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KLH speakers reference thread (original models/Henry Kloss era) 1957-1977

GD70 said:
A couple more pics.
Cab with woofer removed has some epoxy tub debris, where the gent started to chip away the epoxy, and then stopped. SN# 124334.
View attachment 2835524 View attachment 2835525
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I always found it fascinating how the designs of these speakers evolved. From everything being epoxied and inaccessible, then just the woofer and electronics to finally everything being removable. Still one of my favorite vintage speakers...

Edit: Please keep us up to date on the progress of these, can't wait to see how they turn out.
 
There's a step before the epoxied drivers. The Model One and Four, at least,
had cast aluminum frame woofers at first. A former KLH employee said the
casting machine/s wore out, and that's when Kloss developed the other cast
process (epoxy, though I'm not positive it's epoxy- probably some glue mix).

index.php
 
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GD70 said:
These are in the cue for restoration. I received these from the 2nd owner, came with the home he bought years ago, seller was original owner.
He was selling the house, and because of his age, couldn't complete the work, especially dealing with the crossovers. He supplied the caps, View attachment 2835439 View attachment 2835440 View attachment 2835441 surrounds already resealed.
Walnut cabs are in overall excellent condition. SN#s 122260-124334, 1968.
Here's a couple pics for reference. These have removable drivers, but the epoxy tub crossovers.
Looking forward to digging into these soon.
Cheers, Glenn
Click to expand...

I'm sure you'll do a good job with them Glenn.
 
KJ244 said:
Enjoy your work Glenn. Curious if you prefer removing the epoxy room temp or do you heat first? Cabinets look nice.
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Thank you!

I prefer room temperature. It's very brittle by now from age.
Best way to remove it is from the back. The plate needs to be very carefully removed for access. Then chip away with a flat blade screw driver and hammer. Doesn't take long.
 
GD70 said:
Once the bulk of the epoxy is removed, it will tale some time and delicacy removing-cleaning up from the switch and resistors so nothing gets damaged.
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Glenn, once you chip it out and complete the refurb, what do you use to reseal the hole? Is it just the insulation or do you cut wood to cover the hole to button things back up?
 
Here's what I did on a pair of Model Fours- fairly thick metal plates under
the original terminal plate, some duct seal, and screws at the four corners
of the box opening. Probably some overkill..

.finished_plate.jpg

mounted3.jpg


mounted4.jpg
 
marcthisdate said:
Glenn, once you chip it out and complete the refurb, what do you use to reseal the hole? Is it just the insulation or do you cut wood to cover the hole to button things back up?
Click to expand...
I cut a thin foam gasket, about 1/2 inch wide that fits around the cutout, but not visible once the plate is put back on. Plate remounted with small self tapping screws so it’s easy to get back inside if ever necessary. I had to drill out the holes in the plate slightly larger for the screws.
Link to my 1963s resto. Go to p.4. You’ll see the gasket I made.
https://audiokarma.org/forums/index...nal-1963-owner-pics-restoration.520806/page-4
 
I apologize for my tardiness in responding. I find AudioKarma difficult to navigate because the posts are not chronological. I have been searching for this thread for over a year and finally found it. If anyone can suggest how to easily return to this thread, I'd appreciate it.

Your photos confirm my memory that the 12 used a larger magnet than the 5 and 23. I makes sense because the 12 had about twice the enclosure volume of the 5/23, and using the same magnet the woofer would have been underdamped in that enclosure resulting in flabby bass. I always wondered about the woofer in the Model 7, which had twice the enclosure volume of the Model 6. Did it also use a larger magnet? I don't know.

RxDx's photos Model 5 tweeter array are the first time I've ever seen that product's innards. The two angled tweeters must be the GE tweeter I had heard about but never seen. That tweeter was also used in the first generation Model 4. Someone wrote that it was also used in early Model 6s, but that is not true. The Model 6 used the now famous and widely copied "phenolic ring" tweeter that Henry designed and that was made entirely at KLH. Around 1961 the Model 4 was redesigned to use two of the tweeters. That tweeter was also used in the Models 7, 17, and 20. The Model 5 and 12 used a variation with a thinner top plate that had more extended high frequency response. I always wanted to ask Henry how those two tweeters differed but alas, I never did.
 
