15" Jubilee Design

[down_2_earth]

why would anyone think they can just step in and change the sizes of the cabinets and expect the speakers to work correctly.

Because we have several things at our disposal that were not availble cheaply 30 years ago. We now have the equivalent of $20,000 worth of test gear for less than $500. REW and other software is free, as is Hornresp. We have a solid base of Do It Yourself fanatics with great knowledge and skill who are willing to share openly, that's why. Any other questions, hombre?

you missed the point of the partial post you quoted.

[ClaudeJ1]

That's a very interseting idea, but there is a problem in your illustration. First, I'm no expert and someone please correct me if I'm wrong but I believe your addition to the front horn element will interact with the wave in very strange ways creating nonuniform directivity and many other problems. Second, your illustration is a modification of an already modified design:

JWC has built and owned more bass horns than anyone here except Roy Delgado. His mod would work as far as I can tell, and could easily be simulated in Hornresp or AKABAK. As to the directivity paranoia, you could make it a full triangle and come to a point, which was suggested by Roy Delgado, who did most of the grunt design work on the original Jubilee anyhow. He's the one who splayed the horns and got it to work up past 1 Khz. which is what Paul Klipsch WANTED, but didn't do himself. Roy solved the puzzle and he suggested the mouth extension on the Jube. The Jubilee perfoms so will with 12" drivers, why bother with 15's for a home application? You would be better off just extending the horn to make it longer with a bigger mouth as suggested by the original designer, Klipsch's Chief Engineer of Pro Products.

IMHO, there are lots of wrongs trees where we can all bark, and this 15" business is one of them. Two 12's is already better than a single 15" which is plenty already. Personally, I wouldn't waste the time or lumber without a good simulation first. I have measured several real Jubes and their clones and NONE of them have pretty curves without PEQ anyhow.

Edited May 12, 2014 by ClaudeJ1

[ClaudeJ1]

Yep. Way easier too. I only wish the horn path was longer on it.

jc

Any chance of modifying the Jamboree to make the volume what you wish? I'd love to hear more on that.

I'm not concerned with the woofer chamber volume......just path length. I'm not saying this is a problem....just something I would want. The Jube path is 55"...the Jamboree I think about 40". Khorn is greater than 55" if I remember. I drew up a basshorn with the footprint of an MWM but 1/4th space instead of 1/2 space.......I didn't have the guts to build it.

You want to extend the length of the Jamboree.....then you are now at a depth of a 30" plus cabinet. The Jamboree is good. I'm just speaking in principles depending on what you want. Heck....build a straight axis bass horn and go two way with a tap horn sub..... Then this whole subject really becomes academic.

challenge to the group....

Come up with a 38-40Hz 1/8 space bass horn with the footprint of the khorn or jube with a path length of 55" or better......with the goal to get out to 400Hz plus......That is where it gets hard.....real hard....

jc

Amen brother James. I didn't read this before I wrote mine, but we are saying the same thing in a different manner.

Edited May 12, 2014 by ClaudeJ1

[ClaudeJ1]

Personally, before I would start a Jamboree project I would want to have a look at some measures of freq response & efficiency/distortion. It may be a fine cabinet, but there are some unknowns (eg. does it go high enough so that it can be used in a two way system - if that is important ...).

Starting from scratch is always a possibility, but we know that the Jubilee works. So that always makes it a good starting point.

Has the OP had an opportunity to hear a Jubilee? I have a garage built version (a faithful rendering IMHO) and I think it sounds pretty darn good ... even if it only has 12 inch drivers.

My Jamboree simulation in Hornresp shows it to be very smooth and it goes pretty high with an Eminence Kappa 15C (on of the best drivers out there for the money IMHO). The 15C (black line), overall is a better driver for the Jamboree than a K-33, both shown with corner loading, which drops the low end by about 30 Hz vs half space simulation. The plans from the designer, Dana Moore, are available for purchase at http://www.soniphase.com/

Edited May 12, 2014 by ClaudeJ1

[ClaudeJ1]

Personally, if I were to go through the trouble of building a Jamboree, I would do it in halves, with a single 15 per half. It's probably the only thing I would consider to replace my Quarter Pie horn if I absolutely needed to save the floor space. It would only be 3 1/4 inches "taller" than my 17" tall, low profile, Quarter Pies, and go low enough with compulsory corner placement to match my amazing Danley DTS-10 Super Subs (or the new Klipsch 1802 if you prefer). With a single "half J2" bin you would be able to cross at 600 Hz. to a Klipsch K-402 horn at 600 hz. where it still maintains perfect polars/pattern control, and allow amazing 2-way perfomance with a Berrylium 2" driver. That would then be the most compact, a$$ kicking system on the planet for 2.1 with 10 Hz. to 20 Khz. performance at high SPL and super low distortion in fully horn loaded top to bottom in the most compact space possible. Great compromise.

