cheesehead said:
The main reason would be to make the speaker taller and skinnier if that's what you want. I guess you might be able to eek out another dB at 40Hz, but the main reason would be desired box shape.
I don't recommend reducing the CSA much, if any. If you want more pipe loading, ergo a lower Fb, then maintain the same CSA and try longer lengths. The optimum driver position will shift upwards some and the vent length will shorten.
FWIW, this came up in another thread and I calc'd a max practical length of 48" using the same CSA, density, vent diameter, but with driver down ~15.46"/2.75" vent length. AFAIK, no one's built it so as always YMMV, though I see no reason why it won't perform as predicted.
GM
Well these look good as a first project, and I've even got a kind of thumbs up from the wife.
Just one question, when it says 0.54ib stuffing, what does this mean?
Cheers
Lee
Just one question, when it says 0.54ib stuffing, what does this mean?
Cheers
Lee
Re: Another way to use Jordans
That's about where I eventually want to go...
If the Jx92's work out well, I'd like to eventually move them to surround/center duties and build 2-ways (using either the Jx92 or Jx53) as mains, as per this prior thread.
mk
nonamekid said:
That's about where I eventually want to go...
If the Jx92's work out well, I'd like to eventually move them to surround/center duties and build 2-ways (using either the Jx92 or Jx53) as mains, as per this prior thread.
mk
Yes, good thread - thanks. I have thought of using the JX53s in a similar config to my current one, but crossed higher, say about 200 or a even bit higher. I don't know what they sound like though - it they're anything like the 92s they would be good. I'd still use the the Peerless subs, I think - Jordan's bass drivers are pricey and can't quite do what the Peerless can (and they're cheap!) The Peerless subs are good and flat up to 1000hz and with the closed cabs of the right size go way down real flat. Specs: Fs: 25 Hz * SPL: 87 dB 2.83V/1m * Vas: 3.07 cu. ft. * Qms: 2.65 * Qes: .54 * Qts: .45 * Xmax: 5.5mm * I'm sure the 53s would be good too, but the 92s sound so good I probably won't get around to it anytime soon. I may experiment with different x-over frequencies to see how my room responds. Probably many other good full range drivers would be great in this kind of setup too.
The pair of subs and active x-over was really the key to freeing the sound for me. I tried a single sub centrally located, but it's box was big and placement in my studio was difficult. (I could hear its location too, despite common wisdom saying that I wouldn't!) It's amazing how much ambience lives in the 20 - 100hz zone (and lower), especially the sound of large concert halls. Big rooms have low modes which I think contribute greatly to the sense of the space (especially in classical recordings) and can only be reproduced with good subs. It's a subtle effect. It's amazing how little information seems to come out of my subs if I run them alone. Yet their addition to the 92s is magical.
The pair of subs and active x-over was really the key to freeing the sound for me. I tried a single sub centrally located, but it's box was big and placement in my studio was difficult. (I could hear its location too, despite common wisdom saying that I wouldn't!) It's amazing how much ambience lives in the 20 - 100hz zone (and lower), especially the sound of large concert halls. Big rooms have low modes which I think contribute greatly to the sense of the space (especially in classical recordings) and can only be reproduced with good subs. It's a subtle effect. It's amazing how little information seems to come out of my subs if I run them alone. Yet their addition to the 92s is magical.
The 53s go higher and sound slightly more open but a single driver probably needs to cross over higher than 200Hz (depending on slope). Ted recommends 500Hz, first order.
BTW, the Jordan bass units are no longer available, due to manufacturing difficulties for the relatively small quantities involved (and the fact that no one else seems to have woken up to how advanced they are). I believe Ted is researching commercial alternatives.
Back to the JX92 ML TL - assuming the cross sectional area is kept the same, is there any reason not to use a traingular cross-section cabinet, rather than rectangle?
Colin
BTW, the Jordan bass units are no longer available, due to manufacturing difficulties for the relatively small quantities involved (and the fact that no one else seems to have woken up to how advanced they are). I believe Ted is researching commercial alternatives.
Back to the JX92 ML TL - assuming the cross sectional area is kept the same, is there any reason not to use a traingular cross-section cabinet, rather than rectangle?
Colin
Colin said:
hope it's just those... www.creativesound.ca was down to their last 8 Jx92s when I ordered...
mk
Colin said:
Bummer! I just recently learned that he had them and had started doing a few sims...... Combined with the JX92S, a two way TL or ML-TL sims a pretty spectacular design and I'm surprised none of the ~FR entrepreneurs appears to offer either a kit or finished version.
Shape is irrelevant as long as the CSA remains ~constant and any bend radii are sufficient to pass the intended BW. A triangle will be more efficient since it has one less turbulent corner and no parallel walls, though in such a small cab I doubt the differences would be audible enough to be obvious due to being pressurized over ~ all of its intended BW. In larger cabs driven with either large or multiple drivers, it's well worth the extra woodworking IMO. Stuck in corners, they are the best performing speaker systems I've designed/built.
