Question on "pro" LaScalas

[Coytee]

I don't know if they're "pro" or not based on any numbers I saw, so I'll describe them visually.

First... they are standard shaped LaScalas (single piece). Second, the opening of them in the back, has a piece that encloses it and on this board, is another "cup" with terminals on it. This terminal cup is then wired to the actual crossover inside the cabinet. The cabinet has handles on the sides and (possibly added by someone else) some kind of protective piece on the edge of the 'horn nose'. There is NO corner protection on any of the corners (although it might have been removed?)

The serial number does NOT equate to anything I've seen and I can't figure it out, per the serial number code (it's just a list of numbers, maybe 9 digits long)

I think the crossover was an AL3 if I recall. It had a little white rectangular piece (I think perhaps a resistor?) that was maybe 3/8 inch square by 2 inches long? This item had some white "fluff" on it as though it was scaling off.

I swapped out one of Al K's ES networks into this box and the entire speaker sounded better & more clear than the other one in the room.

If indeed, my descriptions are that of a 'pro' style LaScala... would it likely have a K33 inside it? If that was some kind of 'scale' on the resistor, would that indicate some kind of issues with age ?

[Guest " "]

I have a set of LaScala's that say "Professionals" on the label. They are basically home version K-33/k-55-v/AA xover/Single piece/enclosed back LaScala's with the black fiberglass coating and metal trim all around.

However, there are apparently two other non-home versions. One is an industrial version and is labled as such. These have stamped frame k-43's, more comonly a k-55-M, and more commonly AL xovers. These come in single piece or two piece. Black fiberglass finish, black painted, metal trimmed, and even unfinished.

The other version is a theather version. This one has a K-43-KP cast frame woofer and stackable corner guards instead of the flush aluminum corner guards.

[G.Kennedy]

Mine are ... Split, natural wood finish, K77M, K55V, K43(stamped), AA crossover, from 1981

[rjrbass]

My 1993 La Scalas have the AL-3 crossover network, and the 9 digit serial number, on a "different" Klipsch label. The label is not the commonly seen label, but Klipsch infomed me that it was used when my speakers were manufactured.

The 9 digit S/N was used from 1990 - 1997, and the AL-3 crossover was used for part or all of this period.

My speakers are not industrial or professional.

Date Code: DOY Y1Y2 #### Example 123391234

123rd day of 1993

[colterphoto1]

There are two giveaways to 'pro' or Industrial in this instance. One is the presence of a cover over the mid/hi portion of the cabinet with integral jack cup. Unless someone added this later, it's a key to an Industrial. The jack cup probably gives wattage rating for each component, has twin dual banana plugs, possibly for LF and HF separately, and fuse protection. Possibly a 1/4" jack but that was rarely used as it's not a good termination for pro sound.

Another give away is if the woofer hatch door is inset. In the standard versions, the door is surface mounted, providing a 3/4" 'riser' of sorts. On Industrial models it is inset so the base of the cabinet is flush. Important if you're moving them about and stacking them. Usually 3/4 dia x 1 1/4 rubber feet were screwed to the bottoms.

AL3 should have a K55M, which was used on Industrials. The square thingie is a resistor. The AL's were confusing looking networks. The semi-sealed backs should have offered more climate protection to the networks than an open back cabinet. The serial numbers made no sense and we have no records of them. Remember that another company produced Klipsch Industrial for a period of time.

If original, these should be sporting K43 woofies. They are excellent for annoying neighbors.

Handles and other hardware were sometimes put on standard LS models, which would then look industrial, but not technically be.

ROCK OUT Richard!

Michael (you can call me Mr. Industrial)

[Coytee]

Nice tidbits Michael...thanks! I just realized that covered back might just be a sporting place to hide things, like ribs?? Do you think even Master Roy could sniff them out if hiding there?

Aside from that, if these DO in fact have the K43, then as I understand the basic facts, the K43 gives up some bottom end extension but is a bit more robust and perhaps capable of more SPL's. The K33, being a bit lighter driver, might then actually dig deeper but not able to withstand some volume abuse. Fair so far?