Edited May 12, 2014 by ClaudeJ1

[NBPK402]

Personally, if I were to go through the trouble of building a Jamboree, I would do it in halves, with a single 15 per half. It's probably the only thing I would consider to replace my Quarter Pie horn if I absolutely needed to save the floor space. It would only be 3 1/4 inches "taller" than my 17" tall, low profile, Quarter Pies, and go low enough with compulsory corner placement to match my amazing Danley DTS-10 Super Subs (or the new Klipsch 1802 if you prefer). With a single "half J2" bin you would be able to cross at 600 Hz. to a Klipsch K-402 horn at 600 hz. where it still maintains perfect polars/pattern control, and allow amazing 2-way perfomance with a Berrylium 2" driver. That would then be the most compact, a$$ kicking system on the planet for 2.1 with 10 Hz. to 20 Khz. performance at high SPL and super low distortion in fully horn loaded top to bottom in the most compact space possible. Great compromise.

I like the idea of cutting one in half...

[Fjd]

My Jamboree simulation in Hornresp shows it to be very smooth and it goes pretty high with an Eminence Kappa 15C (on of the best drivers out there for the money IMHO). The 15C (black line), overall is a better driver for the Jamboree than a K-33, both shown with corner loading, which drops the low end by about 30 Hz vs half space simulation. The plans from the designer, Dana Moore, are available for purchase at http://www.soniphase.com/

JamboreeK33vsKappa15C.jpg

Claude, I've been thinking about the Jamboree build for a while now, and more recently, a build of your Quarter Pie horn since you have done a really nice job showing 'how to.' Thank you for the forum posts. However, now you've got me "jonesing" with a more intense desire (or shall I call it addiction in its infancy?) to start planning something for this summer.

Personally, if I were to go through the trouble of building a Jamboree, I would do it in halves, with a single 15 per half. It's probably the only thing I would consider to replace my Quarter Pie horn if I absolutely needed to save the floor space. It would only be 3 1/4 inches "taller" than my 17" tall, low profile, Quarter Pies, and go low enough with compulsory corner placement to match my amazing Danley DTS-10 Super Subs (or the new Klipsch 1802 if you prefer). With a single "half J2" bin you would be able to cross at 600 Hz. to a Klipsch K-402 horn at 600 hz. where it still maintains perfect polars/pattern control, and allow amazing 2-way perfomance with a Berrylium 2" driver. That would then be the most compact, a$$ kicking system on the planet for 2.1 with 10 Hz. to 20 Khz. performance at high SPL and super low distortion in fully horn loaded top to bottom in the most compact space possible. Great compromise.

If you have the time and are so inclined, can you run the following 15" drivers through the Hornsrep model you have developed for the Jamboree horns and your Quarter Pie horns?

I currently have 4 of the JBL E145 drivers that I have earmarked for the Jamboree horns. I picked up a pair of AE TD15M-4 drivers that I wanted to try in the Khorns, but the Quarter Pie may be more interesting. I wasn't sure how to use the JBL D130 drivers, but I found them cheap during an audio picking excursion.

I also have 4 Altec 416A (the OEM labeled "z") drivers but can't seem to find the specs right now.

Thank you for fueling the addiction.

Edited May 12, 2014 by Fjd

[ClaudeJ1]

"In this day and age, I'd go for a subwoofer rather than hack up a perfectly good horn or make a monstrosity out of it" ------Dana Moore, designer of the Jamboree.

I have taken this route also.

[ClaudeJ1]

why would anyone think they can just step in and change the sizes of the cabinets and expect the speakers to work correctly.

Because we have several things at our disposal that were not availble cheaply 30 years ago. We now have the equivalent of $20,000 worth of test gear for less than $500. REW and other software is free, as is Hornresp. We have a solid base of Do It Yourself fanatics with great knowledge and skill who are willing to share openly, that's why. Any other questions, hombre?

you missed the point of the partial post you quoted.

Not really, Maybe I'm wrong, but he seemed to be poking fun at Klipsch's apparent production technique called Maximum Material Utilization (which I have always done in my Engineering Career). IOW, minimizing WASTE. That can be a huge part of design consideration whenever making compromises. Intended sarcasm aside, it was a good opportunity for me to establish my own point about the modern DIY landscape. No offense meant.

