alternative designs- why go jubilee?

[jwc]

Guys. The points here are interesting. Fine. Let me just just ask it this way.

Why not go Jubilee?

I ask it that way because......as far as "compromise".....there is little with the Jub IMO.

The three that will stand out to some will be 1) cost, 2) won't got down to 20Hz, 3) size.

Let's hear of other argueable compromises and how an available "alternative" would be better.

[D-MAN]

Well, don't stop now! Let's escalate!

The ONLY thing that a 12" has is a higher mass rolloff. It will have MORE distortion down low, as it has to NATURALLY have MORE EXCURSION to accomplish the task of moving x amount of air due to its cone diameter. Excursion is ALWAYS non-linear. Hence, more excursion=more distortion. Doubling drivers reduces excursion, so less distortion naturally results.

As far as 2 -12" moving more air per excursion than a single 15" - granted. But then 2 -15's move more air than 2 - 12's, right? My point.

Actually, the historical documentation prefers 15" as being the best possible choice for a given excursion and the comparitive ratio of mass-to-excursion and the amount of air that the cone grabs is better in a single 15 than a single 12. In particular, Badmaeiff and Davis' "How to Build Speaker Enclosures", from the 60's, amongst others. Actually they say 2-15's are the cat's meow because of the efficiencies acheived for a given excusion and the transient response due to mass rolloff is better than a single 18 which is pretty much inarguable. I'll dig around and see if I can find a reference that shows this and try to post it here, but I can't promise...

In the case of the Jubilee, we are concerned with a 90 sq. in throat (the combined area) compared to the Khorn's 78 sq. in. throat (the narrower slot notwithstanding). That is a total difference of 12 sq. inches. Now do you REALLY think that there is a massive difference there? The answer is NOT!

The real concern is how big is the slot and subsequent channel, which determines the amount of throat distortion you will generate at a given SPL. Which one wins? Probably a wash. The Jubilee, by virtue of dual drivers, which lessens the required excurstion per given SPL would be a lower velocity threw the throat, but this is counteracted by small slots and channels. The Khorn has wider channels - but a narrower slot - which is going to INCREASE reactance initially. This is counteracted by the wider channels, so I figure it's a wash.

We could resolve this by calculating the differences in reactance especially at the throat(s), but that is quite complicated, and I'm not quite sure that the result in acoustic ohms would be in regards to the particular drivers. I do know that the Khorn is operating the K33E under more compression than the Jubilee, though, which lowers its efficiency.

The difference is that the K33E isn't the "strongest" driver. Better ones are available. Why you guys haven't tried them before contemplating "jumping ship" I don't know.

For instance, the Khorn Vb is approximately 3800 cu. inches or slightly under 3 cubic feet. There are a few available drivers that work more-than-satisfactorily in this volume, and can use the throat size (39-78 sq. in). Crossover will require changes, though.

But the point is, you aren't "locked in" to a particular driver with the Khorn like you are with the Jubilee.

The only point of the Jubilee that the Khorn cannot beat is the crossover point itself.

There is only one other design of the same size that I know of that can kick you around AND crossover relatively high compared to the Jubilee and that's mine which uses a single 15 and a 78 sq. in throat!

DM

[Horatio]

Escalate?!??

I don't want to debate this point into the ground, but I suspect my earlier point earlier about dual 12's was misunderstood: of course, a SINGLE 12 will, as you say, NATURALLY have MORE EXCURSION to accomplish the same task as a SINGLE 15. My point is that TWO were used in place of a SINGLE 15. Thus, for similar output, the TWO 12's will have less excursion, collectively, than the SINGLE 15.

I am interested in your comments on the drivers for the Khorn: I've used Speakerlab W1508S, W1504S (long, long time ago), Eminence (can't recall now, something like 151311?), EV15L and K33E's in LaScala-like (own custom design), University Classic and Khorn designs (not all drivers used in all designs). In particular, I found that the Khorn only came alive for the K33E. I'd be REALLY interested in which 15" drivers you were thinking of in that last post.

