Without pre-empting Jim, my guess is that 3k allows the tweeter to take over before the JX92 becomes too directional.
BTW, reference Jim's post a little earlier: I've been running a smaller JX92 system and sub combination. The sub is a Rega Vulcan, capable of reaching below 30Hz in my room (it has a claimed low of 17Hz). It crosses to the smaller system at 60Hz. Compared to the MLTL, there is very little in it. The MLTL can reach 35Hz and I prefer the MLTL bass overall as the stereo extension into LF gives it more depth. (This may be an illusion, I guess, caused by setting off two sets of room resonances rather than one.) However the sub makes a very tidy system.
BTW, reference Jim's post a little earlier: I've been running a smaller JX92 system and sub combination. The sub is a Rega Vulcan, capable of reaching below 30Hz in my room (it has a claimed low of 17Hz). It crosses to the smaller system at 60Hz. Compared to the MLTL, there is very little in it. The MLTL can reach 35Hz and I prefer the MLTL bass overall as the stereo extension into LF gives it more depth. (This may be an illusion, I guess, caused by setting off two sets of room resonances rather than one.) However the sub makes a very tidy system.
Colin said: "Without pre-empting Jim, my guess is that 3k allows the tweeter to take over before the JX92 becomes too directional."
That is exactly the reason for the crossover at 3 kHz. The JX92S begins to be directional at that point so the crossover was set to assure that the in-room response was well balanced between it and the ribbon tweeter. The goal was to maintain wide dispersion across the frequency band with a good power response. Beyond 3000 Hz the vocal range is limited so you don't cause noticeable impact on vocals.
Also I agree with Colin on the subwoofer. For most music you should not need a sub with the MLTL version. Unless you favor bass heavy music, the sub will not add much.
That is exactly the reason for the crossover at 3 kHz. The JX92S begins to be directional at that point so the crossover was set to assure that the in-room response was well balanced between it and the ribbon tweeter. The goal was to maintain wide dispersion across the frequency band with a good power response. Beyond 3000 Hz the vocal range is limited so you don't cause noticeable impact on vocals.
Also I agree with Colin on the subwoofer. For most music you should not need a sub with the MLTL version. Unless you favor bass heavy music, the sub will not add much.
Jim Griffin said:
forgot about that. but in that case why not use a good 5" midbass or is the JX92 really a good midbass with a HF response that allows it to be used as a fullrange?
Forgive me for playing devil's advocate here but I am just trying to debate the use of the JX92 as a midbass. I hope there are no hard feelings. I have great respect fro both Jim and Colin (as well as Ted Jordan).
Navin,
I doubt that you will find another 4" driver that can match what the Jordan JX92S will do for its size. The JX92S has a low Fs (45 Hz), good extension (Xmax is 4.5 mm), reasonable sensitivity, and for a metal cone driver it has few audible breakups. Plus it produces sound that doesn't fatigue. While you can likely match the performance of the JX92S with a 5" or 6" driver, the enclosure size increases and the sound quality may suffer in the process. Finally, a quality European made driver, for example, from the Seas Excel or Scan Speak lines will cost just as much as the JX92S. Bottom line is that the JX92S is a excellent mid-bass driver for a two-way system such as mini-monitor or MLTL.
Jim
PS - I have my Jordan JX92S/Aurum Cantus G2si MLTL configured so that I can switch between the two-way version or the full range JX92S. Hence, you can hear the spatial content that the ribbon tweeter adds vs. just the JX92S alone.
I doubt that you will find another 4" driver that can match what the Jordan JX92S will do for its size. The JX92S has a low Fs (45 Hz), good extension (Xmax is 4.5 mm), reasonable sensitivity, and for a metal cone driver it has few audible breakups. Plus it produces sound that doesn't fatigue. While you can likely match the performance of the JX92S with a 5" or 6" driver, the enclosure size increases and the sound quality may suffer in the process. Finally, a quality European made driver, for example, from the Seas Excel or Scan Speak lines will cost just as much as the JX92S. Bottom line is that the JX92S is a excellent mid-bass driver for a two-way system such as mini-monitor or MLTL.
Jim
PS - I have my Jordan JX92S/Aurum Cantus G2si MLTL configured so that I can switch between the two-way version or the full range JX92S. Hence, you can hear the spatial content that the ribbon tweeter adds vs. just the JX92S alone.