[ClaudeJ1]

BTW, to those who doubt the "simplistic" abilities of Hornresp, it's strenght lies in getting one "in the ballpark" and providing very useful RELATIVE comparisons, not absolute. Besides there are so many variable in mike positions in room or outdoor measurements, that seems to be a relative thing as well. Even anechoic measurements are mostly relative in their data production, since we listen to speakers in various rooms with all of their complex anomalies.

Hornresp is a great tool for what it assumes (axis symmetrical horns) and does for relative comparisons. Besides, it has saved me a whole bunch of sawdust.

[down_2_earth]

why would anyone think they can just step in and change the sizes of the cabinets and expect the speakers to work correctly.

Because we have several things at our disposal that were not availble cheaply 30 years ago. We now have the equivalent of $20,000 worth of test gear for less than $500. REW and other software is free, as is Hornresp. We have a solid base of Do It Yourself fanatics with great knowledge and skill who are willing to share openly, that's why. Any other questions, hombre?

you missed the point of the partial post you quoted.

Not really, Maybe I'm wrong, but he seemed to be poking fun at Klipsch's apparent production technique called Maximum Material Utilization (which I have always done in my Engineering Career). IOW, minimizing WASTE. That can be a huge part of design consideration whenever making compromises. Intended sarcasm aside, it was a good opportunity for me to establish my own point about the modern DIY landscape. No offense meant.

While understanding Maximum Material Utilization..... the point is these designs are not fragile in that they have to be exactly as they are in current production....a lot of production elements of the design has no bearing on sound and more so on solving how to roll them down the assembly line....take the mysterious design of the sides of the 5 sided dog house in a LaScala....only done so the woofer would fit ...else the sides would obstruct the woofer magnets. Having said that...why botther keeping them in if we are going to redesign into a bigger foot print? If you oversize the cab, then you can go with 4 sided as in the Belle.

Edited May 12, 2014 by down_2_earth

[ClaudeJ1]

If you have the time and are so inclined, can you run the following 15" drivers through the Hornsrep model you have developed for the Jamboree horns and your Quarter Pie horns?

Here's to fueling the fire, so to speak. Since the Jamboree uses tow 8 ohm JBL E145 drivers in parallel, I did the curve with the standard 2.83 volt drive with corner loading (0.5 Pi space). Traditionally, I modeled my Quarter Pies (like the apple desert not the symbol) with 1 Pi space (IOW not in a corner) for all of the curves I published. In order to make the comparison more "apples to apples" I changed the Quarter Pie Model to the same 0.5 Pi space and bumped the voltage to 4 volts to make sure the curves lined up. At the standard 2.83 volts @8 ohm impedance, a single driver draws one watt, but TWO drivers wired in parallel in the Jamboree result in a 2 Watt current draw at 4 ohm impedance. Bumping up the voltage for the SINGLE 8 ohm JBL E145 driver in the Quarter Pie draws the same power as the twins in the Jamboree for the exact output and lines up the curves perfectly. The black one is the Quarter Pie, the gray is the Jamboree. As you can see, they both are 6 db down at 500 Hz. and the Quarter Pie has slightly more bass extension. This is no surprise since we are comparing a 5 foot horn to a 3.5 foot one.

Edited May 12, 2014 by ClaudeJ1

[ClaudeJ1]

While understanding Maximum Material Utilization..... the point is these designs are not fragile in that they have to be exactly as they are in current production....a lot of production elements of the design has no bearing on sound and more so on solving how to roll them down the assembly line....take the mysterious design of the sides of the 5 sided dog house in a LaScala....only done so the woofer would fit ...else the sides would obstruct the woofer magnets. Having said that...why botther keeping them in if we are going to redesign into a bigger foot print? If you oversize the cab, then you can go with 4 sided as in the Belle.

Yep. Agreed, no conflicts here. This is why I preferred the used and ugly beat up black Peavey FH-1 bins to my LaScalas. Better HF response in a more solid, slightly wider, cabinet, with no straight section, you can get dirt cheap when you find them.

Edited May 12, 2014 by ClaudeJ1

[ClaudeJ1]

As an additional exercise, I compared the JBL E145 to the D130. No surprises there, just looking at the specs, I figured the high end would be well extended by the D130, which it was on the Quarter Pie about 6 db down at 900 Hz.. You would expect even more high end extension in the Jamboree which would allow you to use a smaller, cheaper driver and horn on top if you wished (like a 1" instead of 2"). In that case, it's good to slightly over 1 Khz. but not sure about the polar patterns on either one.

