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r1systems
01-12-2013, 03:23 PM
I am about to start a build on a pair of 616s. My only question is, what is the radius for the horn flair?

Earl K
01-13-2013, 07:25 AM
I'd suggest you simply adapt the ( flare ) measurements of the 815 and fit them into the 816 .

http://www.lansingheritage.org/images/altec/plans/1970's-lf-plans/thumbs/enclosures08_small.jpg (http://www.lansingheritage.org/images/altec/plans/1970's-lf-plans/enclosures08.jpg)


The horn flares really aren't simple arcs ( or a specific radius rotated around a fixed point ) .

They are more of an exponential curve ( of some type ) .

:)

r1systems
01-14-2013, 05:04 AM
Ok thank you for the incite and help.

Lee in Montreal
01-14-2013, 02:00 PM
The horn flares really aren't simple arcs ( or a specific radius rotated around a fixed point ) .

They are more of an exponential curve ( of some type ) .

:)

Very often, they are marked as simple radius.
Shown below is the plan for a JBL 4560

http://kalkan0.free.fr/JBL 4560 PLAN.jpg

Earl K
01-14-2013, 02:20 PM
Interesting Lee ( about that radius ), Thanks ! .

Are those full size 4560's ( they look smaller than I remember ) .

I had 4560's back in the late 70's & I thought that they were deeper than that 22.5" spec. .

Maybe Mike(Bake) can enlighten us ( I think he has some originals ) .

:)

EDIT : answered my own question ( the 4560's in the 1975 catalogue are a little bit larger in all dimensions / even after 1.5" to create outside dimensions ) .

Earl K
01-15-2013, 03:04 AM
Well , after thoroughly looking through the 1970's Altec enclosures guide, I need to eat humble pie once again . :D

Apparently, all the LF cabinets that have "shallow" horns ( meaning they are only 14" deep or less ), use a simple radius to define their horn profiles ( just like the "4560" shown above ) .

See the 817 ( or A7 ) for the info on the radius used ( 30 31/32" or 31" ) ;

http://www.lansingheritage.org/images/altec/plans/1970's-lf-plans/thumbs/enclosures10_small.jpg (http://www.lansingheritage.org/images/altec/plans/1970's-lf-plans/enclosures10.jpg)http://www.lansingheritage.org/images/altec/plans/1960's-lf-design/thumbs/page14_small.jpg (http://www.lansingheritage.org/images/altec/plans/1960's-lf-design/page14.jpg)

:p