GM
Colin said:
Damn... awefully nice drivers those... well i guess that will increase the value of the JX150s i have still in the boxes.
dave
I seem to remember Steve Margolis (7V) said something this time last year about Jordan giving up manufacturing completely.
However, this is probably not what you all want to hear...
However, this is probably not what you all want to hear...
I saw Ted a couple of weeks ago and can confirm that it's only the bass units which have ceased manufacture. Some of the components were supplied by a company which requires much higher OEM orders than those particular drivers justify. If he can find an alternative manufacturer, they may go back into production.
The JX92 and JX53 are definitely continuing!
His website will be updated soon with details.
Colin
The JX92 and JX53 are definitely continuing!
His website will be updated soon with details.
Colin
GM said:
Thanks for that. Your JX92 MLTL seems a prime candidate for that shape, giving room to have a front-facing port if necessary.
BTW, what are the performance trade offs of your sim of the 48" tall version.
Colin
PS Ted mentioned that the JX92 would be a good partner for the JX53 for smaller systems. The sensitivities need adjusting, however.
Drat. This seems to be another thread I've killed off by asking too many questions.
Colin the Thread Slayer.
Colin the Thread Slayer.
Colin said:
Nah, the "thread" is alive and well; I'm cutting & gluing wood & waiting on my drivers to build these things. Using the rotozip and router help to decrease my HF hearing so that these full-rangers will sound better!
The only thing I changed was to make the cab front a little longer so that I can bolt in the bottom piece with the port and keep it hidden. I figure if the port is easily removable I might even be tempted to try tuning it after assembly.
Pity you waited until after I started cutting to bring up the triangular x-section idea, tho!
mk
Triangle Idea
Yeah, I thought a triangular cross-section was a neat idea too. I played around with it a little and came up with a trapezoidial form that would allow you to have a front firing port... I think. Of course I would want and design change to be blessed by GM 😉 before I got serious about it.
A trapezoid has four sides with two being parallel. My proposed design has the following inside dimensions:
First parallel side = 2" (this is the back)
Second parallel side = 6.875" (this is the front)
Distance between the two parallel sides = 6.770"
Draw the first side, then draw the second side centered on the first one 6.770" below the first one then draw lines to connect the end points and you have the cross-section.
GM's original MLTL CSA = 30.0407 with a total volume = 932.46332
This trapezoidial version has a CSA = 30.04187 and a total volume = 932.4996
This form would allow you to exit the port out the front, although I'm not sure exactly where the port would be placed.
Comments?
Yeah, I thought a triangular cross-section was a neat idea too. I played around with it a little and came up with a trapezoidial form that would allow you to have a front firing port... I think. Of course I would want and design change to be blessed by GM 😉 before I got serious about it.
A trapezoid has four sides with two being parallel. My proposed design has the following inside dimensions:
First parallel side = 2" (this is the back)
Second parallel side = 6.875" (this is the front)
Distance between the two parallel sides = 6.770"
Draw the first side, then draw the second side centered on the first one 6.770" below the first one then draw lines to connect the end points and you have the cross-section.
GM's original MLTL CSA = 30.0407 with a total volume = 932.46332
This trapezoidial version has a CSA = 30.04187 and a total volume = 932.4996
This form would allow you to exit the port out the front, although I'm not sure exactly where the port would be placed.
Comments?
A little more info
The above trapezoidial cross-section uses all of GM's other inside dimensions for the original MLTL:
L = 31.04"
XO = 11.14"
Vent = 2" diag x 5" Length
Stuffing = 0.54lb
The above trapezoidial cross-section uses all of GM's other inside dimensions for the original MLTL:
L = 31.04"
XO = 11.14"
Vent = 2" diag x 5" Length
Stuffing = 0.54lb
Stuffing Question
Hello ,
Between two days or so the speakers will thake its form here , the JX92 are already playing in other enclosure.
How has to be fitten the stuffing material?
At the bottom ?
Right in the back of the driver?
Both?
🙂
Hello ,
Between two days or so the speakers will thake its form here , the JX92 are already playing in other enclosure.
How has to be fitten the stuffing material?
At the bottom ?
Right in the back of the driver?
Both?
🙂
Anyone cutting out wood, look away now. The other neat thing about the triangle idea is that the width of the internal surfaces works out at 7.75 inches, which avoids those tricky fractions.
The triangle would also place the JX92 at their recommended toe-in angles, when the enclosure is against a back wall.
Howeverr I'd like to hear more about the trade offs on the 48" high MLTL before starting my boxes ...
Colin
The triangle would also place the JX92 at their recommended toe-in angles, when the enclosure is against a back wall.
Howeverr I'd like to hear more about the trade offs on the 48" high MLTL before starting my boxes ...
Colin
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