While in Japan, I design a 3 way full horn speaker based on the excellent work of Bruce Edgar for the calculation of the expansion but with only one 90 degree bending.
The difficulty is that it is impossible to achieve good matching with driver (JBL 2451) if the mass roll off frequency is not around 600 hz. This is the main reason why I used the JBL E120 that gives me a flat response up to around that frequency.
I have enjoyed the system for the past 8 years but I am now looking for a driver with a lower FC (presently there is no response below 60 hz) so that I can design an horn that could go lower (ideally 45 hz) but still retain the higher roll off.
The ideal TS parameters would be the following:
FC : 35 to 45 hz
VAS : around 70
Qe : lower than 0.12
Anyone has a candidate for that? I will also post pictures of the present speaker
Thanks for your help
Noe from Singapore
The difficulty is that it is impossible to achieve good matching with driver (JBL 2451) if the mass roll off frequency is not around 600 hz. This is the main reason why I used the JBL E120 that gives me a flat response up to around that frequency.
I have enjoyed the system for the past 8 years but I am now looking for a driver with a lower FC (presently there is no response below 60 hz) so that I can design an horn that could go lower (ideally 45 hz) but still retain the higher roll off.
The ideal TS parameters would be the following:
FC : 35 to 45 hz
VAS : around 70
Qe : lower than 0.12
Anyone has a candidate for that? I will also post pictures of the present speaker
Thanks for your help
Noe from Singapore
Qes of .12 is extremely low and will take a massive motor. It can be done, but would be pricey. As far as off the shelf goes the TD10M is close in Fs and Vas although Qes is higher. At Qes of .26 though it still has quit a big of motor strength. http://aespeakers.com/shop/catalog/product_info.php?cPath=23&products_id=64
Depending on what you need for Xmax, a shorter flat wire copper coil could get Qes down close to that range. A larger diameter coil could accomplish it quite easily.
John
Depending on what you need for Xmax, a shorter flat wire copper coil could get Qes down close to that range. A larger diameter coil could accomplish it quite easily.
John
Dear Peter and John,
Thanks for your help there but the most important for me is to have a driver with a Qes around 0.12, for horn loading, it is by far the most important factor if we want to have control over the horn and make the response as flat as possible.
I have tried to find a driver like that for quite some time but it seems like it is impossible to find one with a low FC.
I was browsing the internet today.. I had some free time during lunch ! and found something interesting in the website of Fertin and Supravox.
Interestingly, they both use field coil magnets and this seems to play the trip. I have called Fertin and send an email but no reply !
Anyone has ever used a field coil speaker in a front loaded speaker before?
Here is a picture of my current 3 way horn speakers ! Now is time for the V2 of those.
Cheers
Thanks for your help there but the most important for me is to have a driver with a Qes around 0.12, for horn loading, it is by far the most important factor if we want to have control over the horn and make the response as flat as possible.
I have tried to find a driver like that for quite some time but it seems like it is impossible to find one with a low FC.
I was browsing the internet today.. I had some free time during lunch ! and found something interesting in the website of Fertin and Supravox.
Interestingly, they both use field coil magnets and this seems to play the trip. I have called Fertin and send an email but no reply !
Anyone has ever used a field coil speaker in a front loaded speaker before?
Here is a picture of my current 3 way horn speakers ! Now is time for the V2 of those.
Cheers
noesaglio said:
I did think about those too, so I will rspond to that
if they would do then a EMS might too
http://www.emspeaker.fr/home_ger.html
Precision Devices (UK) have one or two heavy duty woofers with similar specs
GreatPlainsAudio ought to have good woofers fore horns
And GOTO, if you have that kind of money
But its not clear to me which size woofer you need
hi Tinitus,
I had heard of Great Plains and they have some fantastic speakers but like Goto the price is also stratospheric
EMS looks like a very good lead and it is also easier to find 12 inch speakers that have a lower Qes and a not too low FS. I will definitely post an email to them to see what they can propose.
I have run some simulations with 15 inch units and it is always hard to get them to sing above 300 hz. The matting with a driver becomes then difficult.
Thanks for the lead ! I will keep you posted of the result of the enquiry.
Attached is another picture of the speaker
I had heard of Great Plains and they have some fantastic speakers but like Goto the price is also stratospheric
EMS looks like a very good lead and it is also easier to find 12 inch speakers that have a lower Qes and a not too low FS. I will definitely post an email to them to see what they can propose.
I have run some simulations with 15 inch units and it is always hard to get them to sing above 300 hz. The matting with a driver becomes then difficult.
Thanks for the lead ! I will keep you posted of the result of the enquiry.
Attached is another picture of the speaker
noesaglio said:hi Tinitus,
I had heard of Great Plains and they have some fantastic speakers but like Goto the price is also stratospheric
EMS looks like a very good lead and it is also easier to find 12 inch speakers that have a lower Qes and a not too low FS. I will definitely post an email to them to see what they can propose.
