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Al Klappenberger

A time-aligned top end - Part II

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Guest David H

Or DIY JUB? tony

I think this horn is going to work well with the Jubilee, we'll know more soon enough. Beauty of the Jubilee, is not having to cross down at 400hz this opens the door to a much larger selection of capable drivers.

Currently there is one set of Eliptrac 400's being tested, I am shipping the second set out next week.

In the search for possible Drivers for use with the Eliptracs, I have run across a few I think might work well 2-way.

1. JBL 2446 500-20k..................$527ea Tried and true driver $$$ [:o]

2. P-Audio BMD-750 500-18K $189ea Reviewed by many, is said to require lots of EQ for 2-way [:S]

3. Selenium D-408Ti 400-20k $240ea Graph looks promising, few reviews [:$]

4. Radian 760NEO 500-20k $299ea Graph looks promising. [:P]

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Guest David H

BTW, I didn't forget about the GPA 1.4 inch drivers, just starting with the 2 inch.

Dave

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Well, now you guys are talking about Jubilees and this is a topic near and dear to my heart.

If this thread were in the Garage Sale forum, I would not make any comments. However, you have put it in the Updates and Mods forum, so comments are fair game.

This would not be a good horn for the Jubilee. The preferred horns for the Jubilee are the K-402 (the big guy) and K-510 (its little brother). These horns are not tractrix but rather a modified (and propriatary) geometry. The modification has the important feature that the horn is CD (constant directivity/dispersion). In simple terms this means that the freq response off-axis is comparable to the FR measured on-axis (IOW, they do not beam at high freqeuncies). They also have a good control of the dispersion. There are several consequences to this. One is the sound (there is a good discussion of this in the work by Floyd Toole), the other consequence is that ALK crossovers are not appropriate (CD horns require a form of equalization). Another point is that although you can cross a Jub bass bin at a higher frequency (higher than 400-500 Hz), there are reasons you may not want to (that is another discussion).

As far as it being a good candidate for other systems ..... I don't know. However, I would suggest that before someone goes down this road you do some research first about 1) matching polars (dispersion) between the drivers at the crossover point (good article by Eargle, Keele and Smith on this topic), and 2) the benefits of using CD horns (many articles by Toole, Geddes and others).

The above posters have shown some fine craftsmanship on their projects and I don't mean to be a wet blanket. Again, if this was in the Garage Sale forum, I would keep my comments to myself.

-Tom

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"In the search for possible Drivers for use with the Eliptracs, I have run across a few I think might work well 2-way."

I'm still very happy with the Peavey 44Xt run two way with the K510.

Shawn

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Guest David H

I'm still very happy with the Peavey 44Xt run two way with the K510.

Sean, I was curious about that drivers as well, thanks I will add to my list of possibilities.

Dave.

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Dave,

With the 4" diaphragm and its power handling I think it would have no problem at all going to 400hz.

This is the Peavey on the K510 with just the CD compensation top end at 10kHz...

DSCN0003.JPG

Scale out to 20kHz...

DSCN0004.JPG

These are linear scaled above so from 10kHz to 20kHz is half the screen. In other words those two notches up high are around 1/10 of an octave wide... very narrow and IME nothing to worry about. The Peavey has a better top end then the Altec 288s I had before it.


Shawn

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Guest David H

Well, now you guys are talking about Jubilees and this is a topic near and dear to my heart.

If this thread were in the Garage Sale forum, I would not make any comments. However, you have put it in the Updates and Mods forum, so comments are fair game.

This would not be a good horn for the Jubilee. The preferred horns for the Jubilee are the K-402 (the big guy) and K-510 (its little brother). These horns are not tractrix but rather a modified (and propriatary) geometry. The modification has the important feature that the horn is CD (constant directivity/dispersion). In simple terms this means that the freq response off-axis is comparable to the FR measured on-axis (IOW, they do not beam at high freqeuncies). They also have a good control of the dispersion. There are several consequences to this. One is the sound (there is a good discussion of this in the work by Floyd Toole), the other consequence is that ALK crossovers are not appropriate (CD horns require a form of equalization). Another point is that although you can cross a Jub bass bin at a higher frequency (higher than 400-500 Hz), there are reasons you may not want to (that is another discussion).

As far as it being a good candidate for other systems ..... I don't know. However, I would suggest that before someone goes down this road you do some research first about 1) matching polars (dispersion) between the drivers at the crossover point (good article by Eargle, Keele and Smith on this topic), and 2) the benefits of using CD horns (many articles by Toole, Geddes and others).

The above posters have shown some fine craftsmanship on their projects and I don't mean to be a wet blanket. Again, if this was in the Garage Sale forum, I would keep my comments to myself.

-Tom

Tom, your comments are always welcome, however your blanket statement about horns and crossover was unwarranted.

First: These horns are in testing, none have been sold. However the initial tests show potential for 2-way operation.

