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Mike Bates
03-25-2004, 09:42 PM
Anyone here horn loading these? What kind of upper end extension are you getting with what horn/back chamber? How do they sound? Don't care about Mcbean simulations ect.. no indicator of highend response.

pangea
03-27-2004, 09:12 AM
Originally posted by Mike Bates
Anyone here horn loading these? What kind of upper end extension are you getting with what horn/back chamber? How do they sound? Don't care about Mcbean simulations ect.. no indicator of highend response.

Hi Mike!

I found these tech-notes the other day, prhaps they can be of some help.

http://www.jblpro.com/pub/technote/tn_v1n24.pdf

BR
Roland

Mike Bates
03-27-2004, 10:26 AM
Thanks, I missed that one. From the looks of that article I probably should stick with the 2123.

Regards

tomp787
03-29-2004, 10:29 AM
Hello,

there is also a newer 10 inch called the 2251. It has a neo magnet and "differential drive" magnetic structure. There is a tech note about it that I can look for if you can't find it.

How did you choose your rear chamber size? The Dr Edgar articles talk about hyp-exp rear chambers but not tractrix. I have some Edgar 150Hz rectangular tractrix and 2123/2012/2251 but I need to make a rear chamber to use them.

I have a single 2012 and 2251 you can perhaps borrow. Send me a PM if you are interested and we can talk.

Tom

pangea
03-29-2004, 11:07 AM
Originally posted by tomp787
Hello,

...How did you choose your rear chamber size? The Dr Edgar articles talk about hyp-exp rear chambers but not tractrix. I have some Edgar 150Hz rectangular tractrix and 2123/2012/2251 but I need to make a rear chamber to use them...


Tom

Hi!

You don't happen to have some pics/plans/measurements on those horns?

Which driver is it intended for?

I'm not sure but I think I've read somewhere, the rear chamber for the 2123 has to be small (1 L), whatever that is, in your neck of the woods. :D

BR
Roland

Mike Bates
03-30-2004, 04:23 PM
Thanks, I could not find info on the 2251 at jblpro.com.

Rear chamber size was simulated in McBean software and a 9 liter chamber was built. The driiver takes up 3, so I kept on taking away/ adding space for the widest flatest, response. One liter is where it's at (4 liter minus the driver).

Thanks for the offer to try the drivers, are you near Ohio?




Originally posted by tomp787
Hello,

there is also a newer 10 inch called the 2251. It has a neo magnet and "differential drive" magnetic structure. There is a tech note about it that I can look for if you can't find it.

How did you choose your rear chamber size? The Dr Edgar articles talk about hyp-exp rear chambers but not tractrix. I have some Edgar 150Hz rectangular tractrix and 2123/2012/2251 but I need to make a rear chamber to use them.

I have a single 2012 and 2251 you can perhaps borrow. Send me a PM if you are interested and we can talk.

Tom

tomp787
03-31-2004, 12:46 PM
Hello Mike,

Info on the 2251 can be found in tech note volume 1 number23. The T/S parameters are in the T/S file. The driver is used in the 4348 monitor which has some info on audioheritage and other information on jblproservice.com.

I'm in Texas, but I have all the original boxes so I think the drivers would ship ok. The 2251 is lighter than 2123, the 2012 is heavier than 2123.


Hello Roland,

>You don't happen to have some >pics/plans/measurements on those >horns?
>BR
>Roland

My Edgar tractrix low-mid horn has a 6 x6 inch throat. The mouth is 26 x 18 inches and the length is 16 inches. It appears to be constructed as shown in the "Edgar Midrange Horn" article which I believe is on the www somewhere.

Regards, Tom