newbie la scala/k-horn project

[JohnA]

I missed the nailing part. That Sucks!

John

[djk]

"These La Scala cabinets, black "utility" finish, have bottoms that are nailed in from all 4 sides." Tip the speaker over on it's side and look.It's not made the way you think it is.

[mungkiman]

I have had these La Scalas on their sides and upside down.

I'm positive that the sides (3, not 4) are nailed into the bottom plate. I'm also positive that this is original factory construction for these utility cabinets. I could cut out the bottom plates, ruining them, and re-assemble with new painted wood, but I don't want to.

I will follow E-bay, but may buy new from Klipsch. Just thought I would try the forum first.

[JohnA]

Mungkiman,

Can you post pictures? I can scan and post photos if you want. La Scalas ARE nailed and glued together, but there is a woofer access plate on the bottom that is held on with 12 screws. It looks like a riser to some. Are they black lacquer, or covered in black wrinkled vinyl? What is the model name, LS-BR, LS-BL, LSI-xx? If so, the access plate is the bottom plate. No cutting required. I've never seen the bottom of an LSI, but *Klipsch* would never have made a speaker that couldn't be serviced.

John

[HDBRbuilder]

As a former employee of K&A from 1976 to 1983...I feel some clarification for this project is in order.

First, the bottom of La Scala loudspeakers (at least when i worked there) was two thicknesses of birch core 3/4" plywood thick...the bottom piece being attached with SCREWS to the upper piece. This was done so that the bottom piece could be removed easily in order to access the 12 inch woofer installed in the folded horn section...when it is removed it will be obvious to you.

Second, the Klipshorn was fired by a 15 inch woofer, NOT by the 12 inch woofer the LaScala utilized, although the same 15" woofer used in the Cornwalls of that time were used in the Klipshorns, and the same 12 inch woofer used in the LaScala, was used in the BelleKlipsch(of course), and in the Heresy. These woofers were manufactured by Eminence Speaker Company to Klipsch specs.

Third, the midrange HORNS of the Klipshorn are considerably larger than those of the La Scala, even though the DRIVERS used were the same on either horn. These midrange DRIVERS were manufactured by CETEC to Klipsch specs.

Fourth, the access door to the Klipwshorn for the woofer is on the side of the folded horn and is a screwed-on weather-stripped "door" panel...removing this panel allows access to the 15 inch woofer inside the folded horn enclosure.

Fifth, the same tweeter was utilized for the Heresy, Cornwall, LaScala, BelleKlipsch, and Klipschorn, and was a cobalt magnet driven Electrovoice model.

Sixth, the Klipschorn woofer FRONTS were made of lumber cored veneered 3/4" furniture plywood for all but the birch models, which used birch core 3/4" cabinet grade plywood. Wherever 3/4" plywood was found in the Klipschorn, it was birch core cabinet grade plywood....but any 1/2" plywood used was baltic birch(which isn't actually 1/2", but sized close to it)

Now we come to the crossover network....and for that you will have to find out on your own...many changes were made over the years. Hope this was some help...by the way...for almost 7 years I built virtually all the birch heresy's, the vast majority of ALL the cornwalls, and quite a few of the MCM1900 theater/concert systems.

[WMcD]

Intersting. Naturally there is no arguing with first hand experience.

Does this mean that the LaScala and Belle had something other than the K-33 woofer. Such would be contrary to spec sheets.

It would also mean the LaScala had something other than the K-400/401 midrange horn.

The Belle has a smaller midrange horn in order to fit the 18 inch depth.

Gil

[mungkiman]

John,

The La Scalas are black lacquer. There is no model name listed on the stickers:

Type K-447

Serial 1L 885/6

There is definitely not an access panel on the bottom. There is, however, what might be an access panel inside! Below the K400 horn is a 13"X17" panel screwed to the top of the bass chamber. The base of the AA network is then screwed onto the panel.

Even after removing the midrange horn, visibility would be extremely limited. Still, I greatly appreciate you insisting that Klipsch would never sell a product that couldn't be serviced. That statement got me to look more closely, and finally inside. I had dismissed this panel earlier, thinking IT was the base of the networks. Not so.

Well now it seems that I may be able to switch all components from the La Scalas into the K-horn cabinets, and back to the original cabinets if I choose. The "blind" work aspect may be tedious, and I hope I don't damage anything by accident.

Thanks again for your help. I will post results when I have the time to start tinkering. I do not have a digital camera or scanner, but I appreciate your offer to scan photos for me. If you or anyone else would like to see pictures of these access panels (or cabinets) I would be happy to send you a photo.

