Cornwall Upgrades?

[Klytus]

Hello,

I'm new to this forum and new to the Klipsch experience. Questions: Has Klipsch created an upgrade kit for the Cornwall II ? Has anyone considered using a router and a round over bit around the Cornwall horn openings to create a graduated transition from the horns to the outer surface of the speaker cabinet? Like making the cabinet part of the horn. You probably think I'm nuts now. Also, can someone contact Mr. Crites to learn more about his marvelous products?

I must edit this post. It appears that the Cornwalls are the original Cornwall. The speaker cabinet backs come off and all the drivers are mounted inside the cabinet. The speakers were built in 1976. The Xover looks pretty simple at first glance. Two inductors and two capacitors. Is that enough for a three way speaker?

Thanks in advance regardless of the answer.

[boom3]

The only official upgrade to the CW II is the CW III, which is the current production model. There was a gap of many years between the CW II and the III and no official upgrades were considered.

The CW II used flush-mounted horns, versus the CW I and other Klipsch products of the same generation that used recess mounting. Whatever problems the recess mounting contributed were cured by flush mounting. This would have been most noticable on the tweeter; the midrange probably reveals no diffrence. I'm not sure what you're thinking of by using a "gradual transition" from the horn mouths to the speaker baffle. The only way to do that would be to create a baffle that mimics the curvature of the horn and then folds back, creating an oblate rounded shape. Some pro PA speakers do this to an extent, although I daresay it's just for looks.

The midrange horn, in particular, depends on having the front baffle to support its radiation at the lower edge of its operating range (down to 600Hz). If you read Paul's 1963 paper on the K400 horn, he reduced the mouth size and then restored the lower end by attaching a "flange" (baffle). Just by coincidence, [] that baffle was the same size as the existing K5 horn frontal area, so the esthetics of K-horn barely changed.

Many people, myself included, think the Cornwall's lovely sound is due in no small measure to the relatively large front baffle shared by the drivers, which ensures a stable driver loading at handoff from the woofer to the midrange.

[boom3]

You can PM Bob Crites via the forum. I have one of his CT125 tweeters. I consider it a significant upgrade from the K77 tweeters used in the prior generation Klipsch products. I consider the difference between the CT125 and the K79 tweeter used in the CW II marginal.

[BEC]

Klytus,

You can send me an email at:

bobcrites@mac.com

Bob Crites

[Klytus]

The only official upgrade to the CW II is the CW III, which is the current production model. There was a gap of many years between the CW II and the III and no official upgrades were considered.

The CW II used flush-mounted horns, versus the CW I and other Klipsch products of the same generation that used recess mounting. Whatever problems the recess mounting contributed were cured by flush mounting. This would have been most noticable on the tweeter; the midrange probably reveals no diffrence. I'm not sure what you're thinking of by using a "gradual transition" from the horn mouths to the speaker baffle. The only way to do that would be to create a baffle that mimics the curvature of the horn and then folds back, creating an oblate rounded shape. Some pro PA speakers do this to an extent, although I daresay it's just for looks.

The midrange horn, in particular, depends on having the front baffle to support its radiation at the lower edge of its operating range (down to 600Hz). If you read Paul's 1963 paper on the K400 horn, he reduced the mouth size and then restored the lower end by attaching a "flange" (baffle). Just by coincidence, [] that baffle was the same size as the existing K5 horn frontal area, so the esthetics of K-horn barely changed.

Many people, myself included, think the Cornwall's lovely sound is due in no small measure to the relatively large front baffle shared by the drivers, which ensures a stable driver loading at handoff from the woofer to the midrange.

What I was trying to say is that on a recessed design the dimensions of the horn cutouts never change from back to front but a horn's dimensions continue to change up to it's opening. By using a router on the cabinet horn cutout, the horn cutout would change from back to front, creating a slightly larger opening at the front of the baffle similar to a horn's design. My apologies, the Cornwalls appear to be the original design. All the drivers are mounted on the inside and the back of the cabinet comes off. I'm a novice. I don't even know what I'm buying.