I am also interested in your speaker design, as you say it crosses higher- that'd be a useful contribution (you probably posted it before, and I just haven't looked). I had been planning to EQ this region.

[jwc]

That is a good arguement.

That is what I was looking for. Limitations of two 12" vs a 15" or dual 15"

Now as far as footprint. You are speaking of alternatives. I think it is possible to achieve a same foot print with two 15" woofers. I have sketched this out and I am getting the feeling that this is what Dana has already done. I know two of the Kappa pro LF's would be good candidates. By all means, I would prefer this if I am going to cross at 600Hz. Two of the right 15" woofers should easily accomplish this.

By all means...I'm not looking for a Khorn vs Jubilee battle. I do think they sound different. I have explained how a Jubilee sounds in past posts and it is a non scientific explanation. It does sound good.

[D-MAN]

JC, I AM indeed looking for a Jubilee "battle of the corners"!

If YOU want to build a pair of V2's to compare against your Jubs, I'll send you the plans!

Or are you holding out for the dual-15's... that won't be a fair fight! Wanna build one (you mean you aren't tired of building things yet?!)

Two reasons for NOT going dual 15's - they are excessively LOUD. The efficiencies achieved are very hard get the top-end to align with. I heard a set of 4 of these "Elephant horns" (pic attached one of my old 1970's horns - still working, too!) single 15's stacked in the 70's and the top-end required 2 mids and several tweeter horns on top. That was (and is) a problem!

Then the BMS 4590 comes along with its 113db sensitivity which is understated IMO... which leads me to doing dual-15 designs with modern small Vas drivers. The future has arrived, kids! what took it so long?!

DM

[jwc]

I am in no way tired of building. Only reason you haven't seen more stuff from me this week is that I have had to help my wife with a Halloween party.

I moved from direct radiator to Bass horn after hearing the Jubilee. That was the reason for the bass horn threads I started. After multiple inputs...as you know...I just built the Jubilee vs some custom job.

Now weird enough, I have chosen the jubilee as my first Bass horn build. Most always stated you need to build a la scala for practice. Heck...I have some of those cutouts around here somewhere for the La Scala 2 which I aborted after the Hope trip.

So yeah.....I scratched up an 18" version and a dual 15 version of the jubilee. Both with a slightly larger throat and lower cutoff. All recalculated to work for the bigger drivers. At this point though...I will probably just build another 12 dually. This one sounds good for such a small footprint.

After that.....I'm game to put something else together.....I'm being serious. I'm a little worked up to for your 3rd patent...want to see it. I also have the cutout to make the 223Hz tractrix wood horn that is supposed to go on top of my jubilee. The thing is....got so many things I would love to try......just don't have all that time. I am definately not bored with it.

I would love to do the V2's maybe at some point. Maybe for myself or for someone else. They are beautiful..........look better than any other bass horn I've seen.

[jwc]

Dana. How tall is your V2...feet and all?

[colterphoto1]

Same thing in THX subs- 2x12 works way better than 1x15 aka RSW15.

The piston area and shorter excursion make enough sense for me. Plus the lighter cone is bound to pick up speed easier, giving quicker attack for those plucked Chris Squire Rickenbacker notes!

M

[D-MAN]

Feet? no feet. Are we talking the same thing here - the V2 is the pic in my avatar. It is a single 15" driver 35Hz bass horn.

The V2 is the same size (more or less) as the Khorn bass bin. It is 32" wide by 39" tall.

I will go as far as to say, "you haven't heard these yet"... I really doubt that the Jubilee's do anything the V2's don't, but I'd have to build a pair of Jubs to be absolutely sure. I already know that they outperform the Khorn bass bin...

I have too many other designs to build first, and 12" drivers don't really interest me at all.

DM

[bodcaw boy]

wow some many things to choose.....where do i start........