Second: ALK did not build nor offer to build a crossover for the Jubilee anywhere in this thread, I think you are reading too far into this.

Last: A formum member suggested this horn might work well for a Jubilee, I replied that I think it might. I was not aware that the K-402

and the K-510 only 2 horns made that could possibly work with a Jubilee.

Dave Harris

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Guest David H

The Peavey appears to have good potential, thanks for sharing your findings.

Dave

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".....

Last: A formum member suggested this horn might work well for a Jubilee, I replied that I think it might. I was not aware that the K-402

and the K-510 only 2 horns made that could possibly work with a Jubilee.

Dave Harris"

All sorts of horns could be sucessfully used on a Jubilee. There are reasons a CD horn is preferred. If someone wanted to explore CD horns, I would suggest looking at the Klipsch offerings (K-402 & K-510), offerings from Altec (old Altec, the Manta Ray series 2), from Elecrovoice (eg, HP 940 or HP 640), JBL also has candidates (some of their bi-radial series), and Geddes has his Oblate Speroid horns that might be good, Peavy Quad Throat would also be a possibility.

There is a design issue that is important. Others, well before me, have argued about the advantages of CD disppersion and also about setting a crossover point where the drivers match in dispersion. These are goals that one might want to incorporate in the design of their modifications. That suggestion is certainly not "unwaranted". These are design goals that are actually rather common in pro sound.

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Tom,

The Jub woofer is simply a horn loaded woofer. You can stick whatever top end you want on it. If you want a CD top end, do it! I simply don't do the required equalizers. I believe they are best done using active circuits. Passive equalizers just screw things up. Simple equalizers are lossey beasts and screw up the impedance seen by the amp. Constant impedance equalizers have twice the parts and are impractical. This makes my networks fine for either the conventional horns or CD horns. Put an active equalizer upstream from a speaker using a CD horn and a good crossover and you have a much better system than a passive crossover that contains equalizers. Besides, you can adjust a stand-along equalizer to you taste and adjust it anytime you want. A passive needs to be done once and installed in the speaker. It has to be right the first time. From what I have seen from the vast majority of network designs, it won't be!

The Elliptic tractrix is simply another choice, for any speaker. Dave's objective is to choose a good driver for this particular horn, or others. The B&C DCX50 coaxial worked better with this horn than it did with the Bruce Edgar type horns we have been using. The possibilities are simply getting wider, and I think that's good! [<:o)]

Shawn,

It's nice to see the face of your SD380 analyzer. It brings back memoirs! I sold my SD375 on eBay and now have an HP 3563a.

Al K.

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55,

The problem with the 400 Hz crossover for the Belle is the size. It would require raising the top like I had to do to fit the Martinelli Trachorn 400 into the Belle. A smaller horn makes much more sense. The Belle and LaScala woofer has no problem going up to 500 or even higher. Why force a 400 Hz horn into it unless you only wanted to manufacture a single horn for everything. That is what I was doing.

Al K.

my main interst is to use it for the top half of a jubilee. so it does not have to fit anything other that sit on top.

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Or DIY JUB? tony

I think this horn is going to work well with the Jubilee, we'll know more soon enough. Beauty of the Jubilee, is not having to cross down at 400hz this opens the door to a much larger selection of capable drivers.

Currently there is one set of Eliptrac 400's being tested, I am shipping the second set out next week.

In the search for possible Drivers for use with the Eliptracs, I have run across a few I think might work well 2-way.

1. JBL 2446 500-20k..................$527ea Tried and true driver $$$ Surprise

2. P-Audio BMD-750 500-18K $189ea Reviewed by many, is said to require lots of EQ for 2-way Tongue Tied

3. Selenium D-408Ti 400-20k $240ea Graph looks promising, few reviews Embarrassed

4. Radian 760NEO 500-20k $299ea Graph looks promising. Stick out tongue

How about the K-69... or the EV DH1A

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Tom,

The Jub woofer is simply a horn loaded woofer. You can stick whatever top end you want on it. If you want a CD top end, do it! I simply don't do the required equalizers. I believe they are best done using active circuits. Passive equalizers just screw things up. Simple equalizers are lossey beasts and screw up the impedance seen by the amp. Constant impedance equalizers have twice the parts and are impractical. This makes my networks fine for either the conventional horns or CD horns. Put an active equalizer upstream from a speaker using a CD horn and a good crossover and you have a much better system than a passive crossover that contains equalizers. Besides, you can adjust a stand-along equalizer to you taste and adjust it anytime you want. A passive needs to be done once and installed in the speaker. It has to be right the first time. From what I have seen from the vast majority of network designs, it won't be!

The Elliptic tractrix is simply another choice, for any speaker. Dave's objective is to choose a good driver for this particular horn, or others. The B&C DCX50 coaxial worked better with this horn than it did with the Bruce Edgar type horns we have been using. The possibilities are simply getting wider, and I think that's good! Party!!!

........

