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The Ultimate Cornwall Mod / Derivative - Tom?


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So what, Tom, you your opinion, would be the perfect Cornwall configuration, using the cabinet but with any mid and top combination. In fact, if you have the time, suggest:

1. Ultimate Cornwall using JUST the cabinet (all drivers/horns must mount within but any combo can be used)

2. Ultimate Cornwall using cabinet for bass, but with any horn/driver combo inside/on top/out.

Interested in your opinion here.

Also, what horn combo could be used that would take the same space/footprint as the CW but be a significant upgrade in smoothness / musicality?

Know it's a big question but curious. I would even prefer if you narrowed it down to the actual driver/horns you would use instead of a liste of say 10 units. Any others can chime in if so desire.

kh

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Phono Linn LP-12 Vahalla / Linn Basic Plus / Sumiko Blue Point

CD Player Rega Planet

Preamp Cary Audio SLP-70 w/Phono Modified

Amplifier Welborne Labs 2A3 Moondog Monoblocks

Cable DIYCable Superlative / Twisted Cross Connect

Speaker 1977 Klipsch Cornwall I w/Alnico & Type B Crossover

system one online / alternate components / Asylum Listing f>s>

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Mobile---I played around alot with the last pair of Cornwalls I owned. I ended up with the mods shown on my website: the stock mid horn replaced with the tractrix mid horn from the KPS 301 and the tweeter moved to the outside surface of the cabinet. This sounds very good, the guy who now owns them, an experienced horny with whom I used to build homebrew LaScalas and VOTs, really loves them. Caveat---Berenek's Law states that if you build a speaker to ideas that you think will sound good the resulting speaker will sound good to you, same goes for mods. I also used the CWs as bassbins only with Altec 806s on 511b horns mounted atop the CWs, crossed at 500hz. To me this sounds better than a CW; Altec midrange is much smoother and natural sounding, the highs are smoother too though a little soft compared to the CW's. Altec 806s, 802s or 902s on the 811B horn, crossover to woofer at 800hz, would fit inside the cabinet. I think the ultimate use of a CW as a bassbin would be with a JBL or Altec 1" driver on a Edgar "saladbowl" tractrix horn. If one crossed at 700hz the saladbowl would fit inside the cabinet, if one crossed at 500hz the then larger Edgar would probably have to sit ontop. For those that find the soft highs of 2-ways using 1" compression drivers unacceptable then the use of a good horn tweeter like a JBL slot, catseye or buttcheek would be in order, bring the tweeter in around 10,000hz. Now these are my opinions and experiences Mobile, my taste, these are not intended as statements of fact. But part of the fun of horns is how easy it is to substitute drivers and horns, this is much easier if one uses an active crossover which allows easy adjustment of crossover points and driver levels. Lots of used Altec, JBL and EV stuff is available used at resonable prices and the members of the Horn Brotherhood are REAL good on loaning stuff out and giving stuff away. Any serious horny needs a collection of horns and drivers to play with. This is where Klipsch and Klipschies are a little different, Klipsch sold turnkey systems that people pretty much install and leave alone. JBL, EV and Altec encouraged the DIY approach and sold drivers, crossovers, enclosures and made enclosure plans available. They encouraged a "building block" approach to horn speakers, the result is that Altec, EV and JBL hornies seem more adventurous and willing to try different things. (Like Paul Eizik with his DIPOLE EV horn rig, wild) The bad side to this is that you can end-up, like me, with your speakers in a constant state of change: using Altec 806s on 511bs one day, a week later using JBLs on Edgars and the next week different JBLs on McCauleys or JBL lenses. In the past 6 months I've used 4 different bass setups: K-33s in Peavey FH-1 basshorns, then JBL LE-15Bs in JBL 4560 basshorns, then Altec 515Bs in the 4560s and now the 515s in Altec 825s. And they all sounded good but the LE-15s in the 4560s were kinda boomy. Well it's a journey. I must say though that I've left my current rig alone for a couple of weeks now and have no yen to change, I may be there. :-)

This message has been edited by TBrennan on 02-02-2002 at 04:02 PM

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MH-I don't know what your going for here but you honestly cannot believe that the Cornwall cabinet is of sufficient construction quality to go to the expense of outfitting it with high quality/high output drivers?

The last time I checked the rear panel on that boom box I couldn't belive how badly it jelly-fishes. A

McCauly or Beyma would cause it to walk across the floor!

This message has been edited by John Warren on 02-02-2002 at 02:27 PM

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First of all, a many thanks to Tom and others for a rather involved question. Mr. Warren does seem a bit over concerned about his Jelly Fishing Cornwall bass bins doing the lowly foxtrot... Perhaps he had a 300w Phase Linear amplifier as its partner with Mahler offering a hand. Or perhaps The Dead Boys circa 1975? Alas, I am sure he will chime in down the road.

Mr. Stehr, I am not ready to cannibalize my poor Cornwalls just yet; they sound too good with 3.5 watts of purity, something some might grasp, others might gasp, and many more might pass. Surely the Jelly Fish have it.