It's not the same as saying "I want a smooth response", it goes much further than that, like a "smooth response from here-to-here at nn efficiency", etc. Crossover points, the number of crossover points, the footprint size, the desired sensitivity, the maximum SPL, etc.

amen brother!!

The Khorn can be taken to the maximum performance it is capable of, and few here (if any) have done that, IMO. The Jubilee comes along and is of great interest in the Klipsch-afficianado community. They are DIFFERENT, each has its attributes. One does not "replace" the other by total sonic eclipse! Different set of goals.

actually, they had the same goal. i mean, i only heard paul say it a couple hundred times.........

There is something to be said about the intellectual satisfaction of hearing examples of all of the PWK-designed horns, which I have yet to do. But how much of the Jubilee's apparent appeal is based on that rather than its performance. I figure that a good part is the zeal is based on the PWK effect. But that has nothing to do with the actual horn itself. That is a possitive mindset that the listener brings to the experience, not part of the actual technical performance at all. I can't get over that from the "gushing" that goes on here about the Jubilee. Too much emotional predisposition to be analytical, IMO.

i am sure that some satifaction is based on zeal but only because paul has delivered in the past. i guarantee you that if paul had failed over and over, not much zeal would exist. and if it delivers, IT HAS EVERYTHING TO DO WITH THE HORN!!!! because paul was very very interested in the technical performance of the horn; he took his audience very seriously and did not want to dissappoint. i think the "gushing" comes from listening and listening leads to conviction that maybe paul delivered again.

I for one, do not hold with dual 12" drivers out-doing a good 15". Now we can argue about what constitutes a "good" driver, but why bother? I have my opinion, and that is all it is. Taking it a step further, if 2-12" drivers are good, then 2-15" drivers would be better, right?

gotta tell you, i have heard 12" whip a 15", a 6" whip a ten because the difference in the design and exectution has everything to do with performance. opinions do not constitute fact.

I think the Jubilee is a well-designed horn, but so is the Khorn. I understand the benefits, effects, and drawbacks that each design entails. It is just a matter of choice.

paul thought he could do better than the khorn. that is why he made the jubilee.

When being a horn "consumer" one has to decide what intellectually is appealing about the design, and THEN one tries to hear examples, does one not? The performance tends to reinforce the pre-determined appeal.

i hope that the performance tends to confirm the specification. if not, we missed something.

Where I would be quite interested in hearing a pair of real Jubilees first hand, they would have to totally eclipse all of the corner horns I have heard to date in order to overcome my opinion of 12" drivers, which traditionally serve better as guitar speakers than bass guitar speakers, IMO. Since I doubt that it would be an eclipsing experience, see what I mean? Mindset is paramount.

12" are only for guitar speakers? again, opinions do not constitute fact. well i think horns should only be used for pa......now where have i heard that mindset before.

So if you have already decided, as it were, to search for the elusive "better" speaker, then you are already psychologically set up for the Jubilee as being "better".

well i would hope that technical data had more of an impact than a visit to the shrink. paul was very unique in that respect. he liked "dirty curves";

It probably isn't technically "better" in all that the term could mean, it's probably "different". But when you're primed for "different", there you go!

what if i told you that maybe, just maybe, it was a smidge better technically. naw, it won't matter; already primed..........

DM

[bodcaw boy]

Well, don't stop now! Let's escalate!

okay!!

The ONLY thing that a 12" has is a higher mass rolloff. It will have MORE distortion down low, as it has to NATURALLY have MORE EXCURSION to accomplish the task of moving x amount of air due to its cone diameter. Excursion is ALWAYS non-linear. Hence, more excursion=more distortion. Doubling drivers reduces excursion, so less distortion naturally results.

is there only one formula for a 12"?

As far as 2 -12" moving more air per excursion than a single 15" - granted. But then 2 -15's move more air than 2 - 12's, right? My point.

how about dual 18" or better yet three 12"? we did dual 12" because each 12" had a horn and we just "stacked" one top of each other. there are oh some many more items to consider to help excursion and so many more items to consider other than excursiion...

