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Cizek KA-1


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Just bought some Koa wood KA-1 speakers that I'm eager to restore but one tweeter has a ripped dome. The tweet is apparently a Peerless KO10DT - 810665. These were once common but now not available. They came in 4 ohm and 8 ohm versions so when I get the speakers I'll have to check to see which is used here.

Midwest Speaker sells a new replacement but it's a copy--not a Peerless. Any thoughts or advice?


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Update: The speakers have arrived and the DCR of the tweet is about 7.8 so it must be the 8 ohm version.

The speakers have other issues: The stuffing has been removed and the inductors were loose. One had a broken lead.

So a question for you KA-1 owners: Do you know how much stuffing these get (and is it poly or fiberglass)? And does anyone have a crossover schematic?

Thanks for any info.


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Working on the KA-1s. They were in rough shape, with a damaged tweeter, missing stuffing, some weird resistors added to the woofer circuit, no grilles or logos, and very grimy and dull looking. But they ARE KA-1s, and low serial numbers to boot.Our resident Cizek expert, Paolo Lippe sent the schematic but it did not have values on it so John O'Hanlon figured it out long-distance based on what I could observe (capacitors and resistors were stamped) and what we inferred from my measurements of the inductors. It's a very sophisticated (some might say overly-complex) crossover design that I'll leave to John to explain if he's so inclined.So here's the xo.
Also attached: A shot of the cabinet with water ring.
Fortunately these are solid wood so they could be sanded aggressively. Started with 60 grit in the orbital sander and worked up to 600.
The crossover was kind of a mess. Two inductors were knocked loose, one inductor had overheated, scorched and melted the bobbin. Fortunately it's not "too" far out of spec. Caps are those leakage-prone PVC jobs often found in KLH speakers. edit: original and rebuilt xo shown in post #4
More photos to follow.






Edited by JKent
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Rebuilt one xo. Shown here are old and new. I "thought" I had to relocate the big inductor because some resistors were in the way. Turned out the resistors didn't belong there so I could have left the coil where it was. No big deal--it had been knocked loose and had to be reattached.

I used a bunch of 10uF Madisound surplus caps, plus a Carli 4.7uF and a 10uF that was leftover from another project.

Replaced the 2.5 ohm 5 watt resistor with two 5 ohm 5 watts in parallel because I don't trust 5w resistors. Result is 2.5 ohm 10w.


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  • 3 weeks later...

Dear JKent:

You have found one of the few speakers that I actively seek, but don't really expect to find.

A gem to admire both visually and sonically, as I have listened to a pair on youtube (I know the sound would not be accurately represented via youtube, but . . .).

I cant wait to see the end result of your refinishing the cabinets.

Perhaps you could tell us how you found them, etc.

Glad to see that a piece of audio history is being rebuilt.

BTW, just look for a vintage pair of Polk Monitor series (5, 7, 10 etc.) and you should be able to get the Peerless that originally came with the Cizeks.

I happen to own a mint Model One pair, and they do sound superb, and have amazing cabinets.


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As Weird Al Yankovic sang: "I found them on ebay."
I too had been looking. The ones I ended up buying had several issues (as described above) but I knew they were special. I'm glad the wood looked so dull in the photos. The speakers did not look like much at all.
Thanks for the tip re Polk tweeters. I actually did discover that in my research. Also found that early Polks used the Peerless tweets but later ones used Polk-branded tweets that may not be as "good" as the Peerless. Also, both versions of the the Polk tweeters had small holes poked in the silk domes. Anyway, I did find a Peerless on eBay. Next I need grilles (probably can build my own) and logo badges. Until then, the Cizeks look pretty nice "naked."
Have been away 2 weeks but hope to get back to the restoration this week. I just ordered some new binding posts. Will guess at the amount of stuffing to use. I figure the Cizek has "about" 1/2 the internal volume as an AR4x. The 4x had 11 oz of fg so I'll try 5 oz and see how it sounds.
I'd like to know more about the Model 1. Apparently the 1 and the KA-1 were completely different animals.
Thanks for the interest.

