JBL 2370a horn adapter

[Mitchco]

Hello, I am Mitch from the West Coast in Canada and new on this forum.

I have a DIY triamped/time-aligned hifi system that uses a 2380a 90x40/Selenium D405 combo to drive the mids from 500 Hz to 5 kHz. For 5 kHz on up, Selenium HM 1125 60x60 exponential horn/BMS 4540 combo.

The 2380a sounds great to my ears and would love to match up the HF polar response with a 90x40 biradial horn as well.

The 2370a would be the match, but the BMS 4540 is a 1" screw-on. I don't know if there is an adapter that would work and not compromise sound quality?

If that won't work, any other HF horn recommendations that would compliment or match the 2380's polar response?

To complicate a bit further, any horn replacement likely won't fit the cab so will have to sit on top with it's own baffle. The top of the cab is 39" off the floor and adding a horn on top will put the tweeter axis 6" above ear eight with respect to the listening position about 10' away. Issues?

Thanks in advance,

Mitch

[macaroonie]

Here's an adaptor that should do the trick. It comes on 2426 drivers. Some of the gang will have these lying in a drawer somewhere. I've a couple you could have buckshee but I'm a long way off. If no one else pitches up get in touch.
The part you need unscrews from the 1 3/8" thread that is on the driver. Thats it with the mounting lugs etc


60912

[allen mueller]

Parts Express has what you need $2.79

http://www.parts-express.com/selenium-adf25-25-horn-adapter--264-322

Al

[ivica]

Hello, I am Mitch from the West Coast in Canada and new on this forum.

I have a DIY triamped/time-aligned hifi system that uses a 2380a 90x40/Selenium D405 combo to drive the mids from 500 Hz to 5 kHz. For 5 kHz on up, Selenium HM 1125 60x60 exponential horn/BMS 4540 combo.
The 2380a sounds great to my ears and would love to match up the HF polar response with a 90x40 biradial horn as well.
The 2370a would be the match, but the BMS 4540 is a 1" screw-on. I don't know if there is an adapter that would work and not compromise sound quality?

If that won't work, any other HF horn recommendations that would compliment or match the 2380's polar response?
.............
Mitch

Hi Mitchco,

For the application of BMS 4540 I can suggest to try:

-SELENIUM HORN HM-17-25 [dispersion: 80x60]
-"18-SOUND XT-1086" [dispersion: 60x40]

generally it would be very difficult to reach 90 degs dispersion for high-frequencies without a kid of a diffraction slot.

Regards
ivica

[Mitchco]

Hi macaroonie and Al, thanks, perfect. ivica, thanks I have looked at that Selenium biradial before and still considering it. Probably the easiest solution for me as it is almost a drop in replacement to the HM11-25.

Since I first posted this, I have looked around the site and found JBL's PT-F95HF which appears to be the evolution of the 2370a? Comments? Then I saw references to Oblate Spheroidal waveguides. Now my head hurts :-) Probably best to go with the HM-17-25.

Thanks again for your assistance.
Mitch