at the risk of being redundant...

[Tom Mobley]

Hi, All

Nice board. I'm an moderator on a another UBB board, this one looks good to me.

Here's the deal: I have a set of Heresy's that I bought new in 1978, they've never been abused and sound just like they did then. Can't claim that for my ears, tho'.

I really wanted La Scala's then, couldn't pop for the cash. Now, after spending a couple months lurking your board, I'm sniffing around the edges of building a set with most of my components. Here's what I have, looked the other night, this is the first time the back has been off either of these.

I found:

woofer K-22

Squawker K-55V 9/23/77

Tweeter K-77

Crossover Type E

two big silver Caps 2uf

T2A

woofer out of phase with squawker and tweeter?

I've looked around for plans, haven't found anything good. Anybody got a pointer to some? On ebay there's all kinds of stuff, I'm not very confident in it.

I take it I would need a 15" woofer, I see all these dozens of variations on them, can somebody point me to a simple way to get what I need?

Will my crossover work for this?

And the big question, is this worth doing? I need all the help I can get with music, my ears are damaged by years of shooting and racing open exhaust cars, but I can't usually crank the volume way up to compensate.

Any and all reponses will be appreciated, even if it's along the line of "why would you want to do something as dumb as that?"

Tom

[j-malotky]

Tom

One thing for sure - you can get LaScalla's LOUD!!!

Presonally I would look for a pair on Ebay hopefully close enought to pick them up and not pay shipping. There are probably 2-3 sets per week and something will show up close to you. Or a pair listed locally, ask arround or on this board...

The LaScalla uses K-33 15" woofers, not the K-22 or K-24 12". The K-55-V is a mid horn driver it can be used, BUT, if it is from a Heresy it is a k700 mid horn. The LaScalla uses the K400 or K401 horn. MUCH LARGER.

I know for a fact that "Big D" has a k-400 horn available for sale.

The k-77 tweeters are the same and can be used

Can't comment on Crossovers. but most likely the Heresy Xover will not work properly.

Again - If it were me - I would look a while for a set.

Good luck either way.

JM

[HornEd]

The GOOD NEWS is that studies show most people who build their own speakers like how they sound.

The BAD NEWS is that good speaker design requires a intricate knowledge of cabinetry, volumes, electronics, room acoustics, psychoacoustics, etc... or enough luck to win the lottery! In which case, I suggest that you use the winnings to buy your heart's desire. -HornEd

PS: If that doesn't dissuade you (it didn't me)... then put out some more variables like room size and configuration, audio equipment you will use with it, and what sort of source material you prefer. You are likely to find lots of people on the Forum willing to help you build darn near anything! H.E.

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

Photo update soon! -HornEd

[Klipschguy]

Tom,

You may want to sell your Heresys to defray the cost of La Scalas. Selling your Heresys on ebay will likely fetch about $500. La Scalas on ebay will cost you about $900-$1000 for a nice pair.

Regards,

Andy

[edster00]

Tom,

Welcome to the BB!

"why would you want to do something as dumb as that?"

LOL!

There are LaScala & K-horn plans for sale on ebay frequently. BUT-If you really don't want your Heresy's anymore I would sell them and buy used LaScala's rather than try to build cabinets and use parts from the Heresy's.

Are you looking for a 2 channel set-up or HT or a combo of both? Heresy's would make great surrounds and/or center channel speakers to use with LaScalas.

This message has been edited by edster00 on 04-01-2002 at 07:19 PM

[John Warren]

LaScala plans here

This message has been edited by John Warren on 04-02-2002 at 05:49 PM

[Tom Mobley]

Thanks everybody. Interesting seeing your responses. At least nobody said it was completely dumb. Yeah, I thought about buying a used set, but where's the challenge? Anybody with a fat checkbook can do that, and I don't have a fat checkbook. I like to do stuff myself, often turns out real good.

Thanks, John for the plans. I'll take awhile and look them over. I know a guy who has a real nice carpentry shop, that helps. Also helps that I fixed the engine in his race car a couple times.

Tom

[Tom Mobley]

OK, looked at the plans, not that bad. What I can't figure out is the function of the 4 parts #2 and part #3. Makes it look like the woofer fires through the 3" x 12" slot into a square closed chamber with funny mitered joints. Guess I need to see a picture of a La Scala with the back off.

This drawing is in German, anybody know the ebay name of a quality vendor who has a little more detailed plan, maybe with some step-by-step instructions? I'll need help with the glue and screw part.

Really doesn't look that bad, only a couple pieces have funny angles on the edges, it's do-able.

Any further comments on the bass driver, crossover, anybody got a pic of a La Scala with the back off?

Thabks for taking time to reply,

Tom

[djk]

wê2åÝ-lpB9¥/óòO~_C/þQýû¿÷£n John Warren, what does it take to open your document? It looks like Sanskrit to me.

[John Warren]

djk-

I uploaded the plans (Isophon copy) to the LLC server. the plans were on a Word document.

Tom-

They are in "metric", Schnitt means "view", what else do you need to know? They are high resolution, you can zoom up to C-size and get clear numbers.

Also, why get "screwed" on ebay? I just gave you the same plans the ebay scammers are hooking $50 for.

