JMLC horn for JBL 2452sl

[lbstyling]

Hi all,

Im looking for a conical stand alone horn for a JBL 2452, but I have some questions that im looking to answer before I go any further.

Im interested in the JMLC 350hz and ferguson horns that jzagaja sells, but I cannot find any graphs for FR or other data of the driver I have (or similar 24xx drivers) on this kind of horn.
The exit angle of the driver is 10 degrees (so im told), what would the throat angle be on the jmlc horn? Does it matter?
what is the T factor of the jmlc 350?
The 2452 is a 1.5" driver, Jzagaja only lists 1.4" not 1.5" as available mountings- Does he do a 1.5"?

http://www.autotech.pl/pdf/audio_en.pdf

Any help apperciated!
Thanks

[lbstyling]

bump!

[jzagaja]

JMLC-350 can be cut to any throat. With 1.5" resulting throat angle is 7.8deg. Only modern "waveguide" drivers have significantly larger throat angle.

[pos]

The 2452SL is throatless ("optimize aperture" design), so a 0° angle would be ideal, but I guess any small exit angle will do.
http://www.jblpro.com/catalog/suppor...=298&doctype=3

[lbstyling]

thanks guys,
Obviously 0 degrees is ideal, but I cant see what other option I have unless I make it myself.
Is there a way around this? has anyone tried building up the first few mm of the horn with putty to graduate the transition between the driver and horn angles?

[whgeiger]

Originally Posted by lbstyling

thanks guys,
Obviously 0 degrees is ideal, but I cant see what other option I have unless I make it myself.
Is there a way around this? has anyone tried building up the first few mm of the horn with putty to graduate the transition between the driver and horn angles?

Buy the horn version with an Rt = 1" and design/build an adapter block to match driver to horn.

Use a cosh flare to match the tangent angle [Am] of the horn at the throat radius Rm = 1"

Formula to use to determin the profile:

Rm = Rt*cosh(m*Lm)= 1.0"

Tan(Am)= m*Rt*sinh(m*Lm)

Lm - Length of adapter

Rt - Radius (ordinal) where driver an adapter join
= .75"

m - Flare coefficient of the adapter
(Adapter Fc <= Horn Fc)

Regards,

WHG

[lbstyling]

Hi whgeiger,

Im having difficulty understanding your post. The driver is 1.5", so are you suggesting getting a 2" version of the horn and making an adapter piece that goes between the horn and driver to make a tighter angle transition?

jzagaja, what is the final throat angle on the 2" version?

[whgeiger]

Originally Posted by lbstyling

Hi whgeiger,

Im having difficulty understanding your post. The driver is 1.5", so are you suggesting getting a 2" version of the horn and making an adapter piece that goes between the horn and driver to make a tighter angle transition?

jzagaja, what is the final throat angle on the 2" version?

From Driver:
Rt = 0.75", At = 0.00 deg.

To Horn:
Rm = 1.00", Am = (from jzagaja)

You adjust m & Lm to get a matching Rm & Am for the adapter.

If you want a design, once [Am] is known, I will send you a drawing.

Regards,

WHG

[jzagaja]

Originally Posted by lbstyling

jzagaja, what is the final throat angle on the 2" version?

Sorry for mistake - throat angle is constant 7 degrees up to 2".

[lbstyling]

Originally Posted by whgeiger

From Driver:

If you want a design, once [Am] is known, I will send you a drawing.

Regards,

WHG

That would be amazing! as you obviously know WAY more than I do about horn profiles