So, in HOME use, the K33 would tend to be the driver of choice because it will dig deeper yet, still provide adequate spl for home use. I know that I can personally attest that MY LaScalas lived through 4 years of college doing what many college kids do, especially when hired out to play the music at frat houses.

I was always amazed at the abuse I put my poor drivers through and have never EVER burned one of them out. These are the same parts that were installed in 1979. My EV's on the other hand (using ST-350's) have burned probably 4 tweets out.

[Coytee]

My 1993 La Scalas have the AL-3 crossover network, and the 9 digit serial number, on a "different" Klipsch label. The label is not the commonly seen label, but Klipsch infomed me that it was used when my speakers were manufactured.

The 9 digit S/N was used from 1990 - 1997, and the AL-3 crossover was used for part or all of this period.

My speakers are not industrial or professional.

Date Code: DOY Y1Y2 #### Example 123391234

123rd day of 1993

Richard, that sounds like you have something identical to what I saw. I didn't write down the number code as you show it but I'll point that out. You're right about the tag too... on these, it was more like a 3/8" x 2" strip of tape with the numbers on it and NOT like the 4x4 sticker my LaScalas have. The little strip of paper with the serial number was attached to the input cup.

Anyone have any thoughts as to what I'm calling "scale" on the resistor?? I don't know how to describe it but I'll try.

It looks like a little resistor. I have one downstairs that is 8 ohm but this one is much smaller. It's white, retangular and has leads on each end of it. The scale I'm talking about ....gads, I just can't figure out how to describe it... it's like white powder but is stuck to the part. If you scratch at the powder part, it will scrap off. I tried to "wipe" some off with my finger to show Chris, but it just fell off my finger and created a little dust pile at the bottom.

It was almost like "rust" although being ceramic (I presume) it's clearly not 'rusting'. I just found it strange that what I believe to be a ceramic piece would be flakey like this.

[G.Kennedy]

The resistors sounds like ... a rectangular Sand Cast wire wound resistor. Maybe ... if it has gone through a million heat cycles, it is coming apart .... sounds just like oxidation on the outside though. If you handy with a soldering iron and an ohm meter ... pop it out and test it .... you should be able to find the schmatic with the value for reference here on the site.

Or just replace it .... its probably a $1 part and will give you piece of mind. You need to match Ohm rating and wattage rating

The little 3/8 x 2" tag you mention ... on mine ... and others I have seen .... Is where the final inspectors have signed off on the speaker ... it has signatures on there.

You can see it here:

[colterphoto1]

Richard, you are spot on with your K33/K43 analysis.

Do you need an outlet for those K43's so you can get the K33's?

[Guest " "]

mine have a covered xover, cup type connectors, watt range per drivers as you indicate, inset woofer cover and they are labeled Professionals. They aslo have the black fiberglass as well as the aluminum trim. K-33 woofers/AA xovers/k-55-v mids.

[Coytee]

Do you need an outlet for those K43's so you can get the K33's?

I doubt it, at least at this junction. The speakers belong to a friend in Oak Ridge. I happen to have an extra K33 that is going to go into my empty LaScala box once I get around to it. I might drag it over to his place & swap a single driver out so he can see what it sounds like. Once he hears it (single speaker being changed) I'll let him decide what he does/doesn't like.

Who knows... maybe if he doesn't like it...I'll put the K43 back in, but if he does like it...then an interesting situation arises...

Do I put the K43 back in and let him listen to balanced woofers for "X" days it takes to have new ones arrive and then re-do everything OR, do I just keep the K33 in there and consider that speaker "done", letting him listen to possibly off balance bass for several days and when the two arrive, just put the other one in and swap out the 2nd one as "mine"

(Chris...if you're reading this, I already presume to guess we'll put the speaker back into balanced configuration & redo it, I'm just suggesting leaving it unbalanced to annoy you [])

[Coytee]

K-33 woofers

Hmm...the plot thickens.....[:^)]

[G.Kennedy]

............. they are labeled Professionals. They aslo have the black fiberglass as well as the aluminum trim. K-33 woofers/...........

That just does not fit the pattern ........should be K43's..... have your woof's been replaced ... I say crack them open again and take a look ...... (although I am sure you have)