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La Scala Industrial upgrade questions


DaleShirk
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I've managed to obtain a long-wanted pair of 1978 Industrial La Scalas. Now to work them over to make them what I want. They have 1 blown woofer, so I'll probably get two new ones. I also have plans to front-mount the tweeter to reduce diffraction, add some bracing to the bass horn, add some damping to the mid horn, Tri-amp and time-align them with a DSP.

I have a few questions I wanted to ask the Klipsch gurus.
1.These speakers have 3/4 inch wide 1/16 inch thick aluminum angles attached to all the exposed edges to prevent damage when they are moved around. They were at one time the main speakers for a local rock band. Are these aluminum angles OEM or were they added later? I'll probably take them off and veneer the cabinets to improve the WAF factor, but I was curious

2.I've seen the bass reflex bottom module mods and I'm considering doing that since I want to raise the Mid/hi to ear level anyway. Since I need a new woofer anyway, I'm looking at possibly selecting a different one that might respond to the reflex box better. I can do the T-S calcs, but I'm curious if anyone else has done something similar. Does anyon know offhand the flare rate of the bass horn? I can measure and calculate it if needed.

3. I've seen numerous mid-horn replacements, but I prefer to stay more stock at the moment. I have this vague recallection of someone adding damping to the mid horn to reduce resonances. Any guidance there?

4. I want to front-mount the tweeter. Any reason why I can't mount the tweeter from the front then attach the driver from behind?

5. Has anyone time-aligned these? I'm curious as to the effect on the sound. I'm wondering if part of "the sound" is highs ahead of mids, which are ahead of the lows. When I do eventually set them up, I'm going to do a preset each way, one as close to original as the physical modifications allow and one as well tuned as possible. I'm really looking forward to this project.

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1.These speakers have 3/4 inch wide 1/16 inch thick aluminum angles attached to all the exposed edges to prevent damage when they are moved around. They were at one time the main speakers for a local rock band. Are these aluminum angles OEM or were they added later? I'll probably take them off and veneer the cabinets to improve the WAF factor, but I was curious

if they have T shaped corner section, they are probally original. If they are angle cut at each corner, they were probally added. I did see one case of klipsch installed trim that was neither using T shape corners or angle cut....those had but joints. Anyway, if they are original klisch, and you do decided to pull it off for good....I'm in the market for some. PM me if you want to sell it.

2.I've seen the bass reflex bottom module mods and I'm considering doing that since I want to raise the Mid/hi to ear level anyway. Since I need a new woofer anyway, I'm looking at possibly selecting a different one that might respond to the reflex box better. I can do the T-S calcs, but I'm curious if anyone else has done something similar. Does anyon know offhand the flare rate of the bass horn? I can measure and calculate it if needed.

if your lascala have sealed back sections for the horn.crossover area, you could cut out the top of the dog house and cut ports into the section covers and gain the same advantages with out having to add more height to your lascalas. Woofers that work for the lascala's in my experience are the k-33, k-43, k-44, and k-45 (4 ohm version).

3. I've seen numerous mid-horn replacements, but I prefer to stay more stock at the moment. I have this vague recallection of someone adding damping to the mid horn to reduce resonances. Any guidance there?

there are 4 types of k-400 horns. An early type that is very poor cast quality and has to cast notches about a foot from the driver end...this one does not ring at all; a longer production run k-400 which has better casting and no notches....this one will ring if not properly mounted to the motorboard and secured in the rear with a bracket and bolt; a composite plastic version k-401 which does not ring; and a clone horn made by speaker lab called the HD-350 which has excellent casting and does not ring. My opion is a properly mounted mid horn does not need dampening material/

4. I want to front-mount the tweeter. Any reason why I can't mount the tweeter from the front then attach the driver from behind?

You can do it...but not sure if it's worth the trouble...you need to cut the hole larger and best bet would be to obtain some Z brackets.

5. Has anyone time-aligned these? I'm curious as to the effect on the sound. I'm wondering if part of "the sound" is highs ahead of mids, which are ahead of the lows. When I do eventually set them up, I'm going to do a preset each way, one as close to original as the physical modifications allow and one as well tuned as possible. I'm really looking forward to this project.

there are a few threads on this.....you can do a search for threads...time aligning and WAF do not go hand in hand.

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Thanks for the replies so far. The edging is mitered on the corners and not glued, so I think it was added. Also I later found a hardware store sticker on one piece, so I guess that's that. The previous owner thought he had put the edging on, and I thought is was a factory option. I guess that's where he got the idea.

