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Help Teens Rebuild LaScala Speakers


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Very cool project!  When done, you can use the 9090 and both pair and have a great block party.  La Scalas don't have any low bass response, so if you want to have an outside party, you should rent/borrow some pro subwoofers.

 

The grey paint makes me think they were used for a theater or something like that. 

 

Be very careful with a belt sander (I wouldn't use one).  They are made from quality birch plywood, but the top layer is thin and easily sanded off. 

 

 

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Are two of the serial numbers listed the same? I cleaned my glasses but it seems that way in your post.

Also let me add that you're not really measuring for a short circuit in the voice coil. Rather, the long spool of wire in the voice coil has a d.c. resistance of about 4.0 ohms. If it is melted in a spot from misuse it will have a "infinite" or very high resistance. This is usually whatever your meter set to ohms ( ohms = omega = Ω)

 shows when you don't touch the leads together. Sometimes this is "OL" on the display.

Most often, if you see 4.0 ohms plus or minus 0.3 ohms, you've got a good woofer. If infinite resistance, it is blown. It is rare that anything else happens. (Granted, sometimes the voice coil gets hot enough to warp and jams in the gap.)

The mid and the tweeter can be tested the same way. They will probably have a resistance of about 10 to 12 ohm and infinite ohms indicates a burned out voice coil. You don't have to worry about the 0.1 ohms in the leads, in my experience, though it can't hurt and the young adults will learn something.

When you use the ohm meter on a good unit, you may hear some scratching sound from the unit. This is a good sign. The meter puts a small amount of current through the leads and attached device and this causes the noise.

WMcD
 

Edited by WMcD
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There is an article by Klipsch regarding the LaScala in an earlier post of mine.

 

https://community.klipsch.com/index.php?/topic/53241-article-aes-preprint-re-lascala-by-pwk/?hl=%2Blascala+%2Baes+%2Bpreprint

 

People usually want to know why the orientation of the dog house is as shown.  I don't know.  When horizontal, the hatch(es) must be on the side(s).  Two hatches would give easy access to the screws mounting the woofer.  But the wires to the cross over would have a complicated path.

 

OTOH, one hatch on the bottom is more elegant.

 

WMcD

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Cool project. Get them as square as you can. 80-120 on a D/A. Keep it flat. Easy on the front. I would laminate 1/4" mdf on the 2 sides, and top and bottom. 1/8" notch trowel to lay up the glue. Lay up on flat surface. Use the weight of the cabinet to clamp. Wood glue only. One side per day. Flush trim router bit and move on to the other side. Bodywork and sand. Much faster, flatter, and precise than trying to clean up the original cabinet. Plus you will have 1" thick cabinets. Solid. 

 

I like the idea of black on the bass bin area. That's a very hard part to veneer. I have a pair in the wings that I'm going to do the 1/4" overlay, and cut the tops off. Separate bass bin and top. 1" all the way around. Totally square and just knock the edges off with some 180. Semi-gloss on the mouth of the bass bin, DuraTex all of the outside. 

 

Here's a link that shows what I did on a pair.  https://community.klipsch.com/index.php?/topic/113839-la-scala-1/

 

My best advice is to make the point of the bass bin look as good as possible. That's where everyone looks and checks your work. 

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Hey Folks,

update onpost-63196-0-34440000-1465856988_thumb.jpost-63196-0-06840000-1465857258_thumb.j the project, first crossover AA is out...

request sent to Crites for repair options.

Label protectors installed...

Purchased the long screwdriver to start on the horns.

Checking out the veneer suppliers in the area.

 

Photos attached.

 

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Hello Folks,

well we have our first speaker disassembled. Tested the drivers with a multi-meter: woofer 3.7 ohms (3.7-4.3 normal), mid 11.0 ohms (10-12 normal), tweeter 6.4 ohms (10-12 normal) looks like this one needs work. Is this something we can fix ourselves with a replacement part?

 

Also, the mid horn has some surface scale (aluminum rust?). We have access to a bead blaster. Would there be a problem if we cleaned it down to bare metal before repainting?

 

When we removed the bottom, a black gooey ribbon gasket was sticking to both surfaces. When we replace the bottom, what is the material used for this purpose. Looks like it was originally attached with small staples. 

 

Emailed Bob Crites about the crossovers and we're leaning towards going with new replacements (we can afford the luxury as we're selling a pair to cover costs).

 

Looked at a lot of refinished LaScalas and the kids like a lighter wood (maybe white oak with Danish oil) and a black grill over the upper section...we'll frame the front edges (and below the grill) with 1/2" x 3/4" stripes of solid oak. The lower cabinet interior, back and upper horn enclosure in a satin black. 

 

Thanks again,

-Mark

 

note to WMcD: the font in my post does have the serial numbers 6 & 8 looking very similar

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Also, the mid horn has some surface scale (aluminum rust?). We have access to a bead blaster. Would there be a problem if we cleaned it down to bare metal before repainting?

 

No issues. This would be a good time to see how round and smooth the throat (small end) of the opening is, and to file smooth if necessary.

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Thanks for the tweeter / Ohm clarification mungkiman...

One question: when we pulled out the woofer, the rubber gasket (where it meets the cabinet) is pretty hard and dry.

Is this something we should address...replace/rejuvenate?

Well, off to the hardwood veneer store today. Looks like folks have had good success with paper backed products and heat activated glue.