Jim Griffin said:
Comparing the JX92 to a 5" driver (like Scan Speak's 15W8530 as used in th3 ZD5) may not be right. Most 5" drivers I know need far bigger boxes than the JX92 can work in. In fact I have realised that the JX92 is very flexible in the variety of boxes it can work in from a 3 liter sealed box (with limited F3) to a 25 liter TL. The 8530 for example needs atleast 10 liters.
If one had to compare the JX92 to another driver one would have to consider drivers like the Excel W12CY and maybe the FR125/WR 125. Of these the W12CY costs about as much as the JX92 BUT does not have the extended HF response of the JX92 but when the JX92 is mated to the tweeter we do not use the HF response anyway.
I am sure the G2Si adds a lot of air to the JX92. I also understand that the reason the crossover point chosen is so low is becuase of the beaming of the JX92 at above 3K. I have heard the JX92 in a 8 liter box and while it's LF and midrange is excellent I did not like it's HF so I appreciate the need for a tweeter. The electronics used were a Roksan CD player and amp.
I was just wondering (since we are now talking about 2 ways instead of fullranges) if there would be another woofer-tweeter combo (W12CY mated to the G2Si, OW4, Seas T25 Excel, or Scan Speaks 9500 / 9700) would offer a credible alternative with similar low freq extension, midrange smoothness and HF air in a small box. The W12CY used in the example above is about 3-4db less sensitive than the JX92.
For HT however I think the JX92 is a fantastic driver as it allows you to use it as a fullrange AND as a 2 way. I know of only the FR125 that allows this (albeit I have not heard the FR125/WR125).
Hi Ray
I like the 92 as is, so haven't pursued the ribbon route. I did try it with a rough and ready crossover to the JXR6, which did clean up the highs. The JXR6 has a particularly fine HF but even used on its own, down to 120Hz or so, I prefer the imaging on the JX92 and I'm convinced this is due to its directional characteristics.
I'd like to hear the ribbon variant sometime, though, to see what my more hairshirt approach is missing.
I like the 92 as is, so haven't pursued the ribbon route. I did try it with a rough and ready crossover to the JXR6, which did clean up the highs. The JXR6 has a particularly fine HF but even used on its own, down to 120Hz or so, I prefer the imaging on the JX92 and I'm convinced this is due to its directional characteristics.
I'd like to hear the ribbon variant sometime, though, to see what my more hairshirt approach is missing.
Hi, Jim,
Thank you for your suggestion.
I believe the the MLTL is great plan for this driver. However, I like my current speaker very much! I didn't mean this speaker leak bass, actually I think it is very nice on everything compare to its compact size. I had owned ProAC Response 2.5, the mini-monitor still has lots of good feature can beat that expensive speaker! It doesn't need any upgrade for most music, including Jazz, My concern is synphony only. I don't want to abandon my current cabinet and rebuild a new one. I will consider to build or buy a sub-woofer to enhance the bass.
BTW, could you please send my your original mini-monitor KIT plan and tech information? If I build a sub, what approximate frequency cut-off I should set on the sub?
Thanks again!
Albert
Thank you for your suggestion.
I believe the the MLTL is great plan for this driver. However, I like my current speaker very much! I didn't mean this speaker leak bass, actually I think it is very nice on everything compare to its compact size. I had owned ProAC Response 2.5, the mini-monitor still has lots of good feature can beat that expensive speaker! It doesn't need any upgrade for most music, including Jazz, My concern is synphony only. I don't want to abandon my current cabinet and rebuild a new one. I will consider to build or buy a sub-woofer to enhance the bass.
BTW, could you please send my your original mini-monitor KIT plan and tech information? If I build a sub, what approximate frequency cut-off I should set on the sub?
Thanks again!
Albert
Jim Griffin said:
Albertshi,
I don't have a link to the original mini-monitor design but the mini-monitor with a ribbon link below will summarize the enclosure construction. The original mini-monitor used a 1.5 mH coil and 4 ohms resistor in parallel and that circuit was then placed in series with the positive terminal of the speaker for baffle step correction. The mini-monitor with a ribbon write-up is at:
http://www.esnips.com/doc/0cd36443-0972-477d-9e54-1267c790b359/JX92SG2siDesignPak
For subwoofer integration I suggest that you stuff the port on the mini-monitor (effectively makes the box a sealed enclosure) and crossover in the 80-90 Hz range.
Jim
I don't have a link to the original mini-monitor design but the mini-monitor with a ribbon link below will summarize the enclosure construction. The original mini-monitor used a 1.5 mH coil and 4 ohms resistor in parallel and that circuit was then placed in series with the positive terminal of the speaker for baffle step correction. The mini-monitor with a ribbon write-up is at:
http://www.esnips.com/doc/0cd36443-0972-477d-9e54-1267c790b359/JX92SG2siDesignPak
For subwoofer integration I suggest that you stuff the port on the mini-monitor (effectively makes the box a sealed enclosure) and crossover in the 80-90 Hz range.