[Klytus]

Klytus,

You can send me an email at:

bobcrites@mac.com

Bob Crites

Thank you, Mr. Crites.

[Janders1954]

I have a pair of Cornwalls purchased in 1979. There is no obvious physical degradation, unlike my pair of McIntosh XL 10s purchased around the same time which had major foam rot 10 years ago necessitating repair. Anyway, I seem to notice some HF roll-off. Perhaps this is because of my 65 year old ears ain't what they used to be. But I was wondering if the electrolytic capacitors in the crossovers may be drifting or otherwise degrading, causing hf degradation. Has this ever been seen? 

Regards;

John A

Moorpark CA

Edited February 29, 2020 by Janders1954
More detail

[Travis In Austin]

On 2/27/2020 at 12:43 PM, Janders1954 said:

I have a pair of Cornwalls purchased in 1979. There is no obvious physical degradation, unlike my pair of McIntosh XL 10s purchased around the same time which had major foam rot 10 years ago necessitating repair. Anyway, I seem to notice some HF roll-off. Perhaps this is because of my 65 year old ears ain't what they used to be. But I was wondering if the electrolytic capacitors in the crossovers may be drifting or otherwise degrading, causing hf degradation. Has this ever been seen? 

Regards;

John A

Moorpark CA

A lot of people replace their crossovers, or replace the caps themselves and report excellent improvement.

 

Travis

[jjptkd]

On ‎2‎/‎27‎/‎2020 at 10:43 AM, Janders1954 said:

I have a pair of Cornwalls purchased in 1979 I seem to notice some HF roll-off. Perhaps this is because of my 65 year old ears ain't what they used to be. But I was wondering if the electrolytic capacitors in the crossovers may be drifting or otherwise degrading, causing hf degradation. Has this ever been seen? 

Regards;

John A

Moorpark CA

Crossovers would be a great place to start but honestly the factory k-77 tweeters leave a lot to be desired in my opinion. Bob Crites sells a drop in replacement the CT-120 that has significantly better upper end extension / response and detail head and shoulders above what's in there you might want to give those a try if new capacitors alone don't fix the problem for you.

[OO1]

-

[jjptkd]

11 minutes ago, Randyh said:

I have the exact pair , 1979 CW and I have the same problem , whereas my 1977 Heresy speakers have no such HF Roll off , it makes the bass boomy and the HF hidden under a veil , news caps are needed in the crossovers , maximum 10$ each - 40$ and 1 hour of soldering and unscrewing- the crossovers and removing  the back covers 

 

Keep in mind that the Heresy mid and woofer output are reduced compared to the Cornwall by 3db which I'm sure helps the tweeter keep up at least a little bit in that application.

[JohnA]

Capacitors that have "gone off" will make the speaker sound dull and distant. 

 

Rounding the squawker opening likely won't hurt.  You'll have to be careful with the cut to protect the screws.  Try lining the opening with heavy felt. 

 

Changing the tweeter to a tractrix horn that is flush with the front of the motherboard will clean up some hashy sounds from the tweeter. 

[Marvel]

I mounted my La Scala K-400 horns from the front. It required making the opening a little larger, but it worked out well.

 

Bruce

[glens]

1 hour ago, JohnA said:

Capacitors that have "gone off" will make the speaker sound dull and distant. 

 

And by "gone off" doesn't mean the capacitance has changed.  Likely that value will still measure well-enough using a DMM so equipped to measure.  Rather, there develops over time an increased overall effective resistance, which most DMMs will not portray.  It's like having a resistor in series with the driver as well, so the output will be reduced across the board.

[glens]

1 minute ago, Marvel said:

... it worked out well.

 

Did you feel it was worth the effort?

[Marvel]

Don't know the answer to that. It wasn't hard, but I was outfitting these cabinets that had all the wrong parts in them. What probably made more of a difference was cleaning up the casting of the horns. There were ridges where the molds were deteriorating to where there was flashing and so on, on the inside of the horns.