I have seen pictures but no plans for wood replacement JBL 077/2405 slotted lens bodies or the wedge phase plugs.
I have working 2405H drive units with largish horns that were adapted for arena use. So, I'm on the hunt for replacements that will likely come from dead drive units. But I'm also hopeful that I can fabricate my own out of wood for my home system.
Because I have seen pictures as I have been searching for plans I know it has been done. I would be happy to post a build thread or collaborate with someone who would enjoy a pair of slot lenses in exchange for workable schematics.
Thanking all in advance,
Bruce
I have working 2405H drive units with largish horns that were adapted for arena use. So, I'm on the hunt for replacements that will likely come from dead drive units. But I'm also hopeful that I can fabricate my own out of wood for my home system.
Because I have seen pictures as I have been searching for plans I know it has been done. I would be happy to post a build thread or collaborate with someone who would enjoy a pair of slot lenses in exchange for workable schematics.
Thanking all in advance,
Bruce
Bruce,
I have not seen the plans you are looking for, but it would be far easier to duplicate the parts out of wood if you had the originals on hand to compare exact dimensions, the throats of those "ring radiator" designs are tiny. Small variations from original dimensions can make large sonic variations.
The "baby butt cheek", "slot", "bullet" are polar opposites in terms of dispersion (polar response) and horn design, they each sound (and measure) completely different. IIRC the "slot" uses a different diaphragm than the other two, though either diaphragm can be installed in any of the motor structures, which changed from Alnico to slab magnets decades ago. All three horn types have been used in (right & wrong) applications in everything from home stereos to "studio monitors" to arena sound systems.
A pair of "bullets" with "slot" diaphragms has been used as an ultrasonic send and receive unit for traffic control, if you locate "army green" units, they were likely "liberated" from roadside installations in rural locations in the USA's southern states. The "bullet" with a "slot" diaphragm on-axis response rises steadily from 3KHz to around 21kHz.
At 21kHz the beam-width is only a few degrees, a car or even a pedestrian passing through the narrow beam is enough to trigger a relay that changed the light from red to green for the traffic when no other traffic was detected.
Any of the three horn types would look nice made of wood, but depending on the type of wood used, they won't sound any better, and if a soft wood is used, will sound worse than the original units.
You have a lot of work "cut out" for you for some tiny parts that sound better when they are behind a grill cloth that won't be a constant reminder of an aesthetic choice you may later change your mind about 😉 .
Cheers,
Art