I have been curious about the horn and its many faces. And in all honesty, I will probably go down that ugly path sooner or later... I guess to continue to push the envelope, only the envelope is a thankyou note.

Less is more, more or less. I currently have no room (quite literally) to partake in the full horn selection orgy, but I see it coming full tilt in the future. I might head to the horn fest to sink one more step into that __________ .

Despite Mr. Warrens amusing retort, or perhaps because of it, I am off to listen this evening. mdeneen and ole Tom have said enough to make me curious enough to head west, mid to be more specific. That is the goal. Who knows the outcome.

Off to Coltrane and Stiv Bator....Bill Evans and Bill Callahan.

Thanks again. Tom and ole mdeneen especially.

kh

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

Phono Linn LP-12 Vahalla / Linn Basic Plus / Sumiko Blue Point

CD Player Rega Planet

Preamp Cary Audio SLP-70 w/Phono Modified

Amplifier Welborne Labs 2A3 Moondog Monoblocks

Cable DIYCable Superlative / Twisted Cross Connect

Speaker 1977 Klipsch Cornwall I w/Alnico & Type B Crossover

system one online / alternate components / Asylum Listing f>s>

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thnaks for the question, mobile, I am not headed that way just now, but I think I will be soon, the more I listen to cones, the more I realize how much better the horns are, though Klipsch are the only ones I have ever heard -

Tom, where do you find the Altec horns?

which one would be the best match for the JBL 4638 bass bins?

the Altec and JBL models are not familiar to me, is there a qucik refernce list somewhere?

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Colin's Music System Cornwall 1s & Klipsch subs; lights out & tubes glowing!

This message has been edited by Colin on 02-03-2002 at 12:34 AM

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Colin--Altec 802,806 or 902 drivers on 511B horns crossed at 500hz should sound superb. Stay away from 807s and 808s unless you intend to install aluminum diaphragms. As the real Altec-Lansing gear is no longer made (killed in 1998 in the Telex-EV merger) you have to buy used or NOS. Good sources are ebay (tons of it), prosound stores, the want-ads and Jammin Jersey. Jammin Jersey is a California prosound shop that sells mail-order, they have a very complete website and sell used Altec, JBL, Gauss, Emilar and TAD. Prices are fair and sometimes cheap. They sell a pair of 511Bs in the coveted hammertone green finish for about $200. Black ones are cheaper yet. ALL Altec drivers can be repaired. Bill Hanuschek, Altec's last head engineer, bought the tooling and makes parts on the original machines using original methods. He supports ALL Altec drivers and his prices are VERY reasonable. His company is Great Plains Audio in Oklahoma. For info on old Altec and JBL goods including many old catalogs go to www.audioheritage.org Also the Altec info at www.soundpractices.com

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Okay, the '95 Chorus II's have a K-61-K

90 degree x 40 degree midhorn.

It's a 1.5' Phenolic compression driver.

What benefit if any would there be if you used a 1.5' Titanium diaphragm in place of the phenolic diaphragm?

Or does ferrofluid play a factor between these two diaphragms.

Could you use the Titanium diaphragm and magnet assembly with the 90x40 degree horn?

Curious.

THANX!

This message has been edited by mike stehr on 02-03-2002 at 03:57 AM

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mdeneen-

I noticed your enclosures housing the Altecs. They look fantastic! No substitute for cubic inches. If you have pics of construction in progression please post.

"Jelly-fishing" is a term to discribe panel resonance. Think of how a jelly-fish propels itself thru the water---structural panels that are excited by cyclic systems oscillate in the same way. The larger the panel, the larger the amplitude of the oscillation. Jelly-fishing is a parasitic loss mechanism. Work done by the driver, wasted by resonating enclosure panels, adds noise and robs

he system of LF performance potential and transient capablility. One fix is to brace, placing the brace at the location on the panel of maximum amplitude, usually the point were the diagonals cross. For the CW the brace can tie the front baffle to the back panel rigidizing both. The secondary benefit of cast woofer baskets is to stiffen the baffle board and resist jelly-fishing. The CW uses a low cost woofer that employs a stamped metal basket.

It is silly to be concerned about the sound of speaker wire when the speakers you are listening are driven into spurious resonance associated with panel vibration. The CW is known for being a "boom box" when driven to high SPLs. For SET amps that produce

power with a thermal equivalent of a "flea fart" that might not be such a big concern.

ps-as is evidenced above and, unlike another on this thread, I've managed to get my ideas across without having to resort to cryptic prose feathered with a dash of "subtle whimsy".

This message has been edited by John Warren on 02-03-2002 at 08:49 AM

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Straight ahead you are, John. I know what the term Jelly-fishing is and was mainly playing with your rather taxed sense of humor it seems. I have the article by Roger Floth via Speaker Builder on the mods that can be done to the Cornwall cabinet through bracing, stiffening, and strengthening. It is an interesting piece that outlines the construction text and diagrams (Thanks, Chris). I am considering posting this article on my website as some might find it very worthwhile.

