Improving Cornwall I crossovers

[BEC]

Terry,

I think the II designation may have gone away in the early 70s. That may be the time that Andy said all verticals became special order rather than a stocked speaker. My 1972 Cornwall Vert just says "Cornwall" but it has the little red arrows on the back.

Bob

[Clipped and Shorn]

"The networks are on loan, and were built by Dr. Pipes as the ALK 600 ESN.

That ugly stuff sits atop a heavily braced CW bin with BEC cast frame 15" woofers. 511b/902-16a mids and the JBL 2404's on top

.
My preference is to cross the mids a bit lower, but the ESN 600 has
opened my eyes to slopes. As to the design limits of PWK's reflex, I
think that I have pushed (with much help) the single woofer Cornwall
design to it's max. Make no mistake, they are kicking my a**!"

Referring to Al's posted information, I would assume this to be his AP12-600 mentioned below:

AP12-xxx crossover network notes

----------------------------------------------------------------

These networks may be built for your own use only. ALK Engineering

reserves all rights to build them for sale.



This series of networks are intended to be economy woofer / squawker

crossovers for use with the ES5800 extreme-slope squawker / tweeter

crossovers. They are gentle slope designs having 12 dB / octave slopes on the

high output and 18 dB / octave on the woofer. This is because the voice coil

inductance of the woofer driver is integrated into the woofer filter as a

third inductor forming a 3rd order filter. Therefor the woofer driver should

be the Klipsch K33 found in the heritage series speakers (1 mHy in series

with 6 Ohms).



There 5 designs to choose from:



AP12-AK3 - This is to be used only with Klipschorns that have the AK-

3 network installed. The components that are located inside the woofer hatch

are be reused as they are correct and are identical to those used in the

AP12-350 network design.

AP12-350 - This is a 350 Hz crossover intended for the Klipschorn. It

may be used in a LaScala when used as a center channel between Klipschorns.

AP12-500 - Crossover is at 500 Hz and is intended for the Belle

Klipsch or LaScala.

AP12-600 - Crossover is at 600 Hz. This one is intended for use in 2-

way systems using drivers that will not safely go down to 500 Hz.

AP12-700 - Crossover is at 700 Hz and is intended for use with the

Altec 811b squawker horn.

All of these networks are compatible with the ALK Engineering

Trachorn squawker horn upgrade.



The network will operate in a 2-way system using the autotransformer

to equalize the level to a wide range driver such as the Altec 902-8 with the

woofer using the 2-way strap. By removing the 2-way strap an external

crossover can be connected to transition between a squawker such as the

Klipsch K55V or K55M and a tweeter in a three-way system. The squawker can

utilize the same autotransformer. Three-way operation is recommended as not

many drivers will operate safely from 500 Hz up.

[jwc]

"Anyway, love the ESN for the CW, or "Alcorn" as I call them. The steep slope cures many ills for PWK's reflix. (IMHO) "

Sorry to be so dense, but what is ESN ? Is that another term for the ALK crossovers I have been considering? Extreme Slope Networks???? just guessing.....

-Sneezed and Coughed

IBSlammin has the cat's meow of network for the Corn. Over the top really.

It is an Extreme Slope network designed by Al Klappenberger. It actually isn't a ESN600 but an ESN700. It also has a custom bandpass for the squawker and tweeter filter for 3 way.

There isn't much more Terry can do to upgrade that Corn except to start over with a new speaker. I had the opportunity to hear this setup.

It has been a little while since I had heard the Altec 511. Loaded with Altec 902. Tube CD and Tube pre with massive SS amps.

Very Warm. I never got this warmth from my system before. Highs from the JBL are as I remember...very good. The bass was just fine.....very strong. Typical Cornwall bass with authority for sure. Well set up.

I have listen to my La Scalla 2's for awhile and the bass was different for sure.

I think the ESN's work well for the Cornwall. I had them in my Cornscalas before I gave them to Terry. I went through a bunch of networks and that setup with ESN is the best. I even had the ALK B built by Dean in there. That was the second best. I would recommend the ALK B to anyone.

I would love to see the ESN setup in a Cornwall but that is a lot of XO real estate. Tough to fit.

jc

[Clipped and Shorn]

With all of those variations available to diy tweak the ALK crossovers for use with different drivers, even Altec 511b horns and 902 drivers, if only there were enough information available to use a substitue for the Klipsch woofer, something like the Altec 416B. If only. Then one would not have to scrounge around for old vintage overpriced Altec and JBL crossovers.

There could be a obvious niche market!,

eg. to provide a classy ALK type crossover for use with an Altec 416 woofer, a 902 driver with 511b horn, and a JBL 2404H tweeter.

I would have bought at least a half dozen by now. Instead, I am bi- and tri- amping and using electronic crossovers, which turns out to be pretty cool in itself, except for running so many amps.

Apparently using an Altec woofer is a whole other ball game. I am not enough of an engineer to figure that stuff out, and the genius available at Parts Express cannot or won't do it either. For my diy Valencias, I just ended up scrounging around for vintage crossovers because information or schematics not available for diy crossovers using those components.