[JohnA]

If I were going to build my own cabinets, I'd build a "J"-shaped bass horn sometimes called a scoop. Mr. Paul designed one and published it in a paper I have. It would be taller than a La Scala, but I believe it could have a lower cutoff frequency and therefore deeper bass response. You'd use the rest of the La Scala components as is.

John

[Guest BobG]

The slot puts the woofer in compression.

[Tom Mobley]

well, OK, I'm not afraid to look dumb. Here's my question(s):

It looks to me like the woofer mounts facing backward on the inside of part #12. Is either side of the cone open to the atmosphere? Looks like the 12 x 3 slot opens into a square closed box bounded by the 4 #2's, the #12 and the back. Is this right?

Also, the piece labeled #7, does it have a funny shaped hole cut in it, sort of like a home plate shape with the tip cut off?

On a larger view, how is the woofer serviced? Is that what the hole in #7 is for? Take the bottom plate off and go though that hole?

Expiring minds want to know.....

Tom

[WMcD]

This might help.

The magnet end of the woofer is in "the dog house". There is a cut out in the bottom of the dog house for access. It is sealed with a piece of ply.

The other side of the woofer faces back. It fires through the slot. The sound goes left and right at a prism shaped piece (not shown below). The are two expanding ducts, left and right, opening up toward the rear corners. Then there is a turn forward at either rear corner.

Gil

This message has been edited by William F. Gil McDermott on 04-03-2002 at 06:57 PM

[WMcD]

Well, I see my efforts to post an image into the message did not work. Any hints? I tried using the picture icon and was refered to a URL. Maybe that has to an image uploaded and not a local drive?

In any event.

The magnet end of the woofer is in a sealed chamber formed by the doghouse. Make sure it is well sealed and air tight.

Then you have to understand that the "front" of the driver is looking into two ducts which together form the "exponential horn." They are sort of like a megaphone in front of the driver. That is the horn principle but the horn is not a cone. (We know that megaphones work, and for the same reason.)

In horn terminology, the small end near the driver is called the throat, and the big end at the room end is called the mouth.

The "exponential" equation describes how the area of the horn expands as you go from throat to mouth. You see equations using "e" raised to a power. Don't worry about the math because it built into the design.

Odd math aside, it is easy in the LaScala. Every foot (12 inches) of path, the area doubles. The bass unit overall is a cube 2 feet on a side. The metric measurements work out pretty close. Looking at an individual path, it is one foot across the back and two feet to the front.

At the throat just at the other side of the slot (at the center of the back), the total duct area is about 1/2 square foot.

We travel 1 foot to the back corners and the area is 1 square foot (total), and we turn a corner on either side.

Then we come forward toward the front and at the halfway point, an additional foot, the area is 2 square feet.

Then we come to the front in an additional foot, and the mouth area is 4 square feet.

This doubling per unit of path length is what the complicated exponential equation describes.

Gil

[arfz28]

Sorry to have to ask this but I dont know nothing much about the metric scale. How do you convert these numbers to inches. In the fist photo it showes 612 across what is this in inches and how do you convert it. these plans are good but I dont know about the measurements. To bad they arent shown in inches. Can anybody help a metric dummy like me . thanks

[Tom Mobley]

William,

Thanks for your effort, the deal finally sank through the sheer cranial bone density. This looks a lot easier now.

I managed to survive calc I, II, and III, diffeq, all that jazz, I understand the horn deal, I just didn't picture correctly how the pieces of wood were arranged.

On your pic, yes, it must be available on the web somewhere, you can't link to it on your local drive unless you're running a web server and open to the public. Doubt if you're interested in that.

Thanks for taking the time to help. I think I'm gonna do this deal, just need to find the drivers. Any suggestions? If I go to ebay, what exactly do I look for? Is there a vendor where I can just buy them retail?

Thanks for all your help and insights,

Tom

[Tom Mobley]

arfz28,

divide the millimeters by 25.4 to get inches. as I recall, this is exact conversion, not any rounding error there.

ex: 612mm/25.4 = 24.09in, just about 2 feet

not hard at all, if you have inches and want mm, multiply the inches by 25.4, get mm's.

Tom

[WMcD]

Okay, a wireframe drawing of a LaScala is attached.

Now, how do I find it's URL to paste into the text? This might work.

The drawing brings to mind one "fudge" in the design. The second foot of the flare, i.e. from the back to half way to the front, does not quite expand like one would expect; in fact the area is constant. This is the side of the doghouse. But the final flare formed by the roof does go to 4 square feet.

I suspect this is to (1) make construction a bit more easy and (2) to make the flare a bit more hyperbolic. The latter is a long story.

Gil

This message has been edited by William F. Gil McDermott on 04-04-2002 at 11:25 AM

[Tom Mobley]

yeah, that's what I needed all along. this is looking better all the time.

checking ebay I see that there's some 15" drivers listed:

Stephens 103-LX2 15" woofer for Klipschorn

also mentioned is Altec 515b, which looks like it's 16 ohm, is this a big deal? I see the 515b mentioned several places in connection with the Klipschorn, is this what I need?

will my Squawker K-55V, Tweeter K-77, crossover Type E work for this deal? I've got a feeling I'm going to asking Al K for a crossover.

Thanks for all your input, especially the dedicated william F. Gil McDermott, who really went the extra mile to help me.

Tom