Hi
I agree, Goto is rediciously expencive
GreatPlains I reckon is not that far from EMS
I got a price of 750EUR from EMS fore a pair
You could also look at AESpeakers(USA), pretty nice too
All sizes in the H-series Lambda have very low Qts
I reckon its not relevant when wanting good mids, but some of the Peerless XLS an XXLS sub driver have very low Qts
The eighteensound could make the trick but I really want a stronger magnet and a lower FC so that I would not need a Sub !
Thanks for the contact of EMS, the guys are great and they can modify their driver to make one that could be perfectlly suitable for this. I would need an Xmax of around 3. I think this could be the best solution and the field would allow to have a very strong magnet.
For the construction, the previous one was built using resonant woods which I prefer to stiff construction with Asphalt lining. Tested both in Japan and definitely prefer this.
This time I would like to use the double top building that guitar builders are starting to use. Anyone has experience with this?
For the picture, I had to compress it but here it is !
Cheers
Thanks for the contact of EMS, the guys are great and they can modify their driver to make one that could be perfectlly suitable for this. I would need an Xmax of around 3. I think this could be the best solution and the field would allow to have a very strong magnet.
For the construction, the previous one was built using resonant woods which I prefer to stiff construction with Asphalt lining. Tested both in Japan and definitely prefer this.
This time I would like to use the double top building that guitar builders are starting to use. Anyone has experience with this?
For the picture, I had to compress it but here it is !
Cheers
Attachments
Hi Noe,
Very nice looking horns!
Above I suggested the Beyma Nd drivers and obviously, the decision is yours, but if it was me, then I would consider giving up trying to let a single driver/horn combo cover the bandwidth you are chasing.
I myself have large, straight 29 Hz bass horns loading with double 15" low Qt, high EBP drivers, and even though their mass roll of is at, say 380 Hz, they sound better when crossed over below 200 Hz.
If you for instanse let a tapped horn sub (or two) cover up to 60-80 Hz, then you will have a much easier task having a shorter, straight horn low-mid horn reaching 600 Hz. I suspect that a smaller straight horn will sound more open and clear than a long folded one in the 200-600 Hz range.
I do not think this would be more expensive although you will need an aditional set of horns, because you will probably save quite a bit of money by not needing a custom made ultra strong, low fs driver.
Just a thought....
Best regards
Peter
Very nice looking horns!
Above I suggested the Beyma Nd drivers and obviously, the decision is yours, but if it was me, then I would consider giving up trying to let a single driver/horn combo cover the bandwidth you are chasing.
I myself have large, straight 29 Hz bass horns loading with double 15" low Qt, high EBP drivers, and even though their mass roll of is at, say 380 Hz, they sound better when crossed over below 200 Hz.
If you for instanse let a tapped horn sub (or two) cover up to 60-80 Hz, then you will have a much easier task having a shorter, straight horn low-mid horn reaching 600 Hz. I suspect that a smaller straight horn will sound more open and clear than a long folded one in the 200-600 Hz range.
I do not think this would be more expensive although you will need an aditional set of horns, because you will probably save quite a bit of money by not needing a custom made ultra strong, low fs driver.
Just a thought....
Best regards
Peter
It would be using the 12 field coil version. I am waiting for their reply on this. It seems also that one of the trick could be to remove the surround. That would lighten the membrane and therefore the Qes !
I am waiting for their reply.
For the TAD 1201, I had looked at this driver when I started the design of the present speaker but even in Japan they were very difficult to source and are mostly made to order. I saw one on Ebay some for sale but stayed with the E120. The importance is to have a high mass roll off frequency because even if the calculated one is above 600 Hz, in reality, there is not enough output above 500 Hz.
Think that the EMS and the Fertin familly (she is the daugher of Michel Fertin!) are the right ones to design this impossible unit.
For the moment, I am using a velodyne DD18 below 50Hz and I really want to get it out and also simplify my system.
Here is another picture of the horn.
Cheers
I am waiting for their reply.
For the TAD 1201, I had looked at this driver when I started the design of the present speaker but even in Japan they were very difficult to source and are mostly made to order. I saw one on Ebay some for sale but stayed with the E120. The importance is to have a high mass roll off frequency because even if the calculated one is above 600 Hz, in reality, there is not enough output above 500 Hz.
Think that the EMS and the Fertin familly (she is the daugher of Michel Fertin!) are the right ones to design this impossible unit.
For the moment, I am using a velodyne DD18 below 50Hz and I really want to get it out and also simplify my system.
Here is another picture of the horn.
Cheers
Attachments
If you want to stay with 3-way you might want to lower the crossover point between the bass and mid-frequency drivers.
I don't think you will damage the 2451 in a home environment if you go down to e.g. 400Hz. That would make it a little easier to find a suitable low-frequency driver.
You could also look at other mid-frequency drivers like the JBL 2482 or preferrably the JBL 2490.
Did i see a JBL 2405 there? In that case you will have an issue with both the 2482 and the 2490, so....
I have played a bit with the thoughts of a 3-way horn system around the JBL 2490. Maybe with TAD 1601/1801 at the bottom and TAD 2001 or JBL 2407/8 at the top end.
