JX53 linear array

If you go to

www.ejjordan.co.uk/jordan/systems/jx53_system.html

The top drawing will give you the cutout size per driver. It's then a case of cutting the four holes and stacking the drivers vertically in a sealed box of around 4.5 to 6 litres internal volume. If you search for JX53 in this forum, there have been a couple of pics over the last few months. The 7th Veil uses an identical physical layout of the drivers so that should give you a good idea.

However I agree that the drawings on the site aren't very clear. They are a hangover from the old site so I'll pester for them to be updated sometime.

If it is of interest, I'm putting together a linear array at the moment and can take a pic later today to show you the arrangement. It's a TL cabinet rather than a sealed box (although it could be used sealed and would be about the right internal volume).

I'll post the pic later this weekend.

Colin
 
I haven't used Jordan drive units for many years. I don't use any filter with the Bandor 50mm drivers but the Jordans are designed to be crossed over at 500Hz.

It is important to mount the drivers as close together as possible to prevent cancellation effects at high frequencies. You don't need a separate enclosure for each unit - one large enclosure will be better.

I have found that internal design of the enclosure is particularly important with these drivers. A more conventional woofer-tweeter arrangement generally employs a closed back tweeter above 1kHz-3kHz so enclosure shape isn't important above these frequencies. The Bandor/Jordan approach is different.

Interestingly, Ted toes his arrays in to cross at a point well in front of the listeners. This gives very good imagery over a wider width than conventional but I tend to use my speakers with less toe-in as i find this gives a better high frequency performance.

Good luck with this project. I'm happy to help if I can.
 

soongsc

Member
2005-03-26 2:31 pm
Taiwan
Unless you already have the driversm you'd better make sure which ones you get. The face plate dimensions between the new and old are different. The old ones have a 75mm x 95mm face plate, the new ones have 77mm x 90mm. The mounting holes are also in different locations.

I believe the Jordans cross at 150 Hz for the line arrays, this is because you have more total cone area. For just one driver, I recall crossover at around 450~500 Hz is recommended.

The toe in requires the high frequencies to be slightly enhances to get the right effect.
 
Thanks guys.

I'm glad the confusion with the plans isn't just me. I don't already have the drivers as I want to make sure, with that kind of expenditure, that I have a workable cabinet design.
I like the Jordan drives because they have been designed with flush mounting in mind. I have an active powered sub, so I'll be crossing over fairly high, regardless of what project I eventually build.
The speakers will also be an integral part of a HT rig, so sheilded drivers are a must.

I may save myself a bundle and go fostex, there's a folded spiral horn design made for mounting on the wall that I came across on the old single driver website that also looks good.

However, for now, the Jordans still rank foremost in my interest level. I'll keep looking for pictures of a completed array.

Thanks.
 

soongsc

Member
2005-03-26 2:31 pm
Taiwan
Re: Thanks guys.

Cryo_jumper said:
I'm glad the confusion with the plans isn't just me. I don't already have the drivers as I want to make sure, with that kind of expenditure, that I have a workable cabinet design.
I like the Jordan drives because they have been designed with flush mounting in mind. I have an active powered sub, so I'll be crossing over fairly high, regardless of what project I eventually build.
The speakers will also be an integral part of a HT rig, so sheilded drivers are a must.

I may save myself a bundle and go fostex, there's a folded spiral horn design made for mounting on the wall that I came across on the old single driver website that also looks good.

However, for now, the Jordans still rank foremost in my interest level. I'll keep looking for pictures of a completed array.

Thanks.

1. The current JX53 drivers are not shielded, but I don't think you will have problems with LCD or plasma displays. If you wall mount these, they will be far enough away from CRTs that they won't have effect.

2. The line arrays are real simple, just build one box with the drivers lined up against each other. They are already designed such that the cones are as close as possible when lined up. The box shape could be any shape, and you only need one box.
 
The Mark Audio site (www.markaudio.com) also shows the new JX53s being used in pairs rather than 4. Might be worth trying. When I get my array finished, I will experiment with connecting 2 vs 4 drivers and report back.

BTW, the JX92 is supposed to mimick the performance of the array at lower cost. It is already shielded and does throw out a very wide and deep stereo image if crossed in front of the listener.

Colin
 
The mark audio site was a big help thanks.
The more I think about the total cost of the project, the more I think I had a momentary lapse of reason, although the construction looks quite simple.

I was originally considering the JX92s but have been warned by close friends who also share this DIY bug, that they won't handle the dynamics required for HT at 'normal' levels. That, plus I was told that the JX53 array sounds better than the JX92 was why my interest moved drivers.

Last summer I was corresponding with Cornu and he sent me plans for the flat spiral horns. I never did build them, but thinking about them, I could build a complete set of 5 (or 7) for HT, for < the cost of 2 JX53 arrays.
I notice he has gone commercial with the design (switching from fostex to lowther) and the reviews are great.

The longer I wait to build something, the worse this itch gets, but spousal acceptance prevents me from excessive experimentation (damn).

I wonder if there are any good 'cheap' drivers that lend themselves to array designs?
 

soongsc

Member
2005-03-26 2:31 pm
Taiwan
Once you start doing your own speakers, you're probably always going to figure out how to get them better. There are just so many things to learn. The JX53 array had many advantages. Just listening to one JX53 alone has me convinced that these are good for vocals and chamber music, and well enough dynamics for listeneing in the evenings. I think the JX92S would also be well if you are not listening to large scale performances with more than ten people/instruments. With two JX92S as shown at the markaudio site, there is no reason that you will feel loss of dynamics.

I am currently working on some circuits to better reveal the potential of the JX53 and JX92. After the process of getting feedbacks and comments, I might be allowed to publicly publish the circuit or allow people whom already have these speakers to try out if they wish to participate.

What's HT? Horizontal Tail? :confused:
 

soongsc

Member
2005-03-26 2:31 pm
Taiwan
One serious system is good. I actually plan to use the JX92S as surrounds. The main speakers are when you do serious listening, so you probably don't want sacrific too much to get the other parts. If you start out with good mains, and economic surrounds, then gradually upgrade the surrounds, in the end you will get a very good system. If you select the design such that the mains can also become surrounds in the process, this is probably strategically best since you are always using the best stuff for the mains.
 
I have thought about this design for many years now.I first heard the bandor driver about 10 years ago.I had brain daley in ca design me a pair of speakers using an accuton tweeter--2--- 2' bandor drivers for mid's and a eton 8.5 for the bass.

I had that speaker for many years ,but when i moved everything to a smaller room the speaker did not sound good so i sold them.The integration between eton bass and bandor---did not sound right sitting closer to the speaker--the bandor's are so fast and clean.

But the midrange using the bandor drivers was by for the fastest and cleanest i have heard yet.An i have missed that sound for years now.

The cost of a line array of bandor or jordan is so high i have not yet gone that route.

I keep reading that you can loose treble response on a line array like that,but i see line arrays produced all the time.

I have never heard the jordan 2' driver ,but i would assume it is very much like the bandor.


regards
 
The Bandor 50mms have resonant frequencies in the region of 65hz (depending on the impedance and precise specification); the Jordan JS53 has a resonant frequency of over 100Hz. The Jordans claim a frequency response to 30kHz, the Bandors claim 20kHz. Bandor drivers use a conventional spider suspension whereas the Jordans don't.

Each have different strengths and weaknesses. 'Almost equal' they ain't.