navin said:
Hmm, I was under the impression that the length of the MLTL was more critical, and the volume requirements would be met if the cross section was not smaller than cone area, but I may be mistaken. Probably some simulation would make it easy to find out.
soongsc said:
I thought that the smaller MLTL has a lenght of about 30" but a cross section of about 30 sq. in. as well. The longer ML TL has a length of 48" right?
navin said:
I think the best length depends upon the driver. Longer ones tune at a lower frequency. I recall it was Martin the mentioned finding the advantages of the MLTL while he was doing some ANSYS analysis. I think you just need to work on it a little. Lots of information is available at his site. http://www.quarter-wave.com/ which is really good for most DIY applications, and lots of explanations on volume and TL length.
Should be a fun project.
navin said:
Hi Hi Navin - Yes, internal dimensions. The 30" is supposed to be the more accurate, the 48 may be more amp dependant.
I'd have thought that the MLTL designs are closely aligned to the driver parameters, so the earlier 92 may not suit, or you may end up with endless fine tuning to get them to work.
Hi Smithie - Just spotted you've also been at work here as well as the Fullrange forum! Thor on the Fullrange runs the JX92 in 8 litre enclosures (ceramic pots) without any form of crossover or BSC, allowing them to roll off naturally. He then brings in a powered sub for the bass. He has commented before that the results were better than the VTL. The JX150s would be ideal for this - there are some specs and designs on Ted's site (www.ejjordan.co.uk/diy/bass) fairly recently put up so you may have missed them. It may be that running the 92s fullrange isn't suitable for your amp/room combination. Thor also commented once that he felt the shallow design of the VTL caused too many reflections and muddied the sound. The triangular enclosure gets rid of the worst of the reflections, ditto Thor's ceramics which (as far as I can gather) taper to a bullet shape inside, somewhat like the Eclipse single driver design (www.eclipse-td.co.uk).
FWIW, the original VTL design could be built to run as a 12 litre closed box (keeping all external dimensions the same and leaving out the internal partitions), though I'm not sure if anyone ever built it that way.
Colin
hi collin,
yeah i get around dont i?
thanks for your info,like i said ive tried this way and that but i cant get on with the vtl design,so will call it aday with that i think.
i will proberly build some seal 8ltr triangle enclosures and use the jx125?150?( more on that in a minute) to do the bass duties with solid state power!
any surgestions regarding inductor size (5mh?) to put on the bass side to blend in with the cross-over free jx92?
ok now a mystery for any detectives out there, i thought the bass drivers i had where jx150,but dimensions dont tally with what collin posted,also doesnt tally up with jx125 yet these must be a ted design....has he been experimenting on the quite,ive had these afew years now,was brought off a guy who told me they was the jx150s....gutted really as it could mean all the parameters are unknown(not that that means much to me anyway)
any clues...will try to post pics on here for viewing!
all the best
smithie
yeah i get around dont i?
thanks for your info,like i said ive tried this way and that but i cant get on with the vtl design,so will call it aday with that i think.
i will proberly build some seal 8ltr triangle enclosures and use the jx125?150?( more on that in a minute) to do the bass duties with solid state power!
any surgestions regarding inductor size (5mh?) to put on the bass side to blend in with the cross-over free jx92?
ok now a mystery for any detectives out there, i thought the bass drivers i had where jx150,but dimensions dont tally with what collin posted,also doesnt tally up with jx125 yet these must be a ted design....has he been experimenting on the quite,ive had these afew years now,was brought off a guy who told me they was the jx150s....gutted really as it could mean all the parameters are unknown(not that that means much to me anyway)
any clues...will try to post pics on here for viewing!
all the best
smithie
Hi Smithie
What do the drivers look like? There was an earlier bass driver, J125, which had similar cone but a cast aluminium chassis, an inch or two wider diameter than the JX125 (poss deeper as well). It was used in the old Townsend Glastonbury speaker. Still very good and might match your 92 better. As far as I can remember, I think it had a silver surround rather than black, but this may have changed during production.
Ref inductor, there's one mentioned on Ted's site for rolling off a bass unit to the JX92s when using them in a 3 litre cabinet. That would probably do as a starter. (I forget if it is in the 92 or on the JX53 page of his site).
What do the drivers look like? There was an earlier bass driver, J125, which had similar cone but a cast aluminium chassis, an inch or two wider diameter than the JX125 (poss deeper as well). It was used in the old Townsend Glastonbury speaker. Still very good and might match your 92 better. As far as I can remember, I think it had a silver surround rather than black, but this may have changed during production.