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Thanks Vern.
One is finished. The ugly ring on the bottom is 95% gone and the wood cleaned up nicely. I sanded with an orbital sander, starting with #80 grit and working up to #600. After considering lots of advice on refinishing the koa wood I went with my old stand-by: Minwax Antique Oil. It's similar to Tung oil insofar as it is wiped on but has some varnish or something in it to make it glossy.
Applied MANY coats (did not count), sometimes rubbing with steel wool in between.
The heavy "Acuthane" front panel was cleaned, polished a little with some automotive rubbing compound, then a coat of Armor-All was applied.
The binding posts had been replaced once. I installed new gold-plated ones from Madisound.
Had to guess at the stuffing. First I weighed a small package of Johns Manville white fiberglass with a fish scale and found it to be about 10 oz. I cut it in half, figuring 5 oz per speaker. The 5 oz piece was cut into smaller pieces to allow for easier installation.
Initial listening tests: Sounded very good but a bit over-damped so I took out some of the fg to bring it down to about 4 oz (which is what John O'Hanlon had suggested in the first place). To my ears, that seems about right.

edit: Just opened a 2nd pair of KA-1s and found them tightly stuffed with 9 oz of fiberglass! Will have to go back and play with the stuffing some more!
Second listening test: These sound GREAT! I did a comparison with A Bozak MB-80, which is a similar-size high quality mini monitor (see this thread: http://www.classicsp...?showtopic=3870). The Cizek sounds better. Tighter bass, great if somewhat forward mids, sparkling highs. I heard things on a Dire Straits album I'd never heard before!
Now I just have to finish the other one and figure out how to fashion a new grille. These are going in the living room!
Vern, I agree regarding the dovetail joints. Love those and the thick, solid wood. I have a pair of Cambridge Soundworks Speakers as surrounds that are solid oak with finger-jointed (like square dovetails). Am also using a single Cizek HTA as a single rear channel--no dovetails, but solid oak.






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  • 2 weeks later...

Another bump in the road :angry:

Put the second speaker back together and discovered it had a bad woofer! It read "open" on my ohmmeter. I was so focused on the torn tweeter dome and other issues when I bought these apparently I never checked the woofers! Dumb. Too late to go back to the seller now.

This may be a blessing in disguise. I sent both woofers to Bill LeGall (for anyone who doesn't already know, he's a speaker wizard and a really great guy). He'll work his magic on both woofers and return them better than new.

Can't wait!


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  • 3 weeks later...

Thanks for more kind words Vern.

The woofers have been returned. Bill LeGall (Millersound) did do a beautiful job on both, at a very reasonable cost. He made some improvements: Bill said he set the coil-to-pole-piece height differently than the factory did. Also, the spider is slightly more compliant and the cone material is the best sounding [he] knows of, for this speaker (it has the perfect balance between stiffness and retaining the non-aggressive sound of paper). Normally I take a dim view of "improvements" to classics but if Bill did it you know it was done right!

First impression of the restored speakers: Wow!

I do want to play with the amount of stuffing, both by ear and also with the Dayton DATS program. Here are some new photos, with the newly reconed woofers. I think the cabinets look great, even though I had to fill two knot holes with brown epoxy (shown in photos). Love the koa wood! The last 2 photos are "before" shots. Big difference!

You can see there is a felt ring (from Madisound) around one tweeter. Just experimenting to see whether it improves the sound but I think it does. edit: I removed the felt diffusers and also sliced the external woofer gasket flush with the basket frame so the new foam speaker grilles would fit better.

My reference speakers are the AR-3a's (much bigger) and Bozak MB-80s (just slightly smaller). The Cizeks sound more like the ARs! Brighter, even with the damping rings, but "full". By comparison the Bozaks are drier. It's interesting to switch among the three. All sound good but each has its own sound. It should be interesting to put the AR-4x's in the mix.

I've ordered new foam grilles in brown with beveled edges and a relief on the back to clear the drivers from this site http://foamspeakergrilles.com/ . They asked me to send them a speaker to fit the foam properly (and offered a nice discount if I did) but I hate to ship these--they're heavy and irreplaceable. Plan to put them in the living room to replace the AR-4x's flanking the TV, so they should have nice grilles just for appearance.