BTW, if you have an ohm meter, I'd be curious what the DC resistance is of the Model 5 and Model 12 woofers. Likewise the person who had the two tweeters with the thin and thick top plates, I'd like to know the DCR of those 2 voice coils.
 
700K said:
I apologize for my tardiness in responding. I find AudioKarma difficult to navigate because the posts are not chronological. I have been searching for this thread for over a year and finally found it. If anyone can suggest how to easily return to this thread, I'd appreciate it.
Click to expand...
Click on the blue icon representing you, on the far left. That takes you to
your profile, including all your posts. From there you can find the ones
you put in this thread.

Or use your browser to set up a link to the thread. As far as I know, posts
in a thread are chronological, and threads themselves in the forum are also
chronological by most recent post. There are probably settings in the forum
software to change that; I just don't know, I've never needed to.

700K said:
Your photos confirm my memory that the 12 used a larger magnet than the 5 and 23. I makes sense because the 12 had about twice the enclosure volume of the 5/23, and using the same magnet the woofer would have been underdamped in that enclosure resulting in flabby bass. I always wondered about the woofer in the Model 7, which had twice the enclosure volume of the Model 6. Did it also use a larger magnet? I don't know.

RxDx's photos Model 5 tweeter array are the first time I've ever seen that product's innards. The two angled tweeters must be the GE tweeter I had heard about but never seen. That tweeter was also used in the first generation Model 4. Someone wrote that it was also used in early Model 6s, but that is not true. The Model 6 used the now famous and widely copied "phenolic ring" tweeter that Henry designed and that was made entirely at KLH. Around 1961 the Model 4 was redesigned to use two of the tweeters. That tweeter was also used in the Models 7, 17, and 20. The Model 5 and 12 used a variation with a thinner top plate that had more extended high frequency response. I always wanted to ask Henry how those two tweeters differed but alas, I never did.
Click to expand...
I wondered about the heritage of the phenolic tweeter, since KLH systems
are the earliest of which I'm aware that used them. You're the first I've seen
to state they're a KLH invention. Another correction to the list- sources of
the two Model Four tweeters.

Thank you again for your invaluable information and reflections.
 
Here's a bit or trivia. The KLH 12 was to have been a hybrid speaker system. It was going to have an acoustic suspension woofer and an electrostatic tweeter. Arthur Janszen had designed an array of approximately five 1"x 4" electrostatic panels in an arc to provide dispersion. On array was horizontal and the other vertical. The enclosure was about the same size as the final KLH 12. The problem was that the electrostatic tweeters were too inefficient to match the output of the woofer, so that version was abandoned and replaced with the all dynamic driver Model 12.

I also want to correct a post about the KLH 9 Electrostatic speakers. They were designed by Arthur Janszen, and everything was manufactured at KLH except for the Janszen tweeter which we purchased. The KLH 9's continue to be manufactured and serviced by Arthur's son, David Janszen, at Janszenaudio.com.
 
Anyone recognize this odd-ball KLH (Classic Series Model CL-4)? Everything appears to be factory built. Sound amazing.*I refoamed and added new velcro strips when I first obtained them some 5 or 6 years ago*
IMG_4855.JPGIMG_4854.JPGIMG_4853.JPGIMG_4856.JPG
 
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Better late than never. I'm a huge fan of Henry Kloss and his 2 way speaker designs. I own the model 17, 21, 24, 19, and my favorite, Model 23. There nothing they can't do, with the exception of heavy metal. Jazz, classic/ prog rock, blues and classical are silky smooth with these speakers. I don't listen to as much metal as I once did, so it's not a big deal but they just don't handle the high screeching guitar. A very warm speaker indeed and never fatiguing. Crossovers are simple to work on and capacitor replacement, speaker surround sealant are a must to get the best out of the vintage KLH
 
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