How bout a Jubilee top?

[Pete H]

here u go

You're right! That top does look better and I would offer my services to do all the testing necessary.[]

[ssctrojan1980]

pete.

Contact Mr. James W Cullison

[ssctrojan1980]

here u go

Here is where you guys get all messed up. See i'm sure that would test well. But whatever curve comes up on a piece of paper will be nothing like the sound of those horns are in person....

[spamhead]

the vtrac has a different size throat and therefore a different set of measurements than the trachorn. both are similar in construction to bruce edgars tractrix horn article in speaker builder magazine in the days of yore.

I am aware of that I also have built 1" and 2" throat trachorn copies after I was unable to purchase them from ALK because of limited availability from Martinelli sound, and you are correct you must use a different flare rate, and I also use Edgars formula for area expansion on those flare rates, what I was stating was that it is obvious that the vtrac is copied from the trachorn I my reasoning is that of all the many many horns and their different flares that resemble each other the vtrac and the trachorn are the only two that really look just about like the same horn basically constructed alike with a little difference in the bracing of the driver and that both by coincidence are an upgrade for the stock khorn hi hat. I for one have no problems with the vtrac, I was aluding to some that they bbq one for one thing and then applaud another for the same.

[Deang]

DeanG,,,,No your not from MO.,,, If you want to read those tech letters you,l have to now get them from our historian JRH,,,, Go fish.

I'd just like to read where The Man used an axe to build 'em.

[Pete H]

pete. Contact Mr. James W Cullison

Thanks, but I really don't know who he is.

[ZAKO]

DeanG,,,,No your not from MO.,,, If you want to read those tech letters you,l have to now get them from our historian JRH,,,, Go fish.

I'd just like to read where The Man used an axe to build 'em.

The tech letter to Ashworth,,dated,,,Nov. 9 1946 refrence to X3. revision.earley work on air chamber

[jwc]

the vtrac has a different size throat and therefore a different set of measurements than the trachorn. both are similar in construction to bruce edgars tractrix horn article in speaker builder magazine in the days of yore.

I am aware of that I also have built 1" and 2" throat trachorn copies after I was unable to purchase them from ALK because of limited availability from Martinelli sound, and you are correct you must use a different flare rate, and I also use Edgars formula for area expansion on those flare rates, what I was stating was that it is obvious that the vtrac is copied from the trachorn I my reasoning is that of all the many many horns and their different flares that resemble each other the vtrac and the trachorn are the only two that really look just about like the same horn basically constructed alike with a little difference in the bracing of the driver and that both by coincidence are an upgrade for the stock khorn hi hat. I for one have no problems with the vtrac, I was aluding to some that they bbq one for one thing and then applaud another for the same.

Spamhead.

The Vtrac from Greg has no gross "copy" of the ALK. It was designed from the ground up to suit his purpose to fit in the Khorn the way he wanted. He knew the max depth of the horn, width and height that he could put in a new baffle that would allow placement of his preferred Beyma tweeter to the side of the midhorn.

With knowing those measurements.....a pure tractrix midhorn was configured. Basically.....a tractrix horn with close to a 2:1 width to height ratio in which the back of the horn and driver wouldn't be "deeper" than a Khorn while the midhorn is paced off centered (like ALK's Trachorn placement).

It just so happened, a 253.5Hz Fc horn would calculate to fit in there and the mouth changed slightly from 2:1 ratio. The expansion for the horn was "similar" to Bruce Edgars described "The Midrange Horn". However....Edgars described way of making a tractrix expansion is inexact. There is a different "trick" involved to make Greg's which I do believe expands with tractrix down to the square mm.

Greg posted how the Vtrac was designed on his website. The only thing similar I see to the trachorn is that his horn is "tractrix" and the build technique/assembly could be the same.

http://www.dcchomes.com/gregstractrixcalculator.html

As you already know, I think, is that these pure tractrix horns sound fantastic for mids. There have been several chit-chatted on the forum. I'm sure they are all similar in Sound....Greg's was designed in the same way but to fit his plan to fit in the Khorn the way he wanted.

jc

l

[Invidiosulus]

the vtrac has a different size throat and therefore a different set of measurements than the trachorn. both are similar in construction to bruce edgars tractrix horn article in speaker builder magazine in the days of yore.