For the Cornwall upgrade,on the other hand, I will retain all of the original Klipsch drivers, and look forward to using the ALK design Xvrs.

-0purtjsgadfnlmascvg & mcvzxmndoi

[jwc]

Well. It's all a function of time and money...as my Dad says.

If you have a particular woofer you want to use, you can send it to me. I can get the measurements that ALK needs and he can design everything based on that. I've done this a few times with him. Works great.

Cost you though....you would have to love that woofer!

jc

[Clipped and Shorn]

"IBSlammin has the cat's meow of network for the Corn. Over the top really.

It
is an Extreme Slope network designed by Al Klappenberger. It actually
isn't a ESN600 but an ESN700. It also has a custom bandpass for the
squawker and tweeter filter for 3 way."

Al's info suggests the Altec 811B, I am wondering if there were some additonal slight mods to his chart of vallues when using the larger 511 horn instead?

-uhisdfuiydsf & ljkfadlkj

[jwc]

The "intent" with the ESN700 was to use with the Belle as the 811 will ount in the Belle as he used to have it.

But....

As long as the woofer is a K33 or one of Bob Crites woofers, you can use any of the ESN's. The top horn or driver really don't matter as lond as they don't need EQ....that isn't done in the network.

So use the 511 instead of the 811. I've used both. The 511 sounds better. mid driver and tweeter of choice. You could use the ESN500 with the 511 if you want.

jc

[Clipped and Shorn]

Remember I was rip vanwinkling for awhile so bring me up to speed: what is the Bob Crites woofer??? Bob, how does someone make a woofer. Fini told me how good you were (he's got your upgrade in his Khorns), but making woofers, wow......didn't there used to be a song about making woofers....oh that was whoopies.

-kljasdf kljfdk & jklsadfkjlsadf

[JJkizak]

Clipped & Shorn:

Yes, with the non-elegant SS Denon. I thought (if you can remember how a speaker sounded 40 years ago) that the improvement in balance and voice reproduction was remarkable with the new network. My hearing range then was 40 to 16.4 khz, now 19 to 12.5khz. I also use the Cornwall as a powered center channel and it just does not barely fill in but with the Denon set to PLC-II it blows you away with the sub about 3 ft away from it. The Denon 7.1 choked when I tried to run the K-horns and the rest of the speakers so I used the old Denon slaved to the new Denon (as a pre-amp) to drive the k-horns. The small 5.1 side speakers filled in some nodes on the high and low end (don't use 7.1) This setup allows all kind of volume tweeking between the K-horns and the center channel with the equalizer and expander/compander only in the K-horn feeds. I used the SPL meter to set them all at about the 98 db level which does allow for humongous peaks in bass and treble. The K-horn bass fed by the equalizer (+6 at 30hz,) and the bass control (+3/4 point) with the expander/compander just starting to function throws a huge amount of power into the bass section. The treble at +10 is a real ear drum cutter when the drummer creams those cymbals. The old Denon receiver had a heck of a lot more reserve (55 watts)than the 7.1 (100 watts) You might say I embelished this system way too much but that's what semi-fanatics do sometimes.

JJK

[BEC]

Remember I was rip vanwinkling for awhile so bring me up to speed: what is the Bob Crites woofer??? Bob, how does someone make a woofer. Fini told me how good you were (he's got your upgrade in his Khorns), but making woofers, wow......didn't there used to be a song about making woofers....oh that was whoopies.

-kljasdf kljfdk & jklsadfkjlsadf

To make a woofer (at least in my case) one commissions a woofer manufacturer to build a woofer to a set of specs. Once the woofer manufacturer has produced a prototype woofer meeting those specs, then you have to buy some minimum number as a production run. That number in this case was 50 woofers.

Bob Crites

[jwc]

Bob's woofers work great. "electrically" behave like a K33. Used them several times for DIY.

jc

[Deang]

"...and 18 dB / octave on the woofer. This is because the voice coil inductance of the woofer driver is integrated into the woofer filter as a third inductor forming a 3rd order filter...1 mHy in series with 6 Ohms..."

I've tried, but I just can't buy into that.

[jwc]

I sure don't have to understand it completely....or argue that concept.

Sounds good to me.

jc

[Clipped and Shorn]

"...and 18 dB / octave on the woofer. This is because the voice coil inductance of the woofer driver is integrated into the woofer filter as a third inductor forming a 3rd order filter...1 mHy in series with 6 Ohms..."

I've tried, but I just can't buy into that.

Thanks Dean, I knew you must have had an informed reason for your decision. I was going to take your advice anyway.

-uiotewr & tyuqwe

[Clipped and Shorn]

It was mentioned that other people have found that the K-55 squawker (with push-in terminals) to sound a bit harsh. What have been some other solutions to this? I already know about people replacing with Altec components and I am not interested in that route for this project. I just want to preserve the Cornwalls but fixing the harshness. Has anyone replaced this K-55 with other Klipsch squawkers that fit right into the slot? Or is the best way to deal with this, the ALK crossover which we have already discussed.

