 8.2CF.. With a hot on top driver, a diffraction slot such as JBL's would be fun. Evan an oval

FWIW I think the extended RJ model might be good enough to make some rough estimates - I'll compare it to a parallel vented case with same driver, tuning and vent area..


If you see - or make a throat-vented model for the flagship Jube - let me know as that would be fun to play with.
(Did David publish one ? - i lost track as went to that hospital around that time for surgery - or something)

 

[grindstone]

Agreed that it's usable and again good work. And the way you're working, nothing but rear-chamber content needs to turn any corners, so you could try to play high enough to meet the phenolic midhorn--AND stay economical. I can't guess where the slot starts lowpassing from the inertance.

If I keep playing with my other approach, the port has to be very restrictive (too-much IMO) to get everything to behave and stick a little snorkel on there for better coupling. Might as well just overdamp a little reflex box with a tiny vent and save a few resonances, etc. I'll keep poking at it as thoughts and time allow, hopefully you can do the same.

Oh--and look at the second link in post 16 for Davids model.

 

[freddi]

I had the slot set around the size of a 12" speaker's cone area - can be set up - down

Here's the effect of a pretty large horn stuck in front of a ~stock RJ

It appears to mass load the port and shove tuning lower - but excursion seem to be up
around 60Hz. - The horn does kick in above 100Hz.

I can barely see my monitor -not helped by blood sugar 4x higher than good