FYI, from the joelist: free Jensen Imperial

[GM]

Could make for a nice Altec loaded sub or mono 604 system........

GM
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Hey Joes,

I'm downsizing and need to get rid of this large corner horn speaker
Cabinet. It was made for the Jensen Imperial system of drivers, LL15
woof, RP201 mid horn, and maybe an EV T35 tweeter, judging from the
tweeter slot.

Pictures can be seen here:

Jensen Imperial Corner Cab - a set on Flickr

The Cabinet measures 44"H x 43W" at the widest part, horn sides are
25", it is 26" deep. The bass horn is rear loaded, double folded, and
comes out both side grill panels, as well as the top where the mid/
high drivers go. It is for a 15" woofer.

I hate to throw this away as it is very well built, homebrew, of 3/4"
high grade plywood, from back in the '50s when men were men and built
their own audio gear, just like us. It's just what YOU need for that
corner horn speaker in your garage. The XYL will never know it's
there, you can hook it up to a 2 watt triode amp and listen in bliss
while you work the hours away on your favorite car project, or
whatever. With an altec woof, a little sawing so you can fit an an
811B horn, and you could have a terrific 2 way. The horn is mounted
on a 3" base. If you are into mono as I am, with a big collection of
78's and mono lps, this would be just the speaker to get the most out
of your collection. Mono Mia!

I will keep this until the week of April 27, then I have to get rid
of it, so sez m'lady, and I agree. SOOOOO, if you want it, you have
to come and get it. I am in Massachusetts, halfway between Boston and
Providence, right off of Route 495. I will not ship the horn. It is
FREE for the coming and taking away. After April 29 the bad boyz are
gonna come and take it away in the trash truck if it's still here.

Best to all you Joes,
Uncle Henry

[Kercher]

Wow, I thought the joelist died out years ago. Where is the new board?
Dan

[speakerdave]

That's not an Imperial. It's another, simpler corner horn that Jensen published in the early/mid fifties for DIY construction and was called the Superhorn or something like that; I can't remember right now exactly what they called it. It requires the corner of the room to really work. It was one of several variants of the same basic idea of a fairly simple single fold path using the walls coming out of the room corner for bass extension.

[speakerdave]

Well, I guess it's not that either. I found my clipping of the Bass Ultraflex enclosure. Both 12" and 15" versions of it were described by Daniel Plach and Philip Williams in the December 1954 issue of Radio and Television News. The Ultraflex is a little different and looks to me like a simpler and better design. In fact the more I look at this "Imperial" the less sense it makes to me with that faux back chamber/reflector behind the woofer. It looks like both designs slot load the back wave after a fashion and then port that into an expanding "horn." Both versions of the Imperial, the built-in and the free-standing, have an expanding horn path (hyperbolic, I think) that unloads either at the top or the bottom of the cabinet.

[speakerdave]

Drawings and build articles for both versions of the Imperial, the Bass Ultraflex and the Onken can be found here:

Jensen Imperial

[GM]

Cool! Thanks!

Anyway, I copy/pasted the email without even reading it, but after looking at the pics it appears to be a well thought out Imperial adaptation of the standard corner horn 'accordian' folding scheme, though of course with no dimensional details I can only speculate as to how closely it might perform in a corner Vs a bone fide Imperial corner horn. Still, its gross bulk implies ~comparable low end performance, so if I lived nearby I would have already picked it up if nobody beat me to it rather than posting it.

GM

[GM]

Wow, I thought the joelist died out years ago. Where is the new board?
Dan

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GM