They have no rear cover over the mid/hi and have a definitely homemade 1/4" jack installation. Perhaps these were ordered as plain unfinished install speakers. What were the available options in 1978? Any old catalogs online?

I'm looking at doing time aligning digitally with DSP, so the only extra WAF problem may be a few extra rack spaces. What I currently plan to use, mainly because I have them, is a McIntosh MC2150 for lows, A Urei 6150 for mids and a Stewart PA-50 for highs, all driven by a Rane RPM26z DSP and a Marantz AV9000 preamp. You probably figured out by now, I'm an pro sound contractor. I'll be dialing these in with a TEF analyzer.[8-|]

Dale Shirk

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The single cabinet LSI's has closed in backs with cast Jack Plates. What you have is probably a reagular set of La Scala's that someone has modified. The factory cast trim was glued and screwed to the edges with cast corner piecesThe trim you have was definately added. Take the bottom hatch cover off and see what drivers you have in there. I take it the tags are not on the speakers. The cast jack plates would have had the serial numbers printed or stamped to the right of the banana plugs.

How did you determine that they were 1978's...?

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I'm looking at doing time aligning digitally with DSP

To what degree do you want to really 'improve' the sound?

Do you want to add the equivilant of some new spark plugs & high octane gas to your car or, do you want to swap engines and make a dramatic shift upward?

(note I did not say inexpensive, but I don't know your budget)

Do a search on 'Jubescala' and read about the huge K402 or the smaller brother, K510.

Both will work, the 510 could fit INSIDE the top of the LaScala which is what I'm planning on doing with my center channel. The 402 is huge but the better horn (maybe you won't hear any difference, I think they're similar when on axis)

Just food for thought. The horns are both Klipsch products and all the engineering has been done so it's literally, plug & play. Order horns, the 402 comes with it's own stand, set it on top of your speaker, wire it up to your amp and program the dsp paramaters...

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How did you determine that they were 1978's...?

There is a paper tag on the back, but it is unreadable. Someone, probably the original purchaser, hammer stamped the following on the plywood edge of the back just below the crossover

14S555 on one and 14S556 on the other. Since these seem to correspond with the serial number format, and 1978 is in the ballpark of when I think these were new, I made the fantastic leap of logic from there. They also have the name of the band stamped in "Daybreak"

The dead woofer I removed has a square magnet and the numbers 6930009 and 137 7210 and 8 Ohms. I think the polepiece shifted, since the cone is pushed forward and blocked. The VC is open.

I'm gonna try attach a pict.

post-53467-13819666044006_thumb.jpg

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To what degree do you want to really 'improve' the sound?

This is probably as much a science project as it is to obtain speakers for my listening room. I hope to be measuring and documenting as I go. Someone mentioned that changing from rear mount to front mount on the tweeter won't make much difference. That's probably the first and easiest thing I can measure. I've been studying up on diffraction, and everything about that rear mount looks bad from a diffraction perspective.

I've heard these speakers in concert as an audience member and mixed music on them myself a few yarr..mrmmr..mrmr..OK, Decades ago. They had the characeristic clarity y'all here are familiar with, inspite of some obvious problems. I'd like to identify and repair those problems. I'm asking about stuff here to get a better understanding of their history and a better lay of the land before I start.

BTW, it's not at all clear if this is the best forum branch for this discussion. If not please direct me.

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How did you determine that they were 1978's...?

There is a paper tag on the back, but it is unreadable. Someone, probably the original purchaser, hammer stamped the following on the plywood edge of the back just below the crossover

14S555 on one and 14S556 on the other. Since these seem to correspond with the serial number format, and 1978 is in the ballpark of when I think these were new, I made the fantastic leap of logic from there. They also have the name of the band stamped in "Daybreak"

The dead woofer I removed has a square magnet and the numbers 6930009 and 137 7210 and 8 Ohms. I think the polepiece shifted, since the cone is pushed forward and blocked. The VC is open.

I'm gonna try attach a pict.

The numbers stamped into the edges are from the factory. Original Heresy speakers also had the numbers stamped the same way.

That woofer looks like it has been wet, and will surely need to be replaced. La Scalas use a 4 ohm woofer, so this is probably not a Klipsch part, but one someone has substituted. You can get the real deal from Klipsch parts or other high quality ones from Bob Crites. Bob also has a cast frame woofer, but it won't fit the LS cabinet without trimming off some of the frame.

Bruce

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