Landroval said:
I'd still recommend trying the JX92 on its own before adding anything. One of the best tweeters around is the JX53 (the new model should be even better) and in this context, it gives the ability to cross between the two units at around 500Hz, rather than the image-disrupting 2kHz and above that conventional tweeters use. However, having tried this, I still think the image integrates better using the 92 on its own. It already measures up to 20kHz and I think you lose more than you gain by adopting a second driver to gain a few extra kHz.
Colin
Colin said:
I also tend to agree.
But a recent trip to a local recording studio let me realize some recording engineers do not care about image and depth. The speakers they used sound neutral if you don't try to pin point imaging. So choices depend on how people listen to music. Sounding good doesn't mean realistic. There are lots of people that don't have much access to variety of liver performances with good equipment, and so may be limited having to live reference.
Colin said:
But 500Hz is right in the middle of the human voice. I'd prefer to cross higher or lower.
Yep, the lower the better. The new unit should allow a crossover around 150Hz, though the JX92's abilities are perhaps wasted as just a low-mid/bass unit.
Colin said:
Thanks for advice.
I actually have had the JX92S in GM MLTL-48" for about two months now and I've listened to it with and without a simple BSC (4,7ohm + 1,1mH). The imaging and level of detail is better than with my Seas 6,5" coaxial bookshelf speakers, but somehow the Jordans are not as pleasing to the ear. They also lack some of the impact of the bigger 6,5" driver and the highs are not as clear as with the separate metal dome tweeters.
Hmm, I just removed the BSC, and it made the sound a lot clearer, but now it's shouting a little.
Maybe I should try to play with stuffing (more? less?) before I do any conclusions.
Toe in your Jordans a litlle bit more. That makes them easier for your ears. On the other hand you will lose some of the crispiness. Also the imaging might become a bit too accurate and soundstage might become a bit smaller. Compromises... 
Aha, another 48-MLTL convert.
I use this system with no BSC - I haven't found any need for it. The harshness is because the 92's have a rising HF response to compensate for the toe-in. This should be around 60 degrees (there's more about it on the Jordan site at www.ejjordan.co.uk/systems ).
As DIAR says, its all about compromises. You can tune the sound by turning the enclosures, although I find if you turn them out to the more usual 45 degrees, the depth of soundstage suffers a little.
Colin
I use this system with no BSC - I haven't found any need for it. The harshness is because the 92's have a rising HF response to compensate for the toe-in. This should be around 60 degrees (there's more about it on the Jordan site at www.ejjordan.co.uk/systems ).
As DIAR says, its all about compromises. You can tune the sound by turning the enclosures, although I find if you turn them out to the more usual 45 degrees, the depth of soundstage suffers a little.
Colin
With and the Jordans, you really need the best componenets to bring out the potential. Solen Heptalitz for inductors are what many people choose, I currently use Alpha Core foil inductors. Once you get the BSC theoretically right, then change the components.
Proper caps will adjust the power phase in some designs resulting in more coherent sound, but testing and analysis is required.
Proper caps will adjust the power phase in some designs resulting in more coherent sound, but testing and analysis is required.
Landroval said:
You mentioned the stuffing on an earlier post. My MLTL's have stuffing from just below the driver to the top, using BAF (bonded acetate fibre - not sure what the USA trade product equiv is, maybe Acoustistuff). It's not compressed and seems to work fine. Note, though, that mine are the triangular versions, so will suffer less from reflections.
If your units are shouting a little, maybe they are slightly overstuffed and removing some would balance out the sound.
Hope this helps.
Colin
Landroval,
4,7 ohms is quite much for BSC. If you haven't tried anything else than 4,7 ohms and no BSC at all, you could try some smaller resistor values.
Also, smaller inductor may or may not sound better with smaller resistor.
4,7 ohms is quite much for BSC. If you haven't tried anything else than 4,7 ohms and no BSC at all, you could try some smaller resistor values.
Also, smaller inductor may or may not sound better with smaller resistor.
Landroval said:
Yep 😀
I now have 1,5 mH Alpha-Core copper foil inductor and Mills resistors. They are so much better than cheap ceramic resistors and cheap mundorf inductor. I have tried several resistor values and different kinds of capacitors but I always end up unplugging the filter. My room helps the bass region so I don't need the filter that much.
For some reason I sometimes find Jordans more or less fatiguing.
I am planning upgrade my speakers. I'm concidering a few 8" inch fullrange drivers/ Zu Druid speakers.
At the moment my Jordans cross atleast 1 m in front of listening place. I also have added tweeters on top of the speakers and aimed them up. The cut off frequency is about 14 kHz. The result is quite pleasing.
DIAR said:
The Jordans are very revealing, any difficiency in the upstream will show up. So it is important to make sure you are using very good equipmenr. Some electostatic speakers do the same thing.
For resistors, IMO it's best to use a much higer rating than what your speakers are rated to do. Most resistors are rated not on signal quality porformance but on how hot it can get before buring. You want thick resistive wire to keep the cross section as close to you inductor and cable as possible.
Landroval said:
Try 3.3 ohms or lower for the BSC. The problem with the Jordan it seem that to compensate for the off axis roll off they response rises.
One way out would be to use a tweeter above 5K. Many have suggested ribbon tweeters with high order slopes but this defeats the purpose of using a fullrange and might affect the coherence assoiciated with full range drivers.Then there is the matter of interpolar interference and phase anomalities associtaed with this concept.
Colin said:
Does it not sound a bit thin without BSC or do you have some bass reinforecement compensating for this?
I have been looking at many drivers that will work in a 7-10liter box and produce good sound between 100Hz and 20kHz. I think in this regard the JX92 is one of the best. If anyone has other contenders (Fostex 108 or 127 or the FR 125) please let me know.
navin said:
No bass reinforcement necessary. GM's 48" MLTL design (www.ejjordan.co.uk/diy) gives a very satisfying sound from this driver with a richness to the mid and bass which is very good on acoustic and orchestral work. Despite the operating principle, they are actually less resonant than my JX125's in a sealed enclosure.
Because of the triangular design, I'm able to use them close to the rear wall and the shape gives the correct toe-in.
The 92s are very revealing so I think the amp and source needs to match. The Gainclone is probably a good fit (as the Konus speaker, which is similar to the Jordan VTL, was designed to work with the Gaincard). I've yet to try this and at the moment the speakers are running from Naim amplification and source components (FM and CD).
I've heard the 92s in the Jordan recommended 8 litre reflex enclosure and they do benefit from BSC, as suggested on the Jordan site.
Colin
Colin said:
Can you please post a pic of your enclosure?
I intend to drive the JX92 using a Marantz SR 7000 HT/AV receiver. It will do duty as a audio as well as HT/AV speaker.
For the bass I intend to use a audio concepts sub in a sealed or aperiodic box.
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