Edited May 12, 2014 by ClaudeJ1

[minermark]

I like it.

[Fjd]

As an additional exercise, I compared the JBL E145 to the D130. No surprises there, just looking at the specs, I figured the high end would be well extended by the D130, which it was on the Quarter Pie about 6 db down at 900 Hz.. You would expect even more high end extension in the Jamboree which would allow you to use a smaller, cheaper driver and horn on top if you wished (like a 1" instead of 2"). In that case, it's good to slightly over 1 Khz. but not sure about the polar patterns on either one.

QpieJBLd130vsE145_4volt.jpg

JBLe145JambD130.jpg

Facinating. What does the BL mean in relation to the estimated curve? For example, I noticed that the TD15M-8 has BL of 17 while the TD15M-4 has a BL of 11.81.

In fact, given the phase plug on the driver itself, the TD15M has been measured to have a nice curve out past 1,000 Hz. Would it be too cluttered or could it be layered on top or compared to the Kappa 15C?

It looks like the Kappa 15C would hold its own here too.

Edited May 12, 2014 by Fjd

[ClaudeJ1]

Facinating. What does the BL mean in relation to the estimated curve? For example, I noticed that the TD15M-8 has BL of 17 while the TD15M-4 has a BL of 11.81.

Motor strength. Horsepower. Usually a low Qts is a good indicator on a woofer, which is numerically counter intuitive. Like a car, the acceleration is determined by the horsepower to mass ratio as one major factor (Shelby Cobra anyone?).

When the industry converted to "mud magnets" the pancake ones vs. the old Alnico's you could sort of tell by the magnet size and you still can. Now that we have Neodymiums at twice the strength with 1/10th the size and weight, we can't eyeball it anymore, we have to measure.

Edited May 12, 2014 by ClaudeJ1

[ClaudeJ1]

OK, so here's a full Jamboree Horn curve comparison of a two 15C's in series (4+4=8 ohms) in the gray curve and two TD15Mh-8 in parallel (8/2=4 ohms), the black curve. I increased the drive to 4 Volts on the 15C's to make the power draw of 2 Watts input equal for both. You can see the higher BL product affect the high end more than the bass end. Again this is a relative comparison of a horn model that could be off in it's oversimplification but still serves to tell use the difference between drivers. It would never measure this smooth in the real world below 300 hz between cabinet losses, room gain, and mike position. Either one would cross at 600 Hz. just fine.

Edited May 18, 2014 by ClaudeJ1

[jwc]

On 5/12/2014 at 11:49 AM, ClaudeJ1 said:

My Jamboree simulation in Hornresp shows it to be very smooth and it goes pretty high with an Eminence Kappa 15C (on of the best drivers out there for the money IMHO). The 15C (black line), overall is a better driver for the Jamboree than a K-33, both shown with corner loading, which drops the low end by about 30 Hz vs half space simulation. The plans from the designer, Dana Moore, are available for purchase at http://www.soniphase.com/

Hey guys help me on something.  This is an old thread that I must not have seen the later comments after I posted some stuff in 2014.  I ran across this thread when searching for something else.

 

I used to tool around with Horn resp but gave-up as I didn't feel that it helped me that much when modeling a folded horn that wasn't a sub.

 

Those hornresp curves don't look anything like the frequency response I got from the jamboree (I got no beef with the Jamboree BTW).  What are the limitations known to that software ....if there are any.

[Chris A]

26 minutes ago, jwc said:

Hey guys help me on something...I used to tool around with Horn resp but gave-up as I didn't feel that it helped me that much when modeling a folded horn that wasn't a sub...Those hornresp curves don't look anything like the frequency response I got from the jamboree...  What are the limitations known to that software ....if there are any.

JT,

 

I find the real advantage of Hornresp to be in comparing relative designs, not so much absolute frequency, phase, etc. response.  For that purpose, Hornresp is really good and easy to use relative to boundary element models--BEMs, etc. 

 

The MEH design was fairly easy to model in Hornresp once I figured out the "multiple entry horn wizard" input trick which took a few days of scratching my head.  The results it gave me allowed me to arrive at a viable MEH design on the first try.

 

For folded horn, if you're wanting to understand the effects of fold geometries, you'll probably need to use something like ABEC3.

 

Chris