Ref inductor, there's one mentioned on Ted's site for rolling off a bass unit to the JX92s when using them in a 3 litre cabinet. That would probably do as a starter. (I forget if it is in the 92 or on the JX53 page of his site).
width of outter frame is..211mm
cone is 123 minus rubber surround.
depth is.. roughly 105mm.
thats all i have......
thanks
smithie
cone is 123 minus rubber surround.
depth is.. roughly 105mm.
thats all i have......
thanks
smithie
I think they are the Glastonbury drivers, possibly reconed. Ted's original drivers had a sort of glue spot int he centre where the centre suspension attached. He had these on early JX125s too, then modified them to have the centre 'dome' covering the glue spot. These look like the newer cones in the original chassis.
Both types of 125 work fine in a sealed enclosure, between 25 and 50 litre size. If the parameters are in question, this is probably the safest way to go. I use my JX125s in a 35-ish litre sealed enclosure, which gets to 45Hz in my room.
Both types of 125 work fine in a sealed enclosure, between 25 and 50 litre size. If the parameters are in question, this is probably the safest way to go. I use my JX125s in a 35-ish litre sealed enclosure, which gets to 45Hz in my room.
hi collin
YOUR THE MAN!
thanks for that,was getting worried there as i was thinking that they wouldnt be up to the job,the real deal.
so ill do as you say,aim for a 30-35 ltr sealed enclosure,45hz is respectable enough for me.
many thanks
smithie
YOUR THE MAN!
thanks for that,was getting worried there as i was thinking that they wouldnt be up to the job,the real deal.
so ill do as you say,aim for a 30-35 ltr sealed enclosure,45hz is respectable enough for me.
many thanks
smithie
Glad I was able to help. The 35L boxed gives a Q of about 0.7, which should match well with an 8L JX92 enclosure. Let us know how you get on.
hi collin
i shall let you know the out come...if it ever gets warmer and stops raining so i can get on to build them.
on another note....you obviously know ted well,chat often,then maybe you can shed some light on a reply i got from mj acoustics regarding there similar looking vtl desined speaker...quote...
"I would just like to point out that our speakers are made for us by Ted Jordon, but they are not the similar looking JX 92's. Our collaboration with Ted led us onto a higher specification driver than the JX 92's and after much development, MJ Acoustics had their own spec driver. The cone surface and the molecular technology are the same, thus the appearance is similar."
if this is a better spec driver then the jx92s then is ted thinking of bringing out a newer version of the 92...anthing in the pipeline?
seems weird that he would build a better driver for someone else then the one he sells himself...just curious!
all the best
smithie
i shall let you know the out come...if it ever gets warmer and stops raining so i can get on to build them.
on another note....you obviously know ted well,chat often,then maybe you can shed some light on a reply i got from mj acoustics regarding there similar looking vtl desined speaker...quote...
"I would just like to point out that our speakers are made for us by Ted Jordon, but they are not the similar looking JX 92's. Our collaboration with Ted led us onto a higher specification driver than the JX 92's and after much development, MJ Acoustics had their own spec driver. The cone surface and the molecular technology are the same, thus the appearance is similar."
if this is a better spec driver then the jx92s then is ted thinking of bringing out a newer version of the 92...anthing in the pipeline?
seems weird that he would build a better driver for someone else then the one he sells himself...just curious!
all the best
smithie
Hi - I had a look at the MJ Acoustics page (http://www.mjacoustics.co.uk/MJ_Acoustics/Product_html/S1R.htm) and it certainly looks like the JX92 and VTL combination. I know Ted is working closely with them to produce subs for his own systems and it's possible he produces a customised JX92 for their particular application. If that's the case, it may be too specifically tailored for general use or just restricted by commercial agreement. No new JX92 around that I know of - his next driver is an updated JX53, pushing the resonance of that driver to 75Hz or so.
8 litre closed box for the 92 gives flat to 100Hz so should reach 80Hz ok. Personally think the JX125 works best as a bass driver as it gets a bit rough about 2k or so.
Colin
8 litre closed box for the 92 gives flat to 100Hz so should reach 80Hz ok. Personally think the JX125 works best as a bass driver as it gets a bit rough about 2k or so.
Colin
hi collin
thanks for the info,was just curious thats all,those mj versions look nice....£2000 nice im not so sure,but would lve to hear them all the same!
rain held off long enough for me to start work on the new enclosures....so ive started and ill finish...need to get some more wood first!
got a old pioneer 400 that might do for the time being to power the jx125s,still not sure of a value of the inductor for rolling off at 80 ish hz,i think ive got a old incar active xover that i could experiment with,i remember it having the xover points just dont think its a 1st order slope.
i know you can by sub moduals(self containd panel with amps,xover etc) so that may be a better solution in the end as i could build that into the enclosure, anyone had any experience with these things?
ill post some pics as and when i get some real progress going!
thats intresting about the jx53s,dont surpose teds upped the sensitivity also? do love those drivers,so wished i had kept mine!
all the best
smithie
thanks for the info,was just curious thats all,those mj versions look nice....£2000 nice im not so sure,but would lve to hear them all the same!
rain held off long enough for me to start work on the new enclosures....so ive started and ill finish...need to get some more wood first!