In the meantime I will rebuild my 4-ways with JBL 2245 in a ported enclosure at the bottom. TAD 1201 in a mid-bass horn. JBL 2435 in a HF horn and JBL 077 at the top.
At present I have the 2245's and the 077's. JBL 2202 in a closed box for mid-bass and JBL LE85 at HF.
I don't think you will damage the 2451 in a home environment if you go down to e.g. 400Hz. That would make it a little easier to find a suitable low-frequency driver.
You could also look at other mid-frequency drivers like the JBL 2482 or preferrably the JBL 2490.
Did i see a JBL 2405 there? In that case you will have an issue with both the 2482 and the 2490, so....
I have played a bit with the thoughts of a 3-way horn system around the JBL 2490. Maybe with TAD 1601/1801 at the bottom and TAD 2001 or JBL 2407/8 at the top end.
In the meantime I will rebuild my 4-ways with JBL 2245 in a ported enclosure at the bottom. TAD 1201 in a mid-bass horn. JBL 2435 in a HF horn and JBL 077 at the top.
At present I have the 2245's and the 077's. JBL 2202 in a closed box for mid-bass and JBL LE85 at HF.
noesaglio said:
What you are looking for with the Vas and Fs is not going to be too practical unless you want small driver. Getting a low Fs requires soft suspension. Getting low Vas requires stiff suspension. You're going to really need to pick one or the other. The only other way would be with a stiff suspension and a huge amount of mass. Then you're going to need enormous amounts of motor to get the low Q you are looking for.
If you don't worry about high Vas, this can be done.
Fs: 27hz
Qms: 3.9
Vas: 519L
Cms: .5mm/N
Mms: 70g
Xmax: 6mm
Sd: 855sqcm
Qes: .16
Re: 6.6
Le: .2mH
Bl: 22Tm
Qts: .15
1w/1m: 100dB
Shortening Xmax to only 2-3mm could get the Qes down to about .135.
John
EMS...ElectroMagneticSpeaker
Looks like a sensible choice fore certain kinds of enthusiasts
Some say that once you have listened to a field coil driver, nothing else will do
But I suppose that not all field coil drivers are equally good, as with every other driver
http://www.emspeaker.fr/pdf/Courbes_12EX.pdf
Looks like a sensible choice fore certain kinds of enthusiasts
Some say that once you have listened to a field coil driver, nothing else will do
But I suppose that not all field coil drivers are equally good, as with every other driver
http://www.emspeaker.fr/pdf/Courbes_12EX.pdf
Attachments
I am using the following drivers and crossover points:
DD18: no low pass, 48 hz high pass, 48 db
60 Hz horn with JBLE120: no low pass, 450 hz high pass, 6 db
JBL2451+JBL2353 Bi Radial : 450 low pass, 24db, no high pass
JBL2405 : 8 K low pass, 24 db, no high pass
The crossover used is the behringer 2496 modified as per the excelent instructions availables at http://www.dcx2496.fr
In the past, I actually had a system built on the JBL2490 and the horn was going down to around 290 hz. That the system the present one is replacing.
The main reason why I ditch this is because the most important info is for me betweeen 60 and 500 hz and I do not really like to have crossovers in that region. When I changed it to this one, it made a tremendous difference. I will look if I can find some pictures of the old system.
Now I listen to a lot of Piano and the JBL2490 was not as much involving as is this E120 loaded 60 horn. The JBL2490 was developed for the theater (part of the system 500 or 5000 if I remenber) and is not as delicate as the other ranges from JBL. I just read that JBL is launching in Japan a new version of the 2450 called 2450SL. It is supposed to go higher than the previous driver. Available on hino-audio.co.jp. Attached is the datasheet
It is true that field speakers are really amazing. They sound so dynamic and effortless.
Cheers
DD18: no low pass, 48 hz high pass, 48 db
60 Hz horn with JBLE120: no low pass, 450 hz high pass, 6 db
JBL2451+JBL2353 Bi Radial : 450 low pass, 24db, no high pass
JBL2405 : 8 K low pass, 24 db, no high pass
The crossover used is the behringer 2496 modified as per the excelent instructions availables at http://www.dcx2496.fr
In the past, I actually had a system built on the JBL2490 and the horn was going down to around 290 hz. That the system the present one is replacing.
The main reason why I ditch this is because the most important info is for me betweeen 60 and 500 hz and I do not really like to have crossovers in that region. When I changed it to this one, it made a tremendous difference. I will look if I can find some pictures of the old system.
Now I listen to a lot of Piano and the JBL2490 was not as much involving as is this E120 loaded 60 horn. The JBL2490 was developed for the theater (part of the system 500 or 5000 if I remenber) and is not as delicate as the other ranges from JBL. I just read that JBL is launching in Japan a new version of the 2450 called 2450SL. It is supposed to go higher than the previous driver. Available on hino-audio.co.jp. Attached is the datasheet
It is true that field speakers are really amazing. They sound so dynamic and effortless.
Cheers
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.