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La Scala Sound Quality Issue


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I have a set of 1973 La Scalas that are new to me.  I also have a set of Cornwall 1's. 

 

Rebuilt the La Scala AA crossovers with a kit from Crites.  I didn't see much in the way of tutorials online for the AA, but I wired them exactly as they were with the originals and compared to reference images I could find online.  I replaced the K77 tweeter diaphragms, so they appear to be fully functioning.

 

Cornwalls have Crites crossovers.

 

Here's my issue.  The La Scala sound terrible compared to the Cornwall.  The midrange sounds like someone singing down a tube and some distortion.  I've messed with placement and toe-in.  I also tried the same placement as where I had the Cornwalls.  The room I have is about 20x15.  I've never heard La Scalas before, but I can't imagine they are supposed to be this bad.

 

My assumption was that the La Scalas would sound very similar to the Cornwalls with less pronounced bass and a better midrange. Can anyone take any guesses as to what's going on?

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I hope, given your ability to build a network and replace a diaphragm, that you didnt think that room placement and clocking would solve a distortion issue...

 

The idea of  horn coloration is a non sequitur in my humble opinion when it comes to the La Scala or Klipschorn.

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I think we should leave any enforcement of the rules to the moderators. 

 

We should always be interested in helping somebody figure out a problem. It’s not like he’s here shilling.

 

The sound you are describing is what one might hear with no tweeters, yet you said you changed the diaphragms out. You should start by double-checking that they are actually working.

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@GravityBored

 

Your comments sound very familiar.

I have a pair of '82 Cornwalls that I bought in the summer of 2022 and had listening to almost ever day for a year. A friend had a pair of '83 La Scala Industrials that had been sitting mostly unused for a couple of years (or more) that needed some cosmetic work, so I brought them to my house last summer ('23) to do the work. When I finished I hooked them up positioned in front of my CWs and put my chair back a few more feet.

 

The sound I heard is like you describe concerning the tunnel effect, it was terrible with all the music coming from between the speakers. I listened the next day and the next day and all of a sudden the width made a dramatic change with soundstage becoming very wide, it was quite unexpected.

The only thing I could think of that caused the change was my ears/brain getting used to and adjusting to, I will just let JA from Stereophile explain it from his measurements of the AL5 La Scala:

 

"This can be seen in fig.3, which shows the La Scala's step response on the tweeter axis. All three drive units are connected in positive acoustic polarity, but the tweeter's output arrives first at the microphone. The output of the midrange unit doesn't arrive at the microphone for another 1.5ms, while the woofer's output starts to arrive 2ms after that. Although the arrivals of all three horn outputs are within the ear's tolerance for arrival time difference (footnote 2), such behavior could interfere somewhat with stereo imaging precision."

 

This may have nothing at all to do with the dramatic change, but is the only thing I could think of that might have caused it. After that initial time the soundstage has always been more normal and similar to what I have experienced with various speakers in this same space over 30 years.

The midrange horn on the LS is much deeper than the CW1.

 

 

One other thing happened, the owner complained about the bass and wondered if something was wrong with the woofers. When I first hooked up just the bottoms (I did the work needed on them first) they didn't sound very good to me, so I played bass heavy music through them for several days to loosen up the driver/spider and they soon started to sound better.  

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I can confirm it. As far as I can tell, my old LaScala is one of the speakers I know that takes the most getting used to. It's a psycho-acoustic wonder. My speakers are well-rehearsed, nothing changes anymore. But when I put them away for two months to listen to my BBC speakers, for example, the first day back with the LaScala took some getting used to, to put it mildly, harsh, metallic violins, thin bass colored treble etc etc. The second day they sounded completely normal and from the third day on the sun rises and never sets again.

 

I'm not saying that the topic starter has not legitimate reasons to check everything technically. BTW @GravityBored if you look, I have made threads on the capacitors and the autoformer of the AA Xover. You are brand new to the forum, so you may not know. But the original Klipsch capacitors, which are now available from JEM (see above in the technical section) will make your LaScala sound completely original again. You can also buy the original Autoformer again. The one in your third party crossover has different values and makes the midrange horn sound unnatural. Don't ask me why I know all this.

 

BTW @OO1 had posted somewhere the real good diaphragms, because there are a lot of cheap bad copies around..