[Tom Mobley]

OK, this raises several questions from me on my Heresy-->La Scala upgrade project. I have multiple references that La Scala's used the same components as a Khorn if they were the same year. I'm back from vacation, ready to order the 15" woofers from Klipsch, and I see this credible looking post from a person who worked at Klipsch building speakers, clearly states that "Klipshorn was fired by a 15 inch woofer, NOT by the 12 inch woofer the LaScala utilized, although the same 15" woofer used in the Cornwalls of that time were used in the Klipshorns, and the same 12 inch woofer used in the LaScala, was used in the BelleKlipsch(of course), and in the Heresy." Seems to be a fairly hefty contradiction here? Anybody had a LS apart recently, confirm the size of the woofer? I don't want to spend the bucks for a pair of 15" woofers if I don't have to. I notice the woofer slot in the LS plans posted here have a measurement of about 13.2 inches, which would be about the right size for a 15" woofer, substantially too large for a 12". Comments?

Also, my Heresy's which I bought new in mid-1978 if memory serves, never repaired or even disassembled, have a squawker labled "K-55V 9/23/77", is this identical to a LS squawker or is there a different horn assembled to the driver? I've noticed in some of the KH pictures I've seen posted that the horn seems to be quite long looking. Too long to fit in a Heresy, or maybe even a LS.

Expiring minds want to know.... Who wants to be the hero that straightens all this stuff out?

Tom

[John Warren]

the 3x13" baffle board slot is a consequence of the k33e woofer. decreasing the slot area increases the shunt capacitance at the throat making the slot/throat combination more effect as a low pass filter. if a "regular" woofer is used the 6x13" slot is needed.

the slot attenuates the upper end output to make a low cost woofer sound like its putting out bass.

[Q-Man]

HDBRbuilder must be mistaken. The LaScala never used a 12" woofer.

Also if you don't have the bottom screw on access panel then they arn't Klipsch built.

Q.

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Q-Man

[hetmann]

I got all the drivers from a set of LaScalas for my Khorn project. The woofers are K-33, 15 inch and the squawker horns are huge. You would not be able to get bigger ones into the Khorn cabinet. I'm pretty sure this set is identical to the khorn driver set.

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Klipschorns and Moondogs

This message has been edited by hetmann on 04-14-2002 at 09:49 AM

[Tom Mobley]

So, apparently, the LS used a 15" woofer as reported earlier. Is there consensus on this?

Now on the squawker, does this all boil down to: I have the right driver but the Heresy used a shorter horn to fit in the cabinet? Is the longer horn available? Is this what I see referred to as the K-400 in other posts on this board? Would I be able to hear any difference between the two horns on the same driver in my soon-to-be-homebuilt LS's? Is it difficult to change out the horns if I can find the right ones?

Full of questions, huh?

Tom

This message has been edited by Tom Mobley on 04-14-2002 at 01:15 PM

[mungkiman]

Q-man,

If these La Scalas (with the access panel inside) weren't Klipsch built, I would be quite surprised. The cabinets are stamped with the serial numbers in addition to the stickers. They were inspected by Iris Powell, and tested by NW Bradford.

Anybody else out there with '73 La Scalas (or an old enough brochure) that can help me figure this out? Thanks.

Serial# 1L885/6

[JohnA]

Munghkiman,

You're going to have to post pictures. Do your La Scalas have an open top like the attached?

All 4 of my La Scalas have 15" K-33-E woofers, even though 2 have square magnets and 2 have round magnets. One pair is mismatched and was made in 1981/1982; the other from 1987.

Tom,

The La Scala requires the K-400 or K-401 squawker horn. The bass horn cannot go much higher than 400 Hz. I hope to test one to see how much higher, soon. The K-700 horn in the Heresy is intended for 700 Hz and above, so it is unsuitable for use in a La Scala. It cannot play low enough to match the bass horn. The K-401 is available new from Klipsch. Both sometimes show up on ebay. Most Heresies used the same squawker driver the KH/LS/B/C used from the same year. It unscrews from the horn and will thread onto the K-400/401 horn.

A very early La Scala, perhaps the prototype, used a 12" woofer. It's in the Museum at Hope.

John

This message has been edited by John Albright on 04-15-2002 at 11:46 AM

[HDBRbuilder]

I have read with amusement some of the things posted after my reply...fact is...that the LaScala has flip-flopped between being driven by a 15" or 12" woofer over the years...my statement that it wsas driven by a 12" woofer at the time i worked there stands...one of my friends currently works there and told me that they went back to a 15" woofer in it...what will be will be...LOL!...anyway, the actual driver that pushes the K-horn, LaScala, Cornwall, and Heresy horns was the same one when i worked there...the difference was in the horn sizes, NOT in the driver powering them...and of course the crossover networks utilized. Of course, another thing to ponder is that the LaScala was never designed by PWK, but designed by Gary Gillum with input from PWK in response to a need by Winthrop Rockefeller for a Klipsch speaker that could be used on a flatbed trailer when he stumped the state of Arkansas while running for governor...thus was born the LaScala...and later PWK took the LaScala and redesigned it himself to come up with the Belle Klipsch..named after his late first wife. Nuff said on that subject, except that Gary Gillum got his inspiration for this speaker design from an old RCA theater speaker behind the screen at the old Hope movie theater...this design also resulted in the later inspiration for the MCM1900 folded horn woofer. Although the inspiration came from this old RCA speaker...the design was clearly a new one that resulted in both of these speakers. An interesting aside was the development of the LB-76 model...which basically was half of the LaScala horn turned up on its side, with the heresy midrange horn unit horizontally mounted over it and the tweeter vertically mounted at the end of the side of the midrange horn. This development came about in an attempt to produce a speaker with similar response of the LaScala, but with a smaller size and weight allowing roadies to more easily maneuver it around for stage applications. The LB-76 was also intended to be produced at less cost, since it required fewer materials...but...alas...the complicity of its design actually required it to use many more man-hours in construction, and negated any possibility of its being profitable so the design was scarpped...about 6 pairs were built...and we employees of that era delighted in borrowing them for weekends to the local swimming holes for parties and such....bye the way...the LB stood for "little bastard" because it was so difficult to build...LOL!

