Aurousal MLTL using paired JX92s

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There was a thread about Aurousal A1s a year back. These were stand-mounted and used a JX92 in a 10 litre box.

At the HiFi show at Heathrow, London yesterday I heard the Aurousal VS Floorstander. This used 2 JX92s per channel wired in a “line array” ie the pair were close together at ear height. Impedance was quoted as 4 Ohm so presumably they are in parallel. I was told that the tweeter (domed neodymium) was switchable according to taste and “room ambience” that the JX92s are run full range, no xover and that the design uses a BSC. (VS = virtual source and seems to be a description of line array.)

The cabinet is 20mm thick inc veneer and is a ”quarter-wav MLTL based on Martin King’s spreadsheets on DIYAudio”. External dimensions are given as 107.5mm h x 21.5mm w x 26.8mm d giving a volume of about 35 litres, a line length of 41” and a CSA of about 62 in sq. ( It seems easier to mix imperial and metric units at this point). I was also told the line is heavily damped. Port is very low on the front. Bass is quoted as 30Hz (-3db) 25Hz (-6db) and they were in corners.

I had thought about using twin JX92s myself in the 48” MLTL, and I have to say that I was pretty impressed by these. They had very good bass, a rich full bodied mid, all the speed and detail of the JX92 and only the slightest hint of cone breakup if you were listening for it. Two other JX92 owners were also impressed. I’m certainly going to have another look at a two driver design.
Definitely not the MLTLs from the Jordan site but I bet it inspired them. I'll mention this to Ted and see if we can beef up the wording on the Jordan site to indicate that any designs based on or derived from the MathCad spreadsheets should be licensed from MJK.

The speaker doesn't appear on their website yet so maybe they were testing a design before licensing the software, but even so ...
Hmm. Looking at the available data on the speakers, references to Martin are mysteriously absent, so they might either have been economical with the old actualite at Heathrow, or this could be another successful rip-off of Martin's worksheets.

That said, if the Aurousal people do indeed frequent the forum, perhaps they'd like to join the thread and clarify these questions. It would certainly be in their interest to do so.
Hi, Let me introduce myself - I am Kevin Warne from Aurousal and I do have a private licence with Martin King. My private email address is

The project started off as a DIY one and the speaker is still not quite ready for commercial launch so have not got around to upgrading the license yet. The show alone cost us £900 and we are certainly not big-league. I have previously kept my DIY and commercial interests separate but the line is blurring recently. Have been a DIY'er for 25 years and still see myself as one.

Judging by the interest at the show it does look commercially promising. Happy to answer any questions here. What's the policy for manufacturers on this site? It's certainly a great discussion forum.

Welcome to the forum and thank you for posting a reply. I think you can understand as a DIY'er that many of us want to be sure that Martin is treated fairly. Although I have never used his MathCAD sheets or tables, I hate to see anyone suffer as a result of helping this community. Martin has been quite generous in his contributions to the hobby, as evidenced by the numerous projects inspired by his work.


FYI: I emailed a link to this thread to Aurousal this AM (US: Eastern Std Time) to see if anybody there had a comment to add. I'm happy to see Kevin is contributing, and certainly hope that any issues concerning MJK's licensing can be resolved to everybody's satisfaction.
Before anybody gets too excited, lets all wait and see how the Aurousal speaker does in the market. I hope things go well for them. It would seem that Aurousal and another small company I found recently both have DIY license agreements in place and are trying to transition into the commercial speaker business. They are doing what I only dream of doing. It is nice to know that the software is capable of producing something that people feel is worth selling. The next step is to see if the software produces something that people feel is worth buying.
Well, I hadn’t expected the thread to take the direction it has so far – I just wanted find out how the MLTL had been made with a view to doing my own take on it.

I hope it is now sorted and someone can tell me how the line length which is 7” less than the 48” I built, produces such good bass, and what (if any) drawbacks there are
to this design.
Hi Nardis - A year or so ago Scott did some sims for me of the Jordan MLTL at 31, 45 and 48 inches, which gives a sense of how the length alters the FR (at least for those of us who think in pictures). If Scott no longer has copies, I'm happy to post the images here.

I haven't tried pairing up JX92s but have tried this with the JXR6 (using two per channel) and it gave a marked improvement below 200Hz, warming out the sound and giving it more weight.
Drawbacks... well, perhaps not in the FR. But you might want to keep a close eye on the driver excursion, depending on how low you're tuning, and also what sort of alignment you are aiming for. Of course, using two drivers doubles your power-handling & nominally halves excursion at a stroke, though if both are on the front panel the downside is that lobing issues from the driver outputs are going to become increasingly an issue as frequency rises (I gather Jordans are somewhat better than most in this respect). Bipole solves that, but the price of that is that it needs space behind the cabinet, and it's better in the fresnel zone as you're not maximising the possible acoustic power at the listening position.
We’ve gotten adjusted to having 48”+ MLTLs, even lining up the bottom of the odd picture with the top of the cabinet.
In a previous thread GM confirmed that with 2 drivers you would need to double the CSA of the 48” and lengthen its port.
Is the position of the single driver determined by its location within the line or by the need to have it at ear height?
What would be the optimum position for 2 drivers?
I’ve got a ribbon – an oblong Fountek JP3 - whose height is almost the same as a JX92S. Kevin’s design doesn’t use D’Appolito MTM configuration but treats the drivers a small line display with a little tweeter above them.. So what would be the optimum heights and arrangement for 2 JX92s at 140 mm diameter each plus a ribbon 115mm high?
Driver location is tailored to provide the flattest response. Optimum position for two drivers, assuming you're simply doubling the cabinet CSA & adjusting the vent slightly, will be as per the single driver version.

I'm not really a fan of systems using two or more FR drivers on the same flat baffle -it's looking for trouble IMO. Still, YMMV as ever. I'd probably just mount them as close together (vertically) as possible, & stick the tweeter to the side, again, as close to the main units as possible.
Nardis said:

Is the position of the single driver determined by its location within the line or by the need to have it at ear height?

What would be the optimum position for 2 drivers?

So what would be the optimum heights and arrangement for 2 JX92s at 140 mm diameter each plus a ribbon 115mm high?

Both, I use a design routine that calcs what I believe is the optimum point for the least damping material required along the line for a bottom located vent, so when Bruce P asked for a long version of my 31" MLTL I just used it to find an ear height variant while maintaining a constant CSA.

Since this is the case, using this as the mean to vertically position two drivers seems reasonable as this will be the summed acoustic center and IIRC MJK proved it mathmatically awhile back.

The ribbon doesn't count since it's not being loaded by the cab, though if its placement needs to be at ear level, then this in theory affects the cab's design if it's a 2.5 way, otherwise it should be beside them and make them a mirror image pair since in theory the tweeter should be oriented to the outside.

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