got a old pioneer 400 that might do for the time being to power the jx125s,still not sure of a value of the inductor for rolling off at 80 ish hz,i think ive got a old incar active xover that i could experiment with,i remember it having the xover points just dont think its a 1st order slope.
i know you can by sub moduals(self containd panel with amps,xover etc) so that may be a better solution in the end as i could build that into the enclosure, anyone had any experience with these things?
ill post some pics as and when i get some real progress going!
thats intresting about the jx53s,dont surpose teds upped the sensitivity also? do love those drivers,so wished i had kept mine!
all the best
smithie
Colin said:
colin, is there a place i can see the Thor design. Where is this fullrange forum.
the eclipse site was forbidden for entry. is it down?
HI
I GOT THIS RESPONSE FROM FALCON CONCERNING A INDUCTOR VALVE FOR MY PLAN REGARDING THE 8LTR JX92 ENCLOSURE MATED TO THE JX125 BASS ENCLOSURE..
I am afraid that it is not possible to devise a satisfactory passive crossover for such a low frequency. The only way is to use active such as the Basset.
The values would be so large that the resistance would be far too high and the impedance of the bass units is varying - it is close to the resonances of the existing and the new bass units - that you are trying to design into a fast varying impedance which is not really possible.
M. Jones
Falcon
I DONT REALLY UNDERSTAND WHATS BEING SAID HERE OTHER THEN I HAVE TO GO ACTIVE OR ELSE THIS PLAN,IM STUFFED
AINT NOTHING EVER EASY...
SMITHIE
I GOT THIS RESPONSE FROM FALCON CONCERNING A INDUCTOR VALVE FOR MY PLAN REGARDING THE 8LTR JX92 ENCLOSURE MATED TO THE JX125 BASS ENCLOSURE..
I am afraid that it is not possible to devise a satisfactory passive crossover for such a low frequency. The only way is to use active such as the Basset.
The values would be so large that the resistance would be far too high and the impedance of the bass units is varying - it is close to the resonances of the existing and the new bass units - that you are trying to design into a fast varying impedance which is not really possible.
M. Jones
Falcon
I DONT REALLY UNDERSTAND WHATS BEING SAID HERE OTHER THEN I HAVE TO GO ACTIVE OR ELSE THIS PLAN,IM STUFFED
AINT NOTHING EVER EASY...
SMITHIE
navin said:
http://fullrangedriver.com/forum/
I don't know whether James has his forum archives accessible yet (where most of the Thor stuff would be)
dave
Navin - try .com rather than .co.uk for eclipse, everything seems ot be routed there now. Or look on Google, the speakers seem to be cropping up all over the place. (They even do a smaller desktop version now as high end computer speakers.)
Smithie - I'd try the inductor suggested by Ted and not worry about Falcon. Their Basset is a complete design consisting of amp and KEF drivers (or the original design had KEF, may be different now) and the enclosure was huge. (It was used as a window seat.) Ted's value is aiming at around 100Hz and is a very shallow slope - you could face the drivers down to the floor for a bit of added rolloff.
Try the inductor route for now and then if the results look promising, you could try adding a filtered Gainclone to the bass. I'm sure somebody on the Chipamp forum could advise a passive filter for the input of the bass amp.
From what I've read on the various forums, the passive approach for the sats works well but it does improve with filtering and a proper active crossover. Gets complicated then and, of course, expensive. (Why does this hobby so often get expensive just as things start to get really interesting?) If you go that route sometime in the future, there are a few sites out there who sell active crossover kits.
If Falcon are still a bit sniffy about selling you a passive inductor or two, try Wilmslow. I've found them very helpful.
There will be more people here better able to advise when going active. (I haven't done it yet, still running my JX92s from a 15w Naim amp.)
Hope this helps.
Colin
Smithie - I'd try the inductor suggested by Ted and not worry about Falcon. Their Basset is a complete design consisting of amp and KEF drivers (or the original design had KEF, may be different now) and the enclosure was huge. (It was used as a window seat.) Ted's value is aiming at around 100Hz and is a very shallow slope - you could face the drivers down to the floor for a bit of added rolloff.
Try the inductor route for now and then if the results look promising, you could try adding a filtered Gainclone to the bass. I'm sure somebody on the Chipamp forum could advise a passive filter for the input of the bass amp.
From what I've read on the various forums, the passive approach for the sats works well but it does improve with filtering and a proper active crossover. Gets complicated then and, of course, expensive. (Why does this hobby so often get expensive just as things start to get really interesting?) If you go that route sometime in the future, there are a few sites out there who sell active crossover kits.
If Falcon are still a bit sniffy about selling you a passive inductor or two, try Wilmslow. I've found them very helpful.
There will be more people here better able to advise when going active. (I haven't done it yet, still running my JX92s from a 15w Naim amp.)
Hope this helps.
Colin
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