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A piece of Kloss History!


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As many New England speaker fans know, before Henry Kloss met Ed Vilchur and convinced him to go into manufacturing acoustic suspension speakers (since no one would buy the idea  ), Henry built cabinets for Baruch-Lang loudspeakers in his Cambridge loft to support himself while he went to school.

According to a 1952 Popular Science article: http://books.google.com/books?id=SiEDAAAAM...lt#PRA3-PA71,M1

"Just by drilling holes in the cabinet, two sound engineers have made an acoustic unit using cheap, small speakers sound as good as a costly big job. The holes do the trick by "tuning" the cabinet and baffle to compensate for inadequacies in the four 5" speakers. Calculating the hole size was so complicated that an electronic computer was used to figure it out, report the inventors, Dr. Jordan J. Baruch and Henry C. Lang of Massachusetts Institute of Technology.
Dr. Baruch and Lang say their unit, with two watts of amplifier output, reproduces the tonal range and volume of a full symphony orchestra. It is said to be "flat" (accurately imitating the original loudness) over a frequency range of 40 to 11,000 cycles, which covers most tones audible to the human ear.
The Baruch-Lang speaker, small enough to fit on an end table, promises to bring out the full quality which is inherent in FM radio and TV sound, but which now is often distorted by inadequate speakers. It will be marketed by Ultrasonic Corp., Cambridge, Mass., for less than $30."
These speakers were sold mail-order as well as locally in Cambridge. The basic speaker cost $25 "in a handsome, mahogany veneer cabinet--in your choice of four modern decorator finishes to blend with every decor." And for $30 you could get the "Deluxe Model" "with a handsome frame and grill for added beauty. Available in the same luxury finishes...Blonde Modern, Rich Mahogany, Chinese Black and Natural Unfinished." see the attached pdf file--it's an ad from Audio mag

I recently bought one, in nice condition, although the backs and sides are flat black painted plywood, so I don't know if this was modified or came as a utility version. I hooked it up to a 1960 Henry Kloss KLH Model Eight radio and it sounds surprisingly good. CSP member and KLH historian Andrew Hayden has written briefly about this speaker, noting it would be interesting to replace the 4 drivers with later KLH full-range speakers that were used in the later Model Eights, but I think this speaker is pretty nice "as is." [Andy--if you follow this thread please comment].

An interesting piece of audio history!







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Hi Kent, Thanks for the link and photos. I was going to replace the drivers on my Baruch-Lang speaker since the wiring is fouled up on mine, but have not done this yet.....maybe I should leave the drivers and just re-wire them. It looks like yours have been re-wired ? Mine has uncoated wire (bare). Originally I thought the later KLH 4 inch drivers would be a good way to restore the Baruch-Lang, but I think leaving the originals may be the smartest thing to do.

Also, my speaker has the plywood back/sides as yours does, but mine does not have the 4/16 ohm terminal like yours...my wires just exit the back of the cabinet. These are neat speakers from the earliest days of Henry Kloss speaker building.

An interesting aside - My father inlaw was at MIT in the early 1950's when Kloss was there, but did not know him. He tells me that a few people were building speaker cabinets, putting small factory drivers in them just to have a loudspeaker which had good sound. In fact, he still has a cabinet he bought from some guy - plywood, hole for a 6 inch driver, has an internal baffle and is vented with small holes just like the Baruch-Lang is :rolleyes: maybe it's from the loft of Henry KLoss ? Next time we visit him, I think I'll rescue this cabinet from his basement and compare construction details ! As I've mentioned on this forum before, Kloss was a skilled woodworker and made his own furniture for his loft while at MIT. What a great way to make a little money - build speakers ! Little did he know that within five years he'd be on his way towards audio fame....AR, KLH, Avdent and so on..

Early New England loudspeaker history at it's best -


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Update to this old thread:

I acquired a second Baruch Lang a few years ago, in rougher shape and somewhat different in appearance. Recently I put it on epay and was contacted by a fellow CSP member (who wants to remain anonymous but I hope he'll chime in) who provided some insights.

This one had damaged grille cloth, so I replaced it with Irish Linen. Easy peasy--just 4 wood screws and the baffle comes off, but I wish I'd sealed the baffle with shellac because when I spritzed the linen to make it taut some of the mahogany stain bled through. Live n learn 🤨. The drivers are definitely Carbanneau (EIA #719) and it was my understanding they are the same drivers used as mid/high in the AR-2a.

Turns out this one was not built by Henry Kloss. Note the Ultrasonic name on the upper left corner). According to the fellow CSPer, these were "an open-source design, and students made them in the MIT workshop. Kloss sold his own version, as did Ultrasonic. The frequency response is, of course, pure fantasy, and they sound, well, like radio/TV speakers from the 1950s. Craps out around 6 to 8k Hz. . . .  . The drivers, BTW, were heavily modified to work as tweeters in the AR-2 so it's not exactly an apples-to-apples comparison". He also notes the bottom end is probably around 150Hz. For modders, he offered some suggestions:

  • stuffing the cabinet with polyester fill or fiberglass to slow the backwave, as with any ported cabinet
  • lining the cabinet with cotton batting to reduce reflections
  • replacing the tissue paper with filter scrim to form an aperiodic port, improving the low-frequency response
  • implementing RC, RL, or RLC impedance compensation, which certainly was possible in the 1950s had anyone thought about it, as RDH is chock full of the requisite information)
  • adding an external tweeter and subwoofer, with crossovers to prevent overlap and comb artifacts
  • upgrading the drivers to ones with whizzer cones and a more compliant non-paper surround which would lower Fs

Anyway, still an interesting bit of audio history.







2nd BL 6.jpg

Baruch Lang Ultrasonic_17.jpg

Baruch Lang Ultrasonic_1.jpg

Baruch Lang Ultrasonic_2.jpg

Baruch Lang Ultrasonic_12.jpg

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