Actually, the historical documentation prefers 15" as being the best possible choice for a given excursion and the comparitive ratio of mass-to-excursion and the amount of air that the cone grabs is better in a single 15 than a single 12. In particular, Badmaeiff and Davis' "How to Build Speaker Enclosures", from the 60's, amongst others. Actually they say 2-15's are the cat's meow because of the efficiencies acheived for a given excusion and the transient response due to mass rolloff is better than a single 18 which is pretty much inarguable. I'll dig around and see if I can find a reference that shows this and try to post it here, but I can't promise...

again, are there only one formula for a 15"?? never heard of the book but then again never heard of speakers made from using this book. cook books, in my opinion (again this not fact), get you in the ball park because they tend to minimize and trivialize the importance of keeping so many parameters in balance. paul used to tell me that the reason not many people designed horns, much less good horns, because they didn't want to go that extra 20%.

In the case of the Jubilee, we are concerned with a 90 sq. in throat (the combined area) compared to the Khorn's 78 sq. in. throat (the narrower slot notwithstanding). That is a total difference of 12 sq. inches. Now do you REALLY think that there is a massive difference there? The answer is NOT!

slots are not the only thing going on here. how about the design differences in the woofers themselves, the loading of the back air chamber, the path length differences, the discountinuities in the expansion, etc, etc.

The real concern is how big is the slot and subsequent channel, which determines the amount of throat distortion you will generate at a given SPL. Which one wins? Probably a wash. The Jubilee, by virtue of dual drivers, which lessens the required excurstion per given SPL would be a lower velocity threw the throat, but this is counteracted by small slots and channels. The Khorn has wider channels - but a narrower slot - which is going to INCREASE reactance initially. This is counteracted by the wider channels, so I figure it's a wash.

you ought to read the aes paper. distortion reduction was actually quite significant. and it isn't really all that much to do with narrower or wider; area is key.

We could resolve this by calculating the differences in reactance especially at the throat(s), but that is quite complicated, and I'm not quite sure that the result in acoustic ohms would be in regards to the particular drivers. I do know that the Khorn is operating the K33E under more compression than the Jubilee, though, which lowers its efficiency.

actually more compression, increases efficiency until you start to distort the air movement.

The difference is that the K33E isn't the "strongest" driver. Better ones are available. Why you guys haven't tried them before contemplating "jumping ship" I don't know.

better how. pulling out one parameter and upsetting the balancing act and then introducing a different parameter upsets the other parameters. ask those who took a la scala and put a k-43 in. it is a "stronger" driver but only in certain areas. as doc's posts say, it's all about compromise.

The only point of the Jubilee that the Khorn cannot beat is the crossover point itself.

actually, there quite a few others.

DM

in all seriousness dm, thanks for the fun discussion and for making me think!!

berryboy roy

[Coytee]

This continues to be very interesting reading!

(insert face eating popcorn here)

[]

[Duke Spinner]

in RED, no less .......!

[bodcaw boy]

in RED, no less .......!

changed it just for you dukester!!

[Deang]

Shouldn't have changed it -- we could have said, "Words of Roy in Red".

[bodcaw boy]

but blue fits me....

blueberry roy

[Coytee]

BerryBoy... sure seems as though you killed the conversation!

[]

I for one, was looking forward to the continued chat.

[bodcaw boy]

yeah that was not my intent. i sure wish that trey had not put that klipsch logo on my name. i liked it better when no one knew i worked for klipsch.

did you get my answers to your questions? how are those ugly, big, stinking speakers doing? (just in case your wife reads this thread....[])

[colterphoto1]

at least you don't have to use your real name....like other Klipsch employees! []

oh, VERY good stuff above! and I so dig that Roy is now quoting Doc. Can't wait to hang wit youse guys at P7!

M- soon to have a Batman logo of his very own.

[arfandbark]

GO HOGS!!!!!!!!