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Woofer gasket - $ wise - Go to local Big Box Hardware, or any Old School Hardware store and get something like - 

 

https://www.amazon.com/M-D-Building-Products-6577-Sponge/dp/B000HE5Z9U/ref=sr_1_8?ie=UTF8&qid=1466195112&sr=8-8&keywords=MD+weatherstrip

 

Generally --  https://www.google.com/search?q=md+high+density+foam+tape+weatherstrip&rlz=1C1AVNC_enUS590US647&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjJ-Oul9q_NAhUJWj4KHU5jB4sQ_AUICSgC&biw=1164&bih=848

 

Like $5 for both Woofers.

 

It comes in varying firmnesses.

 

I , myself, would choose the  medium to softish stuff, not the super firm.

 

I would think this would be prudent for the mid horn also ( not for "sealing" of course, but for like vibration isolation reasons.)

 

My opinion, others chime in. 

 

Excuse me if I'm talking down to you, nobody knows about everything.

Lars

Edited by Karsoncookie
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Back from the hardwood veneer store (MacBeath in San Francisco) and they have some really beautiful wood... very tempting... but first we'll have to see how we do on the sale of the first pair.

 

Looking at the drivers, I think we should take apart the tweeter to sand off the rust and repaint. Anything we need to be aware of in this process?

 

Should we be concerned about the mildew on the woofer?

 

-Mark

 

 

 

 

 

 

post-63196-0-17120000-1466259898_thumb.j

Edited by mark heija
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Back from the hardwood veneer store (MacBeath in San Francisco) and they have some really beautiful wood... very tempting... but first we'll have to see how we do on the sale of the first pair.

 

Looking at the drivers, I think we should take apart the tweeter to sand off the rust and repaint. Anything we need to be aware of in this process?

 

Should we be concerned about the mildew on the woofer?

 

-Mark

 

I would have the woofers reconed, or replaced, I don't know who the best speaker shop is in SF, but there is one.

 

The musicians that play live music blow their gear up all the time, so the musicians know who the best repair shops are. Or go into any place that has lots of live music and start asking around, you can also search the local yellow pages on line. There are several places you can ship them to for the recone Parts Express and Simply Speakers Tampa, and others.

 

Recone or diagphragms price list

http://www.simplyspeakers.com/klipsch-speaker-repair.html

 

I don't think Crites Sells recone, kits, but he does sell replacement woofers that would be all new. The existing ones can be sold on e-bay and someone else will recone them. Someone probably knows who the OEM was for the Woofers, ElectroVoice maybe and the kit number to order if you go recone. You can post this as a separate topic in Tech and someone will respond with the kit info.

 

If you are talking about the gasket between the woofer metal frame and the wood cabinet, that is part of the recone kit. The gasket between the wooden parts on the bottom of the speaker called the dog house for obvious reasons, can be different materials like weather strip.

 

The mid range drivers are the heart and soul of the LaScals so tread lightly if you are going to paint them or bead blast them etc, there is a rubber gasket to contend with and dust and debris concerns, They too can be sent out to Crites for new diaphragms and gaskets if you so desire, I would ask him about painting if you are sending them to him, pretty sure the top cover can be removed and painted, very carefully don't touch the diaphragms.

 

Judging by the mold on the speakers, I would give the inside of the speakers a careful look with a flashlight once the woofers are out.

 

Crites sells replacement tweeters with the lens two models, disassembly of the stock tweeters, bead blasting and painting may be more then you think, Check out K-77 Electrovoice tweeter rebuilds on Youtube. If you get new tweeters, the old ones can be sold on e-bay.

 

IMHO negotiate new tweeters, new woofers and new diaphragms for the mid range with Crites and ship him the mid range drivers after you repaint them for service and test. You will have new speakers in a better than new cabinet when you are done. The more expensive tweeters Crites sells are the better ones IMHO, ask others.

 

The large metal mid range horns interior must be inspected by looking for any casting defects visual, and then feeling with your hands for regular shape and smoothness particularity at the thin end the driver bolts to, if you have calipers measure the diameter, one LaScalas owner who owns a machine shop actually bored out his horns to bring them to spec.. If they need work, a good machine shop (performance engines etc) when they are done being amused will probably quote a fair price. Crites sells the replacement gaskets, looks like a hose washer. If they are machined, paint them sooner.

 

I like the AA crossovers and would build the system around them or the Crites replacement, the more on the mid the better.

 

Your old tweeters, woofers, crossovers can be sold on e=bay since they all test good, show the photo with the test meter connected so the numbers are readable. Describe and show any defects.

 

Agree, applying the veneer is the final step after all of the hard work is done.

Edited by Bubo
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Back from the hardwood veneer store (MacBeath in San Francisco) and they have some really beautiful wood... very tempting... but first we'll have to see how we do on the sale of the first pair.

 

Looking at the drivers, I think we should take apart the tweeter to sand off the rust and repaint. Anything we need to be aware of in this process?

 

Should we be concerned about the mildew on the woofer?

 

-Mark

Re-cone kits for the K-33's are long gone. Have you tried spraying vinegar on the mold to see if that kills it off? If the mold hasn't eaten through the cones or weakened them, this may be enough. I have had some that were eaten clear through with this mold, so it's a crap shoot. The Eminence Kappa C is a great replacement woofer, and Crites also sells replacements for the K-33. 

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Mold is effectively dead with no sufficient moisture to survive.

 

As long as the drivers are kept in regulated  (normal interior) humidity from now on, the mold spots are no problem, other than aesthetically.

 

"Rust" on tweeter horns - Are those steel? I thought some alloy. Either way, remove from driver, scotchbrite or whatever, wash with  like Dawn dishsoap scrub w brush well and rinse well.

 

When totally dry,  repeat process w mineral spirits.and repaint, like anything else.

 

There may be cautions to observe in the driver/ horn seperation.

 

I'll leave that to others.

 

Outside that, pretty darn basic.           Lars

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