You are raising the question of "what is a Jubilee". In my book it is more than just a bass bin. .

One view is the "recipie" that was given in the JAES article by Delgado and Klipsch (JAES, 2000). They clearly outlined a 2-way system that used a 2in throat horn for the treble. The same engineer(s) further detailed their thinking in comments related on this forum etc. What emerges was 2-way design that incorporated a CD horn, attention to a crossover point that matched dispersion of the drivers, and perhaps time-alignment etc.

These design goals are not just for the Jubilee, they can be used elsewhere also. Again, I refer to the work of the guys at JBL (JAES article by Eargle et al regarding the 43xx monitor), or at Harman (Toole et al). My view is that it worth some time thinking about overall design goals before someone starts simply swapping parts. If you want to simply swap parts, I have previoulsy listed some CD horns that are readily available on eBay, why not give them a try.

Again, I am not picking on some of the fine craftsmenship that is being shown. But this is a "Updates and mods" section (and not the Garqage Sale section), so I think it is fair to examine these design issues.

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Guest David H

How about the K-69... or the EV DH1A

From what I understand the K-69 and the P-Audio BMD750 is that they are virtually the same driver.

I only listed drivers readily avaialble for retail purchase. Are the EVDH1A avaialbe?

I am sure there are alot of capable drivers I missed, the ones listed are just ones I thought might be capable for 2-way use.

Dave

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Tom,

"You are raising the question of "what is a Jubilee". In my book it is more than just a bass bin."

That's exactly right. I suppose it is what Klipsch says it is! I'm sure Klipsch doesn't care much for what is being done with it by the hackers, but from my point of view, and those of us building clones, it's an improved woofer. That makes the top end just as much a DIY project as a CornScala! How many of use have access to the official design drawings of the Jub bass bin anyhow? How many of them would admit it?

Al K.

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Guest David H

In my book it is more than just a bass bin. .

What is it?

The Jub woofer is simply a horn loaded woofer.

Ok

I think it is fair to examine these design issues.

It certainly is.

I simply thought your blanket statement (This would not be a good horn for a Jubilee) was a bit premature because (although you may be correct) we don't have enough information yet. If you have already done previous testing on a 400hz Eliptical Tractrix I have not heard about, please provide some supporting documentaion of your findings.

I have previoulsy listed some CD horns that are readily available on eBay, why not give them a try.

Once again, are you are saying the only horns that can be used on a Jubilee are CD? If so that seems a bit tunnel vision to me. At one point and time the Earth was known to be flat.

Do you think you could allow me the courtesy to run a few tests before before we condem this horns application possibilities? You are not even giving this horn the oportunity to fail. (you condemed it sight unseen and sound un-heard)

Dave

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In my book it is more than just a bass bin. .

What is it?

The Jub woofer is simply a horn loaded woofer.

Ok

I think it is fair to examine these design issues.

It certainly is.

I simply thought your blanket statement (This would not be a good horn for a Jubilee) was a bit premature because (although you may be correct) we don't have enough information yet. If you have already done previous testing on a 400hz Eliptical Tractrix I have not heard about, please provide some supporting documentaion of your findings.

I have previoulsy listed some CD horns that are readily available on eBay, why not give them a try.

Once again, are you are saying the only horns that can be used on a Jubilee are CD? If so that seems a bit tunnel vision to me. At one point and time the Earth was know to be flat.

Do you think you could allow me the courtesy to run a few tests before before we condem this horns application possibilities? You are even giving this horn the oportunity to fail. (you condemed it sight unseen and sound un-heard)

Dave

Well, Dave some of those quotes you have attributed to me were actually made by ALK. I am not sure where you are headed.

It is not for me to defend whether CD horns are a good idea or not. Others who are more knowlegible have already argued this (I have already given the references). There is already sufficient information on the tractrix horn, and you and ALK already know those data.

I am sure your product is a fine one and I wish you success.

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FYI for anyone interested my memory of what Roy has said in the past about the Jubilee versions that he has presented to us at the pilgrimages and on the Forum was that for him the Jubilee was the LF Horn as designed by PWK and what he presented/demonstrated for us was what Roy Delgado himself (He was not speaking for Klipsch or anyone else but directly pointing out this was his concepts of the best HF Horns/Driver options based on what HF horn/driver designs were currently available from Klipsch) .

Without a doubt PWK fully intended for the Jubilee to be a 2-way design when used in a home enviroment. (see: AES Paper on the Jubilee)

My point of view is if you take a KHorn (or any loudspeaker system) and change any of it's drivers/horns/crossovers from Klipsch's design then it doesn't represent the company's product anymore whether the sound is improved or not by the modifier.

Modifying is fun and a great learning experience in this hobby and I love watching some of the ideas that people try.

I will add one more thing that does bother me and it is the way that modifications are sometimes called upgrades because I believe the word upgrade really should be used to describe any changes done by Klipsch itself.

mike tn

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