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Cornwall I Mods - 1 More?

I would start moving my speakers around and my listening poition for better bass reproduction. You need a pink noise App to plug into your amplifier and a great Sound meter App for your iPhone. Mine works great with the iPhone 15 pro using the Decibel X app. I wouldn't depend on the response above 10 KHZ, but the response is very close to my spectrumn analyzer below that frequency. Just make sure you place the bottom of the phone toward the speakers and keep the phone away from your body. I use a large clamp on a Beyer tri-pod mic stand. You can change your bass response curve sometimes by over 10 db by moving things about a bit. It used my spectrum analyzer and it sure help me smooth things out. Then I just had to use a very small amout of LF emphasis on one channel because the room was not symmetrical and an opening of the left side to another room was reducing the bass out put on that left channel. See the computer screen thru the opening on the extreme left. Thats the Where I am sitting at the moment.IMG_4038.jpeg
 
OK, All, this is for your consideration. All criticisms, comments, suggestions, etc. welcome and requested. My Cornwall 1s have only one real modification, that being changing out the K77s for a pair of Dave's DE120 SMAHLs. I've also been playing around with ALK's B replacement crossover for the Cornwall and heard comments that the first version was the one to go with. I've read a lot that moving the crossover for the mid to the tweeter down to 4500 would be a good thing with this combination. Please let me know what you think about the attached crossover schematic. Will this work? It would be good to know if any adjustments need to be made prior to actually building it.

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Thanks
 

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Were I to modify an older Cornwall I'd replace the woofer with an Altec 416, do whatever it takes to blend it properly and leave the rest alone. Then you'd get much of that magic Altec Technicolor midrange, much of which comes from the woofer. You could crossover at 1200 cycles like in the Model 19 if you wish and get more of the woofer's goodness while easing the load on the midrange driver and horn. IMO good midrange and vocal reproduction is the key to a good speaker.
 
I'm waiting on an impedance plot of the K33 in a Cornwall. Not sure how Al came up with that woofer filter. Also, not sure why he opted for a 5 ohm load on the high pass filter to the autoformer. Are you willing to reuse the 2.5mh inductor and the T2A autoformer or do you want to start from scratch?

I've also simplified the low pass to the squawker. I'll post my suggested schematic when I get the K33 impedance plot, unless someone already has one for a K33 in a Cornwall cabinet.

Mike
 
"replace the woofer with an Altec 416" I'm not familiar with that woofer, however, it's an intriguing suggestion.

Mike, I've run simulation plots on Al's early and late iterations of the low pass he used in his B Replacement xover and the early one looked a bit better to me. Just a tad more energy delivered down low for the 1.3 mHy version, otherwise, very close. I do still have the original Klipsch parts and I also have the parts from Al's second version of the B Replacement xover along with most of the parts for the first version. The only thing I lack for the suggested schematic is a real 500 uHy Litz coil, but I do have one at 510 uHy. I thought that that might be close enough.

Can't wait to see your K33 results. No pressing need to get this done immediately, just like to plan ahead. You know, measure twice, cut once.

Steve
 
Steve Dinse said:
"replace the woofer with an Altec 416" I'm not familiar with that woofer, however, it's an intriguing suggestion.

Mike, I've run simulation plots on Al's early and late iterations of the low pass he used in his B Replacement xover and the early one looked a bit better to me. Just a tad more energy delivered down low for the 1.3 mHy version, otherwise, very close. I do still have the original Klipsch parts and I also have the parts from Al's second version of the B Replacement xover along with most of the parts for the first version. The only thing I lack for the suggested schematic is a real 500 uHy Litz coil, but I do have one at 510 uHy. I thought that that might be close enough.

Can't wait to see your K33 results. No pressing need to get this done immediately, just like to plan ahead. You know, measure twice, cut once.

Steve
Click to expand...

I'm curious what your plots show. One of my concerns is that they may be based on a 4 ohm load. Looks like it's closer to 7 ohms at 600hz.

Screenshot 2025-05-16 151314.png
 
Tom Brennan said:
Were I to modify an older Cornwall I'd replace the woofer with an Altec 416, do whatever it takes to blend it properly and leave the rest alone. Then you'd get much of that magic Altec Technicolor midrange, much of which comes from the woofer. You could crossover at 1200 cycles like in the Model 19 if you wish and get more of the woofer's goodness while easing the load on the midrange driver and horn. IMO good midrange and vocal reproduction is the key to a good speaker.
Click to expand...
My goodness! I just looked up the Altec 416. $1,100 per driver!
 
After doing B2 & Crites HF on my CW, I kinda came to where you guys ended-up on Heresies--get a different speaker. It's fascinating to see what people like/dislike about all of the Klipsch line. For me, I had lived with ewaves for a while by the time I got the CW and there just was no chance to swallow the beaming anymore. It could've had 515's or 416's or whatever--for me, it had to go because butchering a CW baffle is...not the right choice.
 
Honest answer is nothing. Moved. Different life, different house, different everything. Mostly computer listening now, routed through a table radio until I figure this out. Simplifying. Kept the Georgians and maybe 5 other pair of lesser things that still do something for me.
g600_col_cane.jpg

They get signal maybe once a week tops when in need of a dynamics fix.

I will always have a soft spot for Cornies and, if I'd kept them, they'd be hooked-up to the computer right now :)
 
mboxler said:

I'm curious what your plots show.

I never saved the original plots, however, I ran the same combinations on Xover 3 using the following parameters for a K33.

View attachment 3505800

Results:

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Looks to me like 200 to 600 is better on the 1.3, although this is theoretical and my methods may be all wet. I'm NOT an audio engineer. :confused:
 
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