Jim
Albertshi,
What I'm telling you is that the design with the ribbon has the same size box as the original mini-monitor like yours. If you were building one without the ribbon, just use the same sizing but don't cut the hole for the ribbon tweeter and leave out the crossover (essentially replace it with the baffle step circuit).
The near field plots in the write-up are box dependent so the low end bass performance would be the same for either design. Pay attention to the discussion about the roll-off points for ported and sealed would be the same for either design inclduing yours.
I do have the original plans that I used for my mini-monitor construction back in 2001 if you wish to e-mail me. My goal was to direct you to the design with the ribbon as it essentially encompasses the older version.
Jim
What I'm telling you is that the design with the ribbon has the same size box as the original mini-monitor like yours. If you were building one without the ribbon, just use the same sizing but don't cut the hole for the ribbon tweeter and leave out the crossover (essentially replace it with the baffle step circuit).
The near field plots in the write-up are box dependent so the low end bass performance would be the same for either design. Pay attention to the discussion about the roll-off points for ported and sealed would be the same for either design inclduing yours.
I do have the original plans that I used for my mini-monitor construction back in 2001 if you wish to e-mail me. My goal was to direct you to the design with the ribbon as it essentially encompasses the older version.
Jim
Colin said:
I agree. The JX 92 is a good midbass and a good fullrange. Perfect for HT I belive where your front channels can have a tweeter (Jim;s choice of the G2) and the center and rears can go without.
I was just wondering alound about a 4" driver that could compete with teh JX92 on all counts save the HF response. I dont know any (the closest driver I know is the Excel mentioned in my earlier post).
The FR125 can be called a poor man's JX92 not that it is that cheap (the FE103 or a 4" Tangband driver might be the real contender for that title) but is still about half the price of the JX92 and can be mated to a WR125 in a 1.5 way.
Colin,
I designed the enclosure to have a reasonable ported box design yet also have a Qtc near 0.707 if sealed. I also took into account the change in volume because of stuffing as well. The difference between a 7.4 or 8 l. is relatively minor and would hardly be noticed by most people.
Jim
I designed the enclosure to have a reasonable ported box design yet also have a Qtc near 0.707 if sealed. I also took into account the change in volume because of stuffing as well. The difference between a 7.4 or 8 l. is relatively minor and would hardly be noticed by most people.
Jim
Jim Griffin said:
I see the master (Jim) also plays full range from time to time...
I also have a supertweeter installed on my VTL.
filtered at 13Khz/12db and added an attenuator, so I can try out different settings.
Tweeter used is the fostex ft7rp...
Indeed with the tweeter there is a sence of "air"
but I must say without the supertweeter it sound so right and no music is missing.
here is a picture of this setup:
http://users.pandora.be/tony.de.lobelle/jx92s with ST.jpg
navin said:
about the beaming:
it depends on the kind of music you play...sometimes a just get a wall of sound and the speakers seemes to be vanished.
But sometimes there is indeed some beaming, but never does this make me want to stop playing music...
I guess no speaker is perfect, but I have never heard music sounding so right as with this speaker...
The supertweeter is more out than in the system...
I think it is a waste using a full range as a midwoofer...it is like putting coca cola in Glenfiddich wisky...it taste good, but you should have taken J Walker red label...
but YMMV...
diytoon said:
I had the same agrument a few posts ago but when I searched my memory bank I cold no find another 4" driver that could produce usefull bass like the JX92 does in 7 liters (0.25 cu. ft).
The Seas 12cm Excel woofer comes close but is 3db less sensitive, but mated to teh T25 Excel tweeter it can be a potent combination in about 0.25-35 (7-10 liters) cu. ft.
So I have begun to believe that the JX92 is really a 4" woofer that can be used as a fullrange (since it has relatively benign atrifcats till 10k) than the other way around (a fullrange used a woofer). Hence for a small system that will be used for watching movies as well as listening to music it is very flexible. Use 3 JX92 fullrange for center and surround and mate it with a tweeter (G2Si,or OW4 are 3 I think would make a lot of sense) for the front (L & R) channels.
Do you know of a better 4" woofer than th JX92 assuming that we dont need it to perform above 3K.
Considering all the new technology in his J6r 6cm driver I wont be surprised if Ted and co are working on a J9r version to repalce the JX92.
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