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LaScala splitter and throat restrictor plate measurments

22frank

22frank

Active Member
Hi All, I have the Klipsch LaScala loudspeaker and am perplexed at the internal dimensions.
I will share my findings and hopefully others will share their findings.

My LaScala is #3N204 a 1975 y/mfg unit costing $525 including free shipping to my home from Hope, AR.

At that time the restrictive throat was 3 x13 inch for the K33P woofer. The splitter behind that throat was a rather large piece as shown.

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Having my LaScala many years before the Personal Computer I was in Loudspeaker bliss mode.

After my first venture online I saw "factory" inter web dimensions begging to differ.

The splitter : a smaller strip of wood 2 1/4 wide. As the date is 1977 was this an improvement?
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The 3 x 13 inch built in throat restrictor was the same as the Klipschorn and still is. At some date before 1975 this
throat was 6 x 13 inch. My feeling is - when Klipsch lost the EV 15WK motor they went downhill and never could
afford to get back.

How do your motor boards compare from your year of mfg?


EV Georgian.JPGP1010848.JPGP1010276.JPG Sound quality vs Bean counters.
 
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I'm pretty sure that the motorboards have stayed the same throughout, the splitters may have been made smaller for ease of manufacturing and cutting costs. I wouldn't worry too much about it.
 
My 1974 LaScala's have the 13x3 slot. I never measured it but going by your pictures and dimensions, that is what I have.
 
THD+N said:
My 1974 LaScala's have the 13x3 slot. I never measured it but going by your pictures and dimensions, that is what I have.
Click to expand...
My clones also have a 13x3" slot. my diffuser is somewhere between 2-1/4" to 3" wide, with the cuts made at 45º angles. I did refer to the cut sheet that you posted above, among others, when building mine. IIRC, that's not a factory cut sheet, but one that somebody made and shared to assist others in building their own clones. There are several variations floating around that are mostly accurate, but to my understanding, none are official documents.
 
Thanks for sharing your dimensions. ..

My 75 LaScala came with the K33P motor, a 15 inch woofer with the 40 watt 2 inch voice coil. The first thing to go was the K77 alnico tweeter, open voice coil. The 1N3996 zener protection didn't protect. Klipsch replaced this for free under the limited lifetime warranty.

The next to go, the K33P burnt voice coil. Klipsch charged $33 for a exchange. This was a K33E sguare magnet version, again with the 40 watt 2 inch voice coil. It was nothing special, there was no internet/forum back then.

For my LaScala I chose a 5.25 x 13 slot to provide a 1 to 2 compression ratio, similar to the Peavy FH-1 bass bim.

After opening up the motor board I fitted the EV 15B woofer. Much better sound/tone, crossed over at 100 Hz to a subwoofer.


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Many woofers will work in the LaScala horn better than the OE K33 and all of its derivatives. I am currently using Celestion FTR15-3070e's in mine.

I also have them braced as illustrated in your diagram posted above.
 
THD+N said:
Many woofers will work in the LaScala horn better than the OE K33 and all of its derivatives. I am currently using Celestion FTR15-3070e's in mine.

I also have them braced as illustrated in your diagram posted above.
Click to expand...
I'm using JBL 2225 in mine, but I selected them for a somewhat different range than stock, emphasizing low end extension and impact.
Invidiosulus said:
And yes, I also braced my LS.View attachment 3131219

The throat opening in mine is the 13x3 size and the deflector is the smaller size with the pieces cut at a 45° angle.
Click to expand...
I've also braced mine. one thing to regard is that in increasing the size of the restrictor opening, you will likely reduce the sensitivity of the horn and alter the frequency range of the horn loading and transfer point into bass reflex. This, IMHO, is not entirely desirable. While I did significantly re-engineer my clones for increased low-end response, I left the restrictor opening the same to maximize the range of horn loading.
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THD+N said:
Many woofers will work in the LaScala horn better than the OE K33 and all of its derivatives. I am currently using Celestion FTR15-3070e's in mine.

I also have them braced as illustrated in your diagram posted above.
Click to expand...

Thanks for the reply, You are starting to wake me up!! thanks.

Starting with the woofer/motor drive unit. A given driver has a individual sound in a bass reflex cabinet.

Does this carry on in the horn cabinet? No electric bass players play into their - horns??

Anyway Bruce Edgar (rip) hand built many mid bass horns and tried woofer/motors of his time period.

He liked the EV 15B, not the most sensitive, or largest voice coil, or magnet. It was the sound/tone in the room.

That was how I picked my bass/driver. for my 1/2 diy LaScala.
 
As for the throat opening in 15 inch woofer driven mid bass horns. In the Klipsch LaScala it was copied from the Klipschorn bass bin at the inception. The K33 woofer of the day as the driver.

This opening dimension can be tailored for an individual woofer and for the compression ratio wanted.

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22frank said:
Thanks for the reply, You are starting to wake me up!! thanks.

Starting with the woofer/motor drive unit. A given driver has a individual sound in a bass reflex cabinet.

Does this carry on in the horn cabinet? No electric bass players play into their - horns??
Click to expand...
Glenn Hughes used to like the Martin Audio Type 115 folded horn bins,

Jaco Pastorius loved the Acoustic 360/361 setup which was a Preamp that fed into a powered cab that had a single 18" woofer in a folded horn.
The preamp had four parallel outputs and could be used to feed four of the powered cabs at once.

I am strongly considering building a folded horn cab to use for some electric bass gigs this summer.
 
Glad to be educated.. in my experience - bass reflex cabinets make my walls vibrate. Horns covering the same
frequencies play louder with out the walls moving.
 
Yikes - Deep Purple sure had a sound wall! I saw them in 1972, and had to many mushrooms to notice the horn bass.

No wonder they were playing LOUD and clear.!!
 
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