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20 hours ago, GravityBored said:

I have a set of 1973 La Scalas that are new to me.  I also have a set of Cornwall 1's. 

 

Rebuilt the La Scala AA crossovers with a kit from Crites.  I didn't see much in the way of tutorials online for the AA, but I wired them exactly as they were with the originals and compared to reference images I could find online.  I replaced the K77 tweeter diaphragms, so they appear to be fully functioning.

 

Cornwalls have Crites crossovers.

 

Here's my issue.  The La Scala sound terrible compared to the Cornwall.  The midrange sounds like someone singing down a tube and some distortion.  I've messed with placement and toe-in.  I also tried the same placement as where I had the Cornwalls.  The room I have is about 20x15.  I've never heard La Scalas before, but I can't imagine they are supposed to be this bad.

 

My assumption was that the La Scalas would sound very similar to the Cornwalls with less pronounced bass and a better midrange. Can anyone take any guesses as to what's going on?

 

 where did you buy the diaphragms for the k-77 ,  what did you buy  , originals or aftermarkets ?   

 

-  swap the  Lascala tweeters and midrange drivers   into the Cornwall and see if the problem follows   

-  take an Ohmmeter,  check the resistance for the Lascala HF drivers/  K-55V midrange / K-77  tweeters  ,  the K-77 are 8 Ohms , the K-55V are 16 Ohms ,  

 

-   .get your crossovers checked by JEM 

 

@JEM Performance

https://jemperformanceaudio.com/capacitor-kits    ,  

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What equipent is driving the lascalas?  Could it be a synergy issue, and nothing really wrong?

 

Sounds like you made careful repairs.  But, Sonicaps can leave a brittle sound.  As mentioned already there are kits available with factory replacement parts that return the speaker to original performance.

 

It also has been mentioned already but some of the replacement diaphragms out there are seriously sub par.  Not sure where you go to get the proper ones.  This is a concern.

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@mark1101

Speaker Exchange (reconingspeakers.com) sells the factory part. Klipsch parts of course also has them, but you don’t get the instant turnaround. For the life of me I can’t figure why Klipsch doesn’t have an online store for most requested items. 

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This sounds like more than a capacitor related issue. He said he’s running them in his Cornwalls, and the LaScala’s sound terrible by comparison. 

So, I would recheck the wiring, and check to make sure the tweeters are actually working. 

 

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“somebody” on YouTube loves sonicaps and badmouths and “fixes” klipsch speakers, but the inevitable result is that well of course he doesn’t demo before and after and sensitivity is greatly reduced when he does produce the after specs.  Distortion sounds like a bad component or loose/damaged diaphragm though. The mod world will never tell you to use factory parts because they make a living off visually fancy high margin parts.  Physics doesn’t care how cute the part looks.  Perhaps klipsch should do a speaker line that displays the crossover and make it visually appealing for the people that want that custom look similar to custom pc builds and car stereos. 

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Stephen, I honestly have the impression that your statements are somewhat confused. Sonicaps don't sound quieter than original Klipsch caps. They even sound louder, but negatively louder, sharper, more metallic and edgier. They have a Q that is absolutely not compatible with Klipsch midrange horns. I don't share your idea that Klipsch should make the Xover a showpiece. It should remain inconspicuous, it is only a means to an end.

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29 minutes ago, KT88 said:

Stephen, I honestly have the impression that your statements are somewhat confused. Sonicaps don't sound quieter than original Klipsch caps. They even sound louder, but negatively louder, sharper, more metallic and edgier. They have a Q that is absolutely not compatible with Klipsch midrange horns. I don't share your idea that Klipsch should make the Xover a showpiece. It should remain inconspicuous, it is only a means to an end.

Whatever the mod guys do it reduces sensitivity and thus dynamics.  
 

The McLaren edition is an example that would benefit from showing the crossover like one would make a car engine visible. 
 

Different strokes for different folks.  Klipsch is big enough to do it all while keeping heritage line classy and McLaren line racy and all things in between. 

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6 minutes ago, Marvel said:

I know that isn't true across the board.

Do you have any independently verified examples?  I mean sure I could slap on the Jubilee Celestion driver atop my AL5 and make it more sensitive.  Already verified that.  But the usual networks upgrades with “high performance” components across the board lowered sensitivity in every case I read.  