2408H

[pos]

Any information on that one?
How is it related to 2407H?

here is a system it is used in:
http://www.jblpro.com/products/porta...mrx/MRX512.pdf
http://www.jblproservice.com/pdf/MRX...es/MRX512M.pdf

HF Driver: 1 x JBL 2408H 37.5 mm (1.5 in) annular polymer diaphragm,
neodymium compression driver

id number is 361549-001X, diaphragm is D8R2408

[pos]

no info/opinion on this one?
Is this also a BMS driver?

[pos]

further investigations:

It looks like the 2408h has replaced the 2407H is some models in the vertex serie:

VT4887, 2407H "Ring Radiator" :
http://www.jblproservice.com/pdf/Ver...ies/VT4887.pdf

VT4887A, 2408H "compression driver"
http://www.jblproservice.com/pdf/Ver...es/VT4887A.pdf

So I gather that the 2408H is a compression driver whereas the 2407H is a ring radiotor. Though they are used the same way on the same horns, and achieve the same frequency extension.

EDIT:
from the transducer list:
2407H (339150-001X) TRANSDUCER $200.00
2408H (361549-001X) TRANSDUCER $118.00

[edgewound]

Here's my opinion on it...I say opinion because I haven't asked anyone at the factory, and lets just say the factory is less than forthcoming in regards to using another mfg's driver. After all...this is JBL...a driver manufacturer.

The 2407 and 2408 are both ring radiators of the compression driver variety.

The 2408 has more aluminum to better dissipate heat, is built differently and looks to have a different exit path via a larger aluminum phase plug. The diaphragms look very similar, if not identical.

I can imagine that JBL took a very good driver in the BMS style 2407 and added their own touches to make the 2408 a bit beefier....not mention the BMS branded diaphragm won't physically interchange with the 2408, although the screw pattern is different in the BMS and JBL 2407.

[pos]

So the 2408 would be a more integrated JBL product with less BMS technologie, whereas the 2407 was a direct adaptation of a BMS product? That would explain the price difference, with the 2408 being 40% less expensive: borrowing pieces and technologies is more expensive than integrating them. Or is it just that the 2408 is the current product whereas the 2407 would already be phased out, and thus more expensive?

edgewound, if you had the chance to listen to these 2406/2407/2408 in a HF horn (>6khz), how do you think they compare to the old 2402/2403/2404/2405 ring radiators?
Do you thing the beefier design of this 2408 would have any advantage over a 2407 in a hifi setup?

[edgewound]

edgewound, if you had the chance to listen to these 2406/2407/2408 in a HF horn (>6khz), how do you think they compare to the old 2402/2403/2404/2405 ring radiators?
Do you thing the beefier design of this 2408 would have any advantage over a 2407 in a hifi setup?

I don't think their would be a huge advantage in a hi-fi setup. These mylar diaphragms have a much less fatiguing nature to them with still having incredible hi end extension.....much more natural sounding.

Not to say the older aluminum ring radiators are bad....'cept the 2402....haha...can be painful. My favorite of those is the 2404H(-1 )baby butt cheeks. I love the 100x100 degree dispersion.

[Old Pink]

So the 2408 would be a more integrated JBL product with less BMS technologie, whereas the 2407 was a direct adaptation of a BMS product? That would explain the price difference, with the 2408 being 40% less expensive: borrowing pieces and technologies is more expensive than integrating them. Or is it just that the 2408 is the current product whereas the 2407 would already be phased out, and thus more expensive?

edgewound, if you had the chance to listen to these 2406/2407/2408 in a HF horn (>6khz), how do you think they compare to the old 2402/2403/2404/2405 ring radiators?
Do you thing the beefier design of this 2408 would have any advantage over a 2407 in a hifi setup?

Here a link to HD pictures of my disassembled BMS drivers

http://www.flickr.com/gp/80559753@N00/K9T2XD

[pos]

I save here an drawing from Old Pink's flickr album posted above.
Very informative, thank you Old Pink!