I am aware of that I also have built 1" and 2" throat trachorn copies after I was unable to purchase them from ALK because of limited availability from Martinelli sound, and you are correct you must use a different flare rate, and I also use Edgars formula for area expansion on those flare rates, what I was stating was that it is obvious that the vtrac is copied from the trachorn I my reasoning is that of all the many many horns and their different flares that resemble each other the vtrac and the trachorn are the only two that really look just about like the same horn basically constructed alike with a little difference in the bracing of the driver and that both by coincidence are an upgrade for the stock khorn hi hat. I for one have no problems with the vtrac, I was aluding to some that they bbq one for one thing and then applaud another for the same.

Spamhead.

The Vtrac from Greg has no gross "copy" of the ALK. It was designed from the ground up to suit his purpose to fit in the Khorn the way he wanted. He knew the max depth of the horn, width and height that he could put in a new baffle that would allow placement of his preferred Beyma tweeter to the side of the midhorn.

With knowing those measurements.....a pure tractrix midhorn was configured. Basically.....a tractrix horn with close to a 2:1 width to height ratio in which the back of the horn and driver wouldn't be "deeper" than a Khorn while the midhorn is paced off centered (like ALK's Trachorn placement).

It just so happened, a 253.5Hz Fc horn would calculate to fit in there and the mouth changed slightly from 2:1 ratio. The expansion for the horn was "similar" to Bruce Edgars described "The Midrange Horn". However....Edgars described way of making a tractrix expansion is inexact. There is a different "trick" involved to make Greg's which I do believe expands with tractrix down to the square mm.

Greg posted how the Vtrac was designed on his website. The only thing similar I see to the trachorn is that his horn is "tractrix" and the build technique/assembly could be the same.

http://www.dcchomes.com/gregstractrixcalculator.html

As you already know, I think, is that these pure tractrix horns sound fantastic for mids. There have been several chit-chatted on the forum. I'm sure they are all similar in Sound....Greg's was designed in the same way but to fit his plan to fit in the Khorn the way he wanted.

jc

l

If one works in mm for the entire build process than it is not necessary to take the time to draw out the trapezoid side view and then measure by hand the "longer Marker measurements".

This longer measurement is already specified in two places in Erik's original spreadsheet.

First in the "stretch factor(length of non curved horn sides)" cell which gives the percentage by which to multiply the length of the centerline curve,

Second in the "sidewall(stretched) [mm]" column.

using the sidewall stretched column in conjunction with the height[mm] column will give you the curve needed for the template.

No need to do any additional conversion, measuring, or division.

-Josh

[jwc]

Josh...that is the intent of Volvoteers spread sheet. To make sidewall stretch measurements. I don't trust stuff like that. I use only the tractrix calculator part of his spreadsheet for a quick view of what I'm looking for. I have counterchecked the tractrix calculator by hand.....it is accurate. I have no way to countercheck his "stretch walls". I feel no need to use it. It doesn't speed me up really.

BTW...that wasn't the intention of my post......to explain techniques of a build...mine was to address the notion of Greg copying the Vtrac...which he didn't.

jc

[Invidiosulus]

The stretch factor is merely the length of the top and bottom expressed as a percentage of the length of the horn along the center line.

Not sure what else about it would need counterchecking.

I don't want this to seem argumentative.

I'm truly curious what might be wrong with doing it as described above.

-josh

[jwc]

Josh. I don't disagree with you on anything. I know you know what you are talking about and you do great work too. I only brought up that techno babble just to explain how the Vtrac was brought up from scratch....not a copy of the Trachorn. Cool?

So...when are we gonna see some pics about the top hat??? That is what I would like to see.........and just what the heck you put in it.....

That is the real thrill of the thread.

jc

[Invidiosulus]

Mea culpa.

Sorry for the hijack.

