Beamwidth Control

[Zilch]

Looks like JBL's got it figured in newest offerings:

http://www.jblpro.com/vrx/pdf/JBL.VRX932LA.pdf

[Guido]

What the heck is a 2407J ?

And if there is a "J" there should be a "H" too.

[pelly3s]

the 2407 is a new n/dym driver i think that this is the first box its being used in. I have yet to see it I should be getting a couple soon at my shop on loan from my rep. once i get one of the boxes in it will come apart and i'll take pictures of the driver.

[Zilch]

Transducer list shows 2406 ($133) and 2407 ($199). What are they?

http://www.jblproservice.com/pdf/Transducer%20List/04%20Transducer%20List.pdf

2406H-1: http://www.jblproservice.com/pdf/MPro%20Series/MP412.pdf

2407H: http://www.jblproservice.com/pdf/AE%20Series/AM4200,95-WH.pdf

[stevem]

the 2407 is a new n/dym driver i think that this is the first box its being used in. I have yet to see it I should be getting a couple soon at my shop on loan from my rep. once i get one of the boxes in it will come apart and i'll take pictures of the driver.

Did you ever get a look at the 2407? Is there any additional information available? Thanks.

[pelly3s]

i didnt take it apart all i know is its a thread on ring radiator i can try to get some info shortly

[Jan Daugaard]

Hi Pelly3s,

I'm planning to use the 2407H with the 2346 horn (= the Everest horn) and would appreciate any information about this new compression driver you can provide.

[Zilch]

2407H is a 1" thread-throat neodymium magnet ring radiator compression tweeter, typically crossed above 2.5 kHz (2.7 kHz, 2.8 kHz) in JBL's use of it. Diaphragm is 1.75", presumably titanium.

Response is to 20 kHz, but competitive specsmanship mandates a claimed "range" to 23 kHz on PT waveguides.

Requires a horn. I'd try the 85° conical OASR and the cheap 1" PT-F95 with it. Both have the requisite thread-on throats.

http://www.jblpro.com/pub/cspels/CBT4%205-5-03.pdf

Tomp787 suggests the DDS eng1-90 horn works well with it, too.

A miniature H3100 controlled directivity waveguide for it would be the bee's knees.... ;)

[tomp787]

Hello,

Be aware that the oasr has a 7/8 inch throat while the bms 4540 has a 1 inch throat. Be sure your driver has a 7/8 throat, I wish I did before I bought the oasr. Perhaps the 2407 throat size is 7/8 inch but I suggest checking before purchasing it to use with the oasr.

I have some data on the bms/oasr if someone needs it. The bms 4540 sounded much better with the dds horn which has a 1 inch throat. If anyone needs a single oasr I'm sure we can trade.

Tom

[Zilch]

The OASR horn is used in JBL products on 2412H, 2418H-1, and 2426H, all 1" throat drivers.

Examining the horn throat closely, I see that the aperture itself may in fact be 7/8" diameter; it appears smaller than that of 2370A, for example. I don't have the proper tools to actually measure it.

Someone also mentioned that it is aluminum. Although the throat has an aluminum threaded insert moulded in, the ones I have are the standard JBL plastic horn material, whatever that is.

2407H is stated to have a 1" throat in the literature.

It may be that greater precision IS warranted in tweeter applications....