Jordan with a Ribbon MLTL

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I'm sure it did Colin- I've used the isodynamic tweeter that was in the Glastonbury and it was only useful down to 4 or 5kHz at best, leaving a nasty raggedy gap in the response when used with a '125. I must admit I'm tempted to get a pair of the new JX125NGs and use them with some Bandor 50mm drivers I have along with my Raal 70-10s above 5 or 6KHz. The Bandors and the Raals sounded really incredible in a lash-up with an active crossover, but couldn't play with any volume if taken low enough to meet the Peerless XLS12 subs I was using. Hardly surprising of course. It's going off topic, but a JX125NG a side in a sealed box would fill the gap in a treat! Rather an elaborate system though...
Back to the new JX125 in an MLTL, if a two-way speaker is wanted and Raals are too costly (and also OEM only in the case of the 70-20s) then perhaps the bigger examples of the newish APR ribbons from Aurum Cantus might do the job down to 2kHz or so, if anyone is selling them yet. Otherwise Nardis you could cram a JX6T in along with your Fountek and cross low to the '125 as Colin suggests. Of course your system already sounds very nice- at least the last time I heard it- but probably could have done with moving a bit more air!
 
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Jim,
Thanks for all the great work on this project. I have built 5 of the mini-monitor, Aurum Cantus ribbons using the Partsexpress boxes for my home theater and love them. I am now on the next phase of building the Jordan/Aurum Cantus MLTL. I have the boxes built. In one of your posts you mention using sonic barrier at the top of the box. Several questions. 1. Why not use it as the sole stuffing material? You use foam for the mini monitors. I'm not sure how this is seen in Martin's spreadsheets. 2. Is there an advantage to using the Sonic Barrier in that it dampens cabinet vibrations, or is this a potential negative? I have both the acousti-stuff and sonic barrier so could use one or other or both. Any thoughts. Thanks again for the great work.
Jack C
 
Jack,

As you have the Sonic Barrier material already, I would suggest that you do add a layer of it inside the top of your boxes. In my experience the top is a high pressure area that benefts from the more robust damping material. But Sonic Barrier is likely too much for a general acoustical material for a MLTL. The foam damping material for the vented mini-monitor is a thinner less lossy material which serves the purpose better for that specific application.

For the rest of your MLTL use Acousta Stuf as your volume filler stuffing from just below the JX92S to the top of the box. From my recent work with other MLTLs I'm of the opinion that you can tailor the amount of this stuffing to adapt the speaker to your room. Consider using a looser fill (more teasing and less material will be looser) if you room is relatively heavy damped in terms of furniture, carpet, draperies, and such. A more dense fill (slight compression of the stuffing when you insert it vs. the aforementioned loose fill) if you have a bright room with reflective floor and little damping in its furnishings. For use in-between these two extremes stuff according between these two levels. The bottom line is that you can adjust your speakers to your environment for better sound vs. a one size fits all kind of adjustment.

Hope that helps you and gives you some ideas about how to improve the in-room performance.

Jim
 
My 48 Jordan MLTLs suffered quite a bit of vibration on the top panel, so the 31 version I'm on with at the moment has a t-brace to reduce this. I'll probably also double up the panel thickness.

I found changing the stuffing made less of an impact, though I was using BAF wadding which is generally thought to be effective from lower mid-range upwards.
 
Port location revisited!

Tom:

Some answers below--

1. The MLTL-48 design on the DIY enclosure designs web site shows the port being in the front, while I believe the picture of your speakers in post #1 of this tread shows your's on the back. Why was this done, and what impact does this have on the design?

I like rear porting vs. front but it should not matter too much. Duke on Audioasylum has some good reasons to rear port at:
Speaker Asylum - Rear port pros and cons (not an unbiased opinion) - Duke - November 18, 2007 at 00:05:36

2. Did you put any bracing in your cabinets? If so, how many, where, and general shape please?

Yes, I use one windowed (single large diameter hole) brace placed a couple of inches below the woofer cutout. This location is a good place to locate a wire grid to hold the loose stuffing in the upper portion of the box as well.

3. On your monitors, you rounded the outer edges of the 7.5 inch wide front baffle at 1/2 or 3/4 inch. Did you also do this with these speakers?

I also rounded the outer edges of the MLTL.

4. Also, what type and amount of "stuffing" did you use, along with where did you locate it ( .54 lbs at the top, as shown in the above link? )?

I filled the top of the box with teased Acousta Suf brand material.

In my speakers I recently noticed that the glue seam at the top of the enclosure had a few small separations to the side panels. This is a high pressure area and the cracks created noticeable air leaks on bass heavy music. I reglued that seam and recalked the inside seams at the top of the box. I also inserted a pad of Sonic Barrier 3/4" thick dampening material into the inside top of the box. I replaced the loose stuffing between that pad and the wire grid located on top of the brace. That mod seems to have solved my issues.

Jim

Mr Griffin,
This is my first post to the forum so greetings to all! My question concerns the vertical position of the vent in your design, it seems a lot closer to the bottom of the cabinet than the design on the Jordan website. I seem to remember long ago reading some of Mr Kings work and thought that port positioning was critical to the MLTL design. I'm afraid the maths is a bit beyond me but I have previously built sealed and ported designs with the JX92S units. I would now like to try an MLTL design.

Thank you

Tony
 
Jim,

Thank you very much for your reply. Since I wrote the question I have been doing plenty of "forum hopping" I have now noticed the new second generation MLTL designs on Jordan-usa.com. I think that the 35" design will be my choice. I want to build the cabinets from 18mm birch ply and I am thinking of building small plinths to bring the driver to ear height and also to house the bsc components.

Tony
 
Tony,

The 35" MLTL design looks to be the sweet point for the new designs. I haven't heard these new MLTLs so I can only compare versus simulated responses. The sims look favorable.

On the speaker height issue: you could add a 'false' bottom to the enclosure to raise drivers and use the lower enclosed space for the crossover.

Jim
 
I'm tempted to try the Ribbon / Jordan design, the only problem is that I have to mount the tweeter below the woofer [don't ask] so do I need any adjustment to the crossover design in order to compensate for this position?

I should say that my listening position places tweeter at the middle or ever so slightly above ear level.
 
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