Kornmach III

biamped

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I saw a craigslist ad 2 days ago for "Huge speakers-$260" which looked like Cornwalls. Of course I immediately replied and negotiated (of course) the price to $200 sight unseen other than the listing picture.
Next day, drove 50 miles for the pickup and hauled them home.
One of the woofers was an obvious replacement so I opened that cab first. Disappointment set in when I saw the other speakers were replacements also. After some research, I determined the cabs were 3" shorter than Cornwalls, other dimensions the same.
Now I have parts from a Radio Shack Mach three and will begin the conversion of this cab into a
" Kornmach". Should be a fun project!
Any comments/advise is welcome.
John
 

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That's bizarre, sure look like Cornwall's .. were the mids and tweets Klipsch? Looked for serials or makers marks on the cabs? Might want to be sure before you do any cutting...
 
That's bizarre, sure look like Cornwall's .. were the mids and tweets Klipsch? Looked for serials or makers marks on the cabs? Might want to be sure before you do any cutting...

There are no makers marks on the cabs, only penciled marks for speaker placement although one cab had a Klipsch K22R woofer installed. I think the whole was an effort at a Cornwall clone. Mids are fiberglass horns with large drivers having no name or part number. Tweets are marked Motorola. Crossovers are rudimentary 3 ways attached to the binding post mount. I must say, the cabs were well made 32 x 21.5 x 15.5", slightly smaller than the dimensions I found for Cornwalls.
 
At least the cabinets are worth something although I'm not sure they're worth $200. Oh well, like you said it should be a fun project.
 
Currently, I have Mach three woofers to be reformed, or Utah MH15R3R as woofer alternatives. The mach three crossovers would be modded as per VL and others advise. I modded some Mach twos last year with good success after changing the mid to a nice dome. They thump!
 
At least the cabinets are worth something although I'm not sure they're worth $200. Oh well, like you said it should be a fun project.
If these cabinets were someone's project, I'd say they succeeded in creating a close clone of the Cornwall I or II. The Cornwall III's woofer is placed higher and the mid and tweeter horns are closer together than the I or II's. If they were in great condition and matched the Cornwall's dimensions, they would be worth about two bills or more.

By the way, the Cornwall III measures 38" x 25.5" x 15.5"
 
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That grain is nice and actually the smaller size may be an advantage. I've owned Cornwalls and as you know they're a pretty healthy sized speaker.
 
You have 4.9 cubic feet there. A pair of JBL 2235s and the Deluxe top end from the Econowave and you really have something there.
 
I could swear VL came up with 4cuft for the Mach One, as ideal, for a sealed enclosure. Are your cabinets sealed or ported? If ported turnitdown might be onto something. Though I have to say there are possibilities with the Mach II-III woofers since the cabinets they were in were undersized.
 
I could swear VL came up with 4cuft for the Mach One, as ideal, for a sealed enclosure. Are your cabinets sealed or ported? If ported turnitdown might be onto something. Though I have to say there are possibilities with the Mach II-III woofers since the cabinets they were in were undersized.

As I started thinking of options, the comment that the boxes were too small for the Mach II-III woofer surfaced. From there, the merging of the Mach low end into the ported Cornwall box with the Klipsch mid/high evolved. To that end, I have just bought a pair of used k400 horns and selenium drivers. Mach III crossovers and woofers are in stock but I have not settled on a tweeter. Possibly a T35 from an old Klipsch. The crossover may need tweaking as the project evolves so I will be seeking technical advise for mods.
I am hoping to develop a thumping Mach with a more refined upper register.
 
Did you listen to them as-is?

How do they sound?

One speaker had a good 12" Klipsch woofer and working mid and tweeter. It sounded muted and had very little bass for a 12" speaker. I think the woofer was more suited to a closed cab. Speaker 2 had a blown woofer. The crossovers are a unknown item. I'll post a picture tomorrow.
 
For a 12" existing opening you might consider the Nova 5b or Optimus 8b woofers. But the cabinets will most certainly have to be sealed. As for Tweeter, the one in the Mach Two has always been highly regarded, however, you will need a mid that reaches up high enough to cross over with that tweeter. I believe the selenium might be able to do that, provided you cross it over around a 1000hz or so on the bottom end. The Mach Two woofer I believe is good beyond 1000hz, and I'm totally confident the 5b/8b woofer will do so comfortably.
 
For a 12" existing opening you might consider the Nova 5b or Optimus 8b woofers. But the cabinets will most certainly have to be sealed. As for Tweeter, the one in the Mach Two has always been highly regarded, however, you will need a mid that reaches up high enough to cross over with that tweeter. I believe the selenium might be able to do that, provided you cross it over around a 1000hz or so on the bottom end. The Mach Two woofer I believe is good beyond 1000hz, and I'm totally confident the 5b/8b woofer will do so comfortably.

The current plan is to enlarge the woofer opening to accept a 15. Either the Utah(Altec), or a modified Mach 3. The box is certainly large enough. Have you heard Mach 3 tweets?
 
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