Edited by JKent
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  • 1 month later...
  • 2 weeks later...

Thanks Jesse

Final update:

I got the foam grilles from http://www.foamspeakergrilles.com They came with handy Velcro discs that stick to the front baffle. I used 3 on each long side and 1 about centered. I think they came out very well. The Velcro holds the grilles out a bit. I did not want to hide any wood so the grilles are exactly the size of the opening. If I were to do it again I might make them about 1/8" larger in both dimensions so I wouldn't have to be quite so careful putting them in place. foamspeakergrilles would have taken a speaker and made all the measurements but I did not want to send a speaker out with the perils of 2-way shipping.

edit: My second set of KA-1's came with original grilles. You can see them here: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=7858

This time I DID send a speaker, along with these new grilles and the originals, to foamspeakergrilles and he made 2 new sets but unfortunately was unable to re-create the original design. He did make the new grilles a bit larger though and they look good.

Now I just need the logos. If anyone has one that I could borrow, I'll send it to my engraver and have copies made. Anyone? I need the ones that look like this:http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=7728

edit: I did get some repro badges made. If anyone needs some let me know.

I installed these in the living room as fronts in a surround system, replacing my venerable AR-4x's. Did not do a side-by side comparison but I think the Cizeks sound better.


For those interested in HT: The setup is

  • Main front speakers: Cizek KA-1
  • Front wide speakers: Minimus 7 with Zilch xo mod
  • Front high speakers: Home-brew about the size of the Minimus 7
  • Center: rbh MC 414C (acoustic suspension, MTM configuration)
  • Sub: VMPS Original sub with Apex Sr. plate amp
  • L&R surrounds: Cambridge Soundworks "Ambiance by Henry Kloss" (a discontinued AS mini monitor with solid oak cabinet)
  • Rear: Cizek HTA Model AR-11

edit: info in red is updated to show current system as of 2019




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  • 2 weeks later...
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  • 1 year later...

While these KA-1s will not reproduce bass with the power of a subwoofer, their mids and highs sound great

Cizek made a matching subwoofer (the KA-18). I have never seen one "in the flesh" but found a photo on google http://www.audiocostruzioni.com/r_s/diffusori/diffusori-2/cizek-satelliti-sub/cizek.htm

Fantastic! Looks like these are in Italy. Maybe Paolo has seen and heard them.

Speaking of the KA-1. I saw some on ebay but was too late to buy. Good thing! These "Cizek KA-1" speakers were KA-1 cabinets with who-knows-what inside. And they're ported! Sacrilege :(

Here are 2 photos: My (real) KA-1s and the impostors.




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  • 4 months later...

Another set of impostors from ebay. This pair had the original Cizek woofers discarded and replaced with a pair of aluminum (!) cone woofs. And the guy wants huge bucks for these bastardized speakers. I doubt any would-be restorer will find suitable replacements. The original woofers had paper cones and huge magnets as shown in the 2nd photo (this woofer was reconed by Bill LeGall).




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  • 4 months later...


I'm, Sergio from Italy owner since 1982 of a pair of Model 3 and it's a pleasure to have a chance to meet here a lot of people restoring Cizek models, looking for the original sound of these great speakers. I'm doing the same so i'm collecting any informations concerning the customize process (by Cizek factory) of the great tweeter Peerless KO10DT/8 or DT115 before the installation in the cabinet.

Thats because i have two spare pairs of tweeter that i bought many years ago from Coral  (Peerless italian dealer) and I would like to setup these spare parts as a real backup of the original piece moodified by Cizek.

Any info about that can be really useful !

Thank You in advance for help.

Best Regards

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  • 2 years later...

Wow JKent .  I'm blown away by the research and work you did on these.  They came out great.  Kudos!  I clicked on the link that you have here showing the subwoofers.  Now I think I'm loosing my mind. lol.   For some reason,  I remember them having a sub-woofer that could be placed on its side sort of like a coffee table.  Perhaps it was a prototype that never got produced or maybe just these without the attached stand on the bottom.  I just don't remember the subs in a vertical position like your link but there the are.  Thanks for posting this and all your other info on these.  

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