I have not ruled out the depressing yet remote possibility that the ALK crossover may not fix the problem, and someone has mentioned to me an individual who tried the ALK in his vert Corns and consequently rejected them in favor of keeping the old type B. Maybe that had to do with his using McIntosh tube amps and old mono LPs. Currently my plan is to diy the ALK Xvrs (need to economize at this point, and anyway I have some extra solder and plywood scraps on hand) and then use the Corns with SET 2A3 amp. I seem to recall past testimonials by those using essentially this type of gear. Anyone remember if Kelly's (vert) Corns had original or upgraded Xvrs?

I have to admit that all these Altec subs for the Klipsch mids is not the best recommendation. I already know how good the Altecs sound (*Bonnie buys crap coffee so I know how good my coffee is since I buy it), and I have them everywhere and listen to them all the time. My goal here is to justify these dmnd Cornwall$, finally.

-p[oiuyp[o & ghjrewqhg

(*the Bonnie situation)

[Clipped and Shorn]

Listening to Zeno's Alecs....hmmmm goood!

Now we need to dispose of his Cornwalls, and if I am not mistaken the clock is ticking, is that right gentlemen?

(lot's of cream, lot's of sugar....)

[Deang]

Since you're only going to be running 2A3, I don't think hashness will be an issue. I've owned Heresy's, Cornwalls, and Klipschorns -- and the only time harshness came into play with the low order filters was when I was pushing the volume. The narrow thoats of the old horns just don't handle power gracefully. Since you're going to be using a 2A3 amp with the Cornwalls, I would stick with the Type B -- that combination is a proven formula for low level listening enjoyment. I like the ALKs, but they are best suited for moderate to louder volume listening. When I started embracing lower level listening, I went to the Type A in my Klipschorns and sold my ALKs. Since you were willing to spend a little money, I would build up new Type B's from the ground up. Get new Autoformers from Bob Crites, and splurge a little and get the OIMP V-caps from VH Audio. There's a lot of voodoo over there, but the caps are killer.

[Clipped and Shorn]

Since you're only going to be running 2A3, I don't think hashness will be an issue. I've owned Heresy's, Cornwalls, and Klipschorns -- and the only time harshness came into play with the low order filters was when I was pushing the volume. The narrow thoats of the old horns just don't handle power gracefully. Since you're going to be using a 2A3 amp with the Cornwalls, I would stick with the Type B -- that combination is a proven formula for low level listening enjoyment. I like the ALKs, but they are best suited for moderate to louder volume listening. When I started embracing lower level listening, I went to the Type A in my Klipschorns and sold my ALKs. Since you were willing to spend a little money, I would build up new Type B's from the ground up. Get new Autoformers from Bob Crites, and splurge a little and get the OIMP V-caps from VH Audio. There's a lot of voodoo over there, but the caps are killer.

So would I keep all the values the same on the new parts? Is there a schematic posted somewhere for the Type B. I do realize it could be as simple as physically following the units I remove from the cabinets on hand. By the way, I am currently using this 2A3 amp with my diy Valencias and the problem is not getting volume so much as the harshness that comes with this increased volume (moreso even with the less powerful 45s -- one simply has to remember to be satisfied with the optimum volume level and not let one's musical excitement and enthusiasm escalate those levels), even with the Valencias which use the 811 Altec horns. But, I like your nformed suggestion of keeping the Type B design (since you have knowledge of this situation), building new from scratch with proven boutique parts. What is "wrong" with the old autoformers in there? Just curious, I am definitely open to getting new parts, just wondered if Bob's are an upgrade or if the old ones actually do "wear out".

-asdrasrd & trewtrwetr

[Clipped and Shorn]

To B or not to B, that is the question.

To B or to ALK-B, that is the question.

To B, or not to B: that is the question:
Whether 'tis nobler in the ear to suffer
The slings and arrows of outrageous squawkers,
Or to take tubes against a sea of troubles,
And by single-ended end them? To ALK: to recap;
No more; and by a recapping to say we end
The ear-ache and the thousand natural shocks
That audio is heir to, 'tis a consummation
Devoutly to be wish'd. To upgrade, to modify;
To modify: perchance to remedy: ay, there's the rub;
For in that mod of electrons what sounds may come
When we have shuffled off this mortal Litz coil,.....

excetera eXcetera Nucular Ecksetera ...........

-yrueiqo & jgfkal

[Deang]

That poem is good enough to print and frame! [Y]

"So would I keep all the values the same on the new parts? Is there a schematic posted somewhere for the Type B."

Use the same values, schematic attached. I suggested replacing the autoformers because the winding on the originals is often not tight on the core anymore. Even so, the new ones have a bifilar winding and are a better built product all the way around. A pair will run about $70, which isn't to bad -- and if you're going to take the time to rebuild a network I don't see much point in going half way. Use part number 266-908 from www.partsexpress.com for the woofer coil.

"...I am currently using this 2A3 amp with my diy Valencias and the problem is not getting volume so much as the harshness that comes with this increased volume (moreso even with the less powerful 45s..."

You might be driving the amps into clipping. If that's true, then going with the ALK B will only have you going into clipping sooner.