[mungkiman]

John,

I will endeavor to post pictures, but that will likely take several days to accomplish. Please be patient. The La Scalas do not have an open top like the picture, so I'm still curious how easily the woofers will be removed.

I have another question for you. In your original response to my project questions, you answered that my La Scala components would be ideal for Klipschorn cabinets. Do I need a different crossover set-up for K-horns than I have for the La Scalas, type "AA"? I know very little about crossovers, but can cut wire and solder. Any thoughts or advice? Thanks.

[HDBRbuilder]

I stand corected...more or less...the BK and the LaScala utilized the K33E woofer for most of the time i was there. In perusing through some old photographs, I saw that and the spec sheets for that era stated that also. I may have been confusing the K33E with the experimental models we built up. In those the Heresy woofer was ustilzed and in a few we used a large aluminum alloy framed 12" woofer, but that was not long before i left the company, and I can not be sure that design was ever adopted. One thing I am sure of though, is that the crossover networks were slightly changed or adjusted sometime around 1979-81, partly due to one of the engineers being a horn pllayer...he felt there needed to be more presence in the midrange...whereas my personal opinion was that they should have left the crossover alone because it sounded worse to my ears...anyway...i dont know whetehre they changed back to the earlier adjustments or not...i have it on good authority that the current lascalas are leaning more heavily toward the bass bottom end nowadays due to the current popularity of rap...but that can easily be adjusted out.

One question i DO have is why take the guts out of good lascalas to install in K-horn cabinets when the guts can be bought for the k-horn cabinets?...just wondered...plus...if i was gonna go to the effort to build a pair of lascalas for the home, and i didnt intend to finish them so that they could be hauled outside for patio parties, then I would go with building Belles instead...they are much more beautiful...but i have to admit...they are a BEAR to build!!!!

[WMcD]

Dear Builder,

Good hear about a fresh stab at recollections. I thought there might be a problem but wanted to be very diplomatic. I make mistakes myself and it causes me some chagrin.

The "runt" LaScala is in the Klipsch museum from the political campaign. It looks like half a LaScala bass unit. I.e. the configuration we know sliced horizontally, and I thought it might have a 12 inch driver. The mid is a K-400. But did Gillium design this? it is fairly old. I think Gillium's name is on the big theater horn designed later. The subject of a patent.

There is U.S. patent on what could be described as half a LaScala but cut vertically. I'd have to look it up. I recall the patent spec called for a K-33. Again from recollection, it used a K-500 but, again, I'll have to look.

Can you comment on the Belle. Some have told us it uses a front firing woofer which would distinguish it from the geometery of the LaScala. I was going to ask Al. K., Belle owner, but didn't have the nerve. If there is a different geometry, it would square with your comments on the challenge of building it.

Thanks again for your input.

Gil

[Tom Mobley]

HDBRbuilder,

Thanks for taking the time to look through your stuff and clear up these details.

The reason I'm building LS's is that they were what I wanted and couldn't afford back in 78 when I bought my HD BR's that you probably built. Nice job, great speakers, BTW.

This is getting more involved, I need to change out the horns on the squawkers. Bummer. I'll price them at Klipsch Monday or Tuesday, anybody got any for sale? I see some on ebay, but they've got the drivers attached and too much money. Anybody got any of those little stands for the back of the squawkers?

Thanks, Tom

[JohnA]

Tom,

Be patient with ebay, a pair will show up after a while. Altec 511Bs could also be used and some say they sound better. I haven't bought any adapters to try them, yet.

Builder,

This LB-76 you mention; is it a narrow (about 18" wide), tall "J" bass horn or "scoop" with a Belle squawker horn and K-77 tweeter? Did it have optional wings to improve bass performance? The patent date for that was 1979. That's why the -76 confuses me. The '79 patent bass horn is the subject of an inquiry of mine. I toying with having a pair made for rear surrounds. I'm guessing it is taller that a La Scala and would be able to "see" over my furniture.

John