As for the amplification isse, to be succinct, I am willing to bet you have never even HAD a single-ended triode amp of any consequence IN your system, at least not one with a proper power supply. Your preconceptions ring with fancy guess work based on circa 1974 Stereo Review analysis. Your assessment of the meaning of watts rides right alongside the masses who purchase at Wal-Mart and SAMS. I wonder if you were listening to a 20hz test tone through your 200w SS amps while gently massaging the rear of your boom boxes... Just interested, what year were your Cornwalls? In all seriousness, I imagine the CW bass definition might be improved via some strengthening of the cabinet; on the other hand, I have noticed that cabinet resonances can lend a certain alive feeling to the reproduction. I used to work hard on deadening my cabinets for other speakers and found that too much would change the tone and diminish the sense of air. Of course, this idea of deadening is a bit different from strenghtening, but I was just making the comparison. In general, a strong, rigid cabinet is always a good thing.

What is your current setup, John, all whimsy aside?

kh

This message has been edited by mobile homeless on 02-03-2002 at 10:07 AM

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although I dampened my CWOs with large paving stones, I beleive the big old horns were supposed to resonant with the music, the Khorns that I heard did and the result was magical, as if the speaker was a musical instruement itself, not merely a reproduction device -

Tom, which JBL bassbins would you match with the 806s?

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Colin's Music System Cornwall 1s & Klipsch subs; lights out & tubes glowing!

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mdeneen-

good to see some cross-bracing on those large panels.

On your next project, turn the 2x4s 90 degrees (the 1.5" thick side would then be the side that mates

with the panel). The stiffness increase is maximum.

You have to drive screws into them from the outside. Did you paint both mating surfaces with glue? I prefer Tightbond Liguid Hide glue, slow to set and won't crack with aging.

mh-

My current setup (the one I listen to most) is a

Philips Magnavox AZ1110 CD Radio Cassette Recorder with DBB (Dynamic Bass Boost). It has a built-in handle and a dettachable line cord that I find quite convienient. I'm thinking of swapping out the line cord (18AWG/2C) with a 14AWG/3C.

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mdeneen, the clarity issue that you mention is the #number one reason why I would build a more rigid cabinet, aside from the bass issue. And this would apply across the board as well, especially if your tweeter and mids were attached to the same structure as the woofer. Imagine the vibration that goes along with this. This is also the reason that many move their crossovers OUTSIDE the cabinet to escape the resonance problems and the subsequent blurring and loss of fine detail or clarity.

Still, I dont know if I would do such a drastic mod to the Cornwalls as it would literally kill any resale and also diminish a bit of what they were in the first place. I think the best thing to do would be build a new enclosure altogether as you have done. I have a good woodworker/cabinetmaker buddy who has expressed interest in building some enclosures after hearing how good my system sounded. He had never heard horns of any kind besides PA systems driven by massive wattage. He was floored by the experience!

John, your system is inspirational and moves me to do some work on my own. On a constructive note, have you tried deadening the handle on the unit with a liberal application of industrial Duck Tape applied length-wise and then wrapped diagonally for strengthening? I have also found a slight tendency for the cassette tape/CD door to vibrate at the same frequency as the handle, thereby obscuring some of the detail. Duck tape can work some more magic here as well. The same handle mod results, however, can be accomplished by hanging said unit with Twisty-Twine (part # 12002129A from Lowes) from two stock "plant hooks" placed level in studs. I have found a toilet paper roll cut in thirds to provide good backing if filled with sand and covered with Liquid Nails.

Of course, this is opinion and not meant as fact. Results in other applications might be different. Also, Kudos on the wire upgrade! ROMEX can also work wonders when used in tightly twisted pairs with ground shield and filters (also can be used in place of Twisty-Twine if needed).

GOOD LUCK! And remember, LIQUID NAILS NEVER FAILS!

kh

Phono Linn LP-12 Vahalla / Linn Basic Plus / Sumiko Blue Point

CD Player Rega Planet

Preamp Cary Audio SLP-70 w/Phono Modified

Amplifier Welborne Labs 2A3 Moondog Monoblocks

Cable DIYCable Superlative / Twisted Cross Connect

Speaker 1977 Klipsch Cornwall I w/Alnico & Type B Crossover

system one online / alternate components / Asylum Listing f>s>

This message has been edited by mobile homeless on 02-03-2002 at 12:15 PM

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Colin---There are still 4638s left on the JBL tent sale, while I've never heard them I presume they are good. The 4560 is a real good cabinet with the right woofer, I've heard them sound good in home situations with Altec 515Bs and with JBL 2505s. A little bass shy but bassier than the Altec 825 (VOT) cabinet IME.

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WOW! Are those drivers of higher quality than the drivers Klipsch uses? (Just kidding.) One thought, If these were mine, I would make a walnut frame and grill cloth to cover the mouth of the large horn - to increase esthetics and the wife/decor acceptance factor (removable, of course, to show off the horn).

Andy

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