Jordan with a Ribbon MLTL

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I started down the JX92S minimonitor route more than five years ago. A couple of years back I developed a Jordan JX92S crossed to a ribbon tweeter which received very good comments from listeners.

Recently I built a MLTL which incorporates the Jordan JX92S and Aurum Cantus G2si ribbon as drivers. The MLTL is a slight modification of GM's 48" design. This design marries the exceptional performance of the JX92S with a high quality ribbon as used earlier in my mini-monitor design. The MLTL achieves a lower F3 point (I'm getting below 40 Hz in my measurements) than the mini-monitor could do. The sound is very nice indeed as you have the enough bass impact to satisfy most people yet a very petite size enclosure. My unit (see picture) is constructed from solid cherry side cheeks and MDF. I used Martin King's spread sheets to slight reduce the internal height to 46"and to optimize the port tube length vs. Greg's design. The external box dimensions are 7.5" W x 6.5" D x 47.5" H so the overall package is relatively small for a floor standing speaker.

I also included an external switch to permit me to use either the crossover network between the JX92S and the G2si or alternately to just use the JX92S full range with a baffle step compensation circuit. Thus one can compare the full range driver performance vs. the crossed over version very easily!

I'm thrilled at the performance of this speaker as it handles most material with ease. While it may not suit a hard rocker, it will satisfy a lot of listeners.

Jim
 

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Jim Griffin said:
Recently I built a MLTL which incorporates the Jordan JX92S and Aurum Cantus G2si ribbon as drivers. The MLTL is a slight modification of GM's 48" design.

Hi Jim

I also went from your JX92S mini monitor to GM's 48" MLTL design with a ribbon added - in my case a Fountek JP3, which is not quite as refined as the Aurum Cantus model I’ve heard. I kept the length and Cross Sectional area of GM’s design but used a pentagonal cabinet of MDF. This shape produces a very narrow baffle with no parallel internal sides. Building it was "interesting" to say the least.

My xover is still under development (ie I’m using it but am not entirely happy with it). When I get round to finishing a test mike kit, I will be trying to bi-amp, rolling off the Jordans with a passive line level at about 6k and using a 2nd order high pass crossover network on the Fountek. I don’t want to run the ribbon without a protective cap in series and this seems the best compromise.

I’d be very interested to see details of your xover and any changes you made to the port.
 
opinion on full range vs tweeter in

Jim,

Very nice design and execution. I am using jordans in a backhorn full range with a supertweeter coming in around 16K. Very nice driver. Can you comment on the differences that you hear between running your MLTL's full range and with the crossover in ?

PJN
 
Comments on questions:

1. "PS... do the better TB's sound close to the Jordan's or do the Jordan's wipe the mat with them?"

None of the Tang Bands 4" drivers are in the same league as the Jordan X92S. The CSS FR125S driver is a closer contender if cost is prime concern but I still like the Hordan from a performance viewpoint.

2. "Wonder how this would sound compared to the Jordan BIB?"

This MLTL is very easy to build. If your linked design and plot are typical of the Jordan BIB simulation, one needs to compare that to the attached. The Jordan BIB appears to be very rough and flawed in my opinion vs. the MLTL.

3. "I'd be very interested to see details of your xover and any changes you made to the port."

The port change is to length it 0.25" vs. GM's original design to account for the shorter length of the line (48 to 46").

The crossover is at 3000 Hz which is superior as it better matches the power response of the Jordan to the ribbon. The Jordan starts to beam a bit above 3000 Hz. On axis the ribbon's upper octave (10-20 kHz) is flatter and more extended vs. the Jordan's upper end response.

The Jordan with a ribbon crossover for the mini-monitor version of this speaker was on the CSS website for the last 18 months but they have recently removed it for some reason. That crossover is a good starting point for the new MLTL design.

4. "Can you comment on the differences that you hear between running your MLTL's full range and with the crossover in ?"

Overall the sound is much as I found with the Jordan JX92S mini-monitor vs the addition of the ribbon to it. The crossovered design with the ribbon certainly has more sparkle and sounds better to me vs. running the Jordan full range. I could live with the full range version but if you ever heard the ribbon version, you would want it.

The main difference between the minimonitor and the MLTL is that you'll not wish for a subwoofer for most music with the MLTL. It is much more complete sounding speaker.

