250 ZI !!!!

[gerard]

Hello

For thsoe who would be interested first pics of my 250 Project .

Hope attachment works

Gerard

[Don Mascali]

Thanks for the pics. Please keep us posted.

I get vicarious thrills from watching projects as they move along. I always seem to learn something from you guys too.

[JBLnsince1959]

really cool....let us see more as you go along.

[Titanium Dome]

Looking sharp! Gerard are you in front of or behind the camera?

[gerard]

I am with the blue shirt , left side !

Gerard

[Guido]

Do not forget massive bracing!

My 250ti are braced heavy as hell.

[gerard]

Guido


bracing only at woofer height or also upper ?

Gerard

[Guido]

The whole cab.

All edges and 3 transverse in height at each side. Use every hardwood app. 4 x 2 cm will do.

Oh and lower midrange has a own doghouse. But I think you know that.

[mike]

I'm impressed. I think building a pair of 250Ti's would be quite an undertaking.
250Ti's are veneered on the inside as well like some of the older JBL's and some high end european speakers. I don't know why they did this.

Good luck,
Mike

[gerard]

Hello

very interesting the venneer inside .

Can someone explain ? I still have the time to do it if there is any reason !

Gerard

[DavidF]

Hello

very interesting the venneer inside .

Can someone explain ? I still have the time to do it if there is any reason !

Gerard

I know that double-sided veneering is a long used furniture making technique that reduces problems with warping of panels veneered only on one side. The natural expansion and contraction of the material is working against the glued veneer side with one side treated. Veneer and glue on both sides tends to balance out things. Not so sure how the use of MDF and particle board differs from plywood in terms of expansion and contraction. Internal cross-braces would seemingly reduce the tendency of large panels to shift and warp.


DavidF

[Guido]

Mine are piano black and therefore not veenered. Inside is only MDF.

[gerard]

Guido ,

How would you compare the sound of your 250 ti to your 4343 ?

gerard.

[bbrown]

The panels were probably bought by JBL already veneered (both sides). Then cut and assembled. It would be less expensive and easier to do that way. And look great when you removed a driver to peek inside.

Bruce