These were tough to build. The drivers are a matched pair of 12" Cletron C12NR full range Alnico speakers made by the Cleveland Electronics Company in the late 1950's. These cathedral series drivers with low compliance surrounds, Alnico V magnet structures, large 8 ohm 2" voice coils, and feature stiff ribbed cones, with a very stiff whizzer cone which doubles as a short horn for the gold anodized center voice coil cover/high frequency dome radiator.
The Cabs are built in 3/4" Cherry plywood with hardwood edging. They combine elements of a sealed box with a transmission line / horn component. I think the design is similar to some old Electro-Voice cab designs. Here are some bad pictures of the finished product with a danish oil finish:
The driver sits in a 21.5" wide, by 28" high by 10" deep box that has a 12" wide by 3" high slot cut out of the top back. This feeds a tapered TL that runs down the back of the speaker and exits via a 2.25 inch high flared horn (from 12" at the back to 19" at the front that is below the main box. The box and TL is lined with carpeting and there is a Deflex Pad behind the driver. It was challenging getting all the joints flush and clamping up these irregularly shaped objects. Here are some pictures of the construction process:
I never could have built these without the help of my friend, Lex Holmes, the man with 1,000,000 clamps and some pretty big mallets! Thanks Lex!!
Now, the sound. Man, these sound so $%^$ great!! There is some serious authoritative Bass, even when driven by my flea powered decware amp, the midrange is incredible, the imaging and detail and musicality of these guys in my system is wonderful. There is plenty of high end extension too, especially since I tweaked my amp by changing the coupling caps to Hovlands. The overall coherence and fun factors are the highest I've experienced.
I feel like I got really really
lucky. I bought the drivers on a whim, thinking to try them on open baffles,
but the seller enclosed plans for the cabinets. I couldn't build them on
my own, but I got Lex interested, and the rest is history!
My name is Kevin and I am hooked on low excursion, paper cone, single
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