Jim
 

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Here's the crossover. I also have the complete file from CSS as a 180k PDF and can email it to you if you want to contact me at

colin(usual symbol)shelbourn(dot)com

If Jim agrees, I could see if I can persuade Ted to put the PDF on his site, as he seems to be building up a number of links to designs using his drivers.
 

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MLTL Crossover Network and More Enclosure Details

Thanks Colin for the thumbnail of the crossover. For the Aurum Cantus G2si I recommend that you use a 3 ohms resistor in parallel with the tweeter. I developed the crossover for both the G2si (commonly available) and the G2i (an OEM version) tweeters which differ slightly in their SPL so the only difference was the resistor value.

Nardis: Yes, the 1.5 mH inductor value is correct. This crossover network incorporates baffle step compensation so you use a higher value than you would normally think.

I should add that I strongly suggest that the same baffle width be used for the MLTL as I used for mini-monitor. The crossover network was developed for that specific baffle width so a wider baffle would necessitate a network change. The mini-monitor had a 7.5" wide baffle dimension so I adjusted the MLTL enclosure depth to achieve the same cross-sectional area of the MLTL as GM's original design. For my version the outside dimensions are 7.5" wide by 6.375" depth by 48" height. With 0.75" thick material for all panels the internal cross-sectional area is 6" wide by 4.875" deep. I'm using a 2.0625" diameter port tube cut to 3" length in my version.

Jim
 
Thx u jim n colin :)

I am thinking of integrating ur design to the car, would there be any changes to the xo network, if i keep the baffle width to 7.5"? considering that i couldnt get a perfect 'box' shape in the car environment, would it matters if i keep the internal volume the same as ur original design? hence theoreticaly the port size and length would still be the same.

thx u for ur help

Ricky
 
Colin said:
Depending on the amount of dB you require in a car, you might find the Jordan JXR6 a better bet - it requires a 1 to 4 litre sealed box and is both smoother and less directional than the JX92, so requirement for tweeter is less. Probably easier to fit in the available space, too.


There used to be a JX62, wonder what happend to those?
 
Colin said:
The 62 was Ted's earlier attempt to get much lower LF out of a JX53 (I think it developed out of a project for a client). The JXR6 does it much better and goes farther into the HF.

It would be interesting to see if something like a JX62 can still get the high frequency JXr6 has. I think the success with the JXr6 is that it not only has a good FR, but also rolls off at a good slope. This is really critical for detail. The other advantage is it has very good spectral decay characteristics, expecially in the first 0.36ms. A good indication of accurate reporduction of music.
 
soongsc said:


It would be interesting to see if something like a JX62 can still get the high frequency JXr6 has. I think the success with the JXr6 is that it not only has a good FR, but also rolls off at a good slope. This is really critical for detail. The other advantage is it has very good spectral decay characteristics, expecially in the first 0.36ms. A good indication of accurate reporduction of music.


If anyone has some JX62 for sale, I would be interested.
 
Re: MLTL Crossover Network and More Enclosure Details

The crossover network was developed for that specific baffle width so a wider baffle would necessitate a network change. The mini-monitor had a 7.5" wide baffle dimension so I adjusted the MLTL enclosure depth to achieve the same cross-sectional area of the MLTL as GM's original design. For my version the outside dimensions are 7.5" wide by 6.375" depth by 48" height. With 0.75" thick material for all panels the internal cross-sectional area is 6" wide by 4.875" deep. I'm using a 2.0625" diameter port tube cut to 3" length in my version.

Jim

Dear Jim, lokking at the MLTL-48 where the JX92S located centred 15.46" (39.3cm) from top. How did you locate the Ribbon tweeter and the JX92 measured from the top?

From my previous experience, the small mini monitor excel at the significant decrease in cabinet coloration compared to larger floorstander not to mention better imaging. Do you agree that your version of Ribbon tweeter+JX92 in MLTL suffer from the same problem compared to the minimonitor?
 
Irwanjf,

The Jordan JX92S is located exactly the same as in the original MLTL design (15.46" down). The ribbon is then placed so that its flange and the JX92S flange are 0.25" apart. This works out to be about ear level for a listener who is sitting.

Floor standing cabinets need to be braced internally to reduce any panel colorations. This effect is of much concern for larger floor standing speakers. I use a windowed brace every 12 to 18" apart in my designs. Another saving grace for this MLTL is that the cross sectional area of the 'pipe' is relatively small. Hence, the sides are close together so colorations are reduced even more. My speakers don't have noticeable colorations due to panel rigidity.

Jim
 
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