I've been in touch with Ted Jordan and alerted him to Zaph's findings, in case anything is going adrift with current units.
The first thing he noticed was that the web published spec was out on resistance and should read 6 ohms, not 4.5. Department of mea culpa as that typo was probably mine when I worked on the site. The published spec will be updated.
Ted is going to pull out a recent sample JX92S and check the spec. I'll post here when I hear from him. (Ted prefers not to join in the forums.)
The first thing he noticed was that the web published spec was out on resistance and should read 6 ohms, not 4.5. Department of mea culpa as that typo was probably mine when I worked on the site. The published spec will be updated.
Ted is going to pull out a recent sample JX92S and check the spec. I'll post here when I hear from him. (Ted prefers not to join in the forums.)
I hope the discrepancies will have no siginificant impact on, for example, GM's MLTLs dimensions. I am about to finish gluing the 31' version and would be very sad to know at this stage that the measures should be different.
Colin said:
The first thing he noticed was that the web published spec was out on resistance and should read 6 ohms, not 4.5.
If the other specs are 'correct', then the slightly increased BL in theory is an improvement, though I seriously doubt it would be audible in-room with any TL, MLTL alignments and my SWAG not even the tiniest sealed ones.
Anyway, looking forward to his thoughts/findings on the subject.
GM
A Sanchez said:
I hope the discrepancies will have no siginificant impact on, for example, GM's MLTLs dimensions.
Worst case scenario based on my comments here is you may want to either increase the vent length some or add a bit of stuffing inside the existing one to suit, though I imagine had these specs discrepancies not been noted you would be pleased with the design as is since the room dominates the BW they affect: http://www.diyaudio.com/forums/showthread.php?postid=1465991#post1465991
GM
Colin said:I've been in touch with Ted Jordan and alerted him to Zaph's findings, in case anything is going adrift with current units.
The first thing he noticed was that the web published spec was out on resistance and should read 6 ohms, not 4.5. Department of mea culpa as that typo was probably mine when I worked on the site. The published spec will be updated.
Ted is going to pull out a recent sample JX92S and check the spec. I'll post here when I hear from him. (Ted prefers not to join in the forums.)
Is there any update on this? I had emailed them on March 25 and sadly there has been no response.
Perhaps I am thinking about this too much.
If you take the specified Qes = 0.58 and Qms = 1.35, I calculate Qts = 0.406 which matches the specified Qts = 0.4.
However, using the specified Fs = 45 Hz and Vas = 15.28, I calculate SPL = 85.84. Jordan has specified 88.
Is this another typo, or is it possible that have they used a specified SPL to calculate Vas?!
Am I making too much out of this? Is a 30% variation Qts no big deal?
Also, note that their impedance plots are only from 30 Hz to 10kHz. Is this why they have Re = 6 and others are measuring closer to 5 ohms?
No update received yet. Jordan commercial business is handled by EAD or the distributors. Ted is mostly consultancy now. As soon as I hear anything from Ted I'll post here.
This month's HiFi News review of the Aurousal A1 mk 2 seems to fit with the Jordan sensitivity, as far as I can tell. The mk 2 features the recommended BSC for the 8 litre enclosure so loses 3-4dB from the raw Jordan spec.
This month's HiFi News review of the Aurousal A1 mk 2 seems to fit with the Jordan sensitivity, as far as I can tell. The mk 2 features the recommended BSC for the 8 litre enclosure so loses 3-4dB from the raw Jordan spec.
As per the title of this thread, I'm embarking on an enclosure that has not been tried before with the JX92S drivers, AFAIK (mine are not from the GB) - see the thread here: http://www.diyaudio.com/forums/showthread.php?s=&threadid=119903
The final version I am having built, by the kindness of WoddturnerFran (as the name suggests he's a dab hand at wood & just finished some Fonkens), is this one: http://spiralspeaker.web.fc2.com/aaaspeaker/extra/engag180z/eng-ag180z.html
These cabinets are originally for the Fostex FE126E drivers & I'm wondering what, if any, changes to dimensions should be made?
Any comments/changes appreciated before wood is cut,etc?
The final version I am having built, by the kindness of WoddturnerFran (as the name suggests he's a dab hand at wood & just finished some Fonkens), is this one: http://spiralspeaker.web.fc2.com/aaaspeaker/extra/engag180z/eng-ag180z.html
These cabinets are originally for the Fostex FE126E drivers & I'm wondering what, if any, changes to dimensions should be made?
Any comments/changes appreciated before wood is cut,etc?
Built these & initial reports are good: http://www.diyaudio.com/forums/showthread.php?postid=1481149#post1481149
gmilitano said:However, using the specified Fs = 45 Hz and Vas = 15.28, I calculate SPL = 85.84. Jordan has specified 88.
Is this another typo, or is it possible that have they used a specified SPL to calculate Vas?!
How are you calculating Vas given Fs and sensitivity?
You can calculate efficiency with Fs, Vas and Qes. You have to assume a density for air.
http://en.wikipedia.org/wiki/Thiele/Small
http://en.wikipedia.org/wiki/Thiele/Small
Sadly, there has been no response from the manufacturer or EAD. Try both the T/S numbers (published and measured) for your enclosure and see how much the difference is. It may not be all that significant.
Let us know how you make out.
Cheers
Let us know how you make out.
Cheers
I spoke to Ted a couple of weeks back and he confirmed that his sample matched the spec on his website. He was able to vary the spec depending how he measured it. I've suggested a short explanation might be helpful when he has time to put one together.
- Status
- Not open for further replies.
- Home
- Loudspeakers
- Full Range
- Any enclosure ideas for the "new" JX92S?