I'd love to see some more pics as well.

-JPB

[ssctrojan1980]

Here is a pic with frames. I took it before packaging and shipping Friday.

[spamhead]

the vtrac has a different size throat and therefore a different set of measurements than the trachorn. both are similar in construction to bruce edgars tractrix horn article in speaker builder magazine in the days of yore.

I am aware of that I also have built 1" and 2" throat trachorn copies after I was unable to purchase them from ALK because of limited availability from Martinelli sound, and you are correct you must use a different flare rate, and I also use Edgars formula for area expansion on those flare rates, what I was stating was that it is obvious that the vtrac is copied from the trachorn I my reasoning is that of all the many many horns and their different flares that resemble each other the vtrac and the trachorn are the only two that really look just about like the same horn basically constructed alike with a little difference in the bracing of the driver and that both by coincidence are an upgrade for the stock khorn hi hat. I for one have no problems with the vtrac, I was aluding to some that they bbq one for one thing and then applaud another for the same.

Spamhead.

The Vtrac from Greg has no gross "copy" of the ALK. It was designed from the ground up to suit his purpose to fit in the Khorn the way he wanted. He knew the max depth of the horn, width and height that he could put in a new baffle that would allow placement of his preferred Beyma tweeter to the side of the midhorn.

With knowing those measurements.....a pure tractrix midhorn was configured. Basically.....a tractrix horn with close to a 2:1 width to height ratio in which the back of the horn and driver wouldn't be "deeper" than a Khorn while the midhorn is paced off centered (like ALK's Trachorn placement).

It just so happened, a 253.5Hz Fc horn would calculate to fit in there and the mouth changed slightly from 2:1 ratio. The expansion for the horn was "similar" to Bruce Edgars described "The Midrange Horn". However....Edgars described way of making a tractrix expansion is inexact. There is a different "trick" involved to make Greg's which I do believe expands with tractrix down to the square mm.

Greg posted how the Vtrac was designed on his website. The only thing similar I see to the trachorn is that his horn is "tractrix" and the build technique/assembly could be the same.

http://www.dcchomes.com/gregstractrixcalculator.html

As you already know, I think, is that these pure tractrix horns sound fantastic for mids. There have been several chit-chatted on the forum. I'm sure they are all similar in Sound....Greg's was designed in the same way but to fit his plan to fit in the Khorn the way he wanted.

jc

l

JC the question I ask is did Greg design that horn having never seen the alk trachorn? If so then I am incorect saying that it is a copy, however I have a hard time believing this. I took Edgars formula and looked at others and when I made the horns they ended up looking just like a trachorn, both the one and two inch models, my two inch looks closer to the vtrac and the one inch a little more like the trachorn. Now I didn't have a trachorn to measure and mic it but in my opinion my tractrix horns are still trachorn copies because the thought or inspiration came from seeing one before I built it. If the vtrac was envisioned and designed from the beginning to make an alternative for the khorn high hat and he had never seen the trachorn then you could call it origional otherwise it is in one way or another a copy.

[Nat Denkin]

I have been using the ALK trachorn for about two years and it is wonderful. The tractrix in one form or another has been around for about the last 80 years, whether square, round, or rectangular cross section. Limiting to the tophat dimensions is going to impose a lot of similarity as well as having to mate with standard drivers. In the meantime, does anyone have current recommendations for currently available dirviers for a DIY Jubilee base section?

Thanks,

nat

[Invidiosulus]

These have been mentioned,

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-590

Or finding a beat up pair of KLF-30's with the woofers intact.

-Josh

[jwc]

I haven't heard them....but I do think from a T/S spec that they would work...

as posted above..

Eminence Kappalite 3012LF Neo 12" Driver

jc

[jwc]

BTW...those jubelike clones look amzing. Would love to see one in veneer....although most every speaker I've had has been black.

jc

[Pete H]

BTW...those jubelike clones look amzing. Would love to see one in veneer....although most every speaker I've had has been black.

jc

I thought that there was a build thread on here last summer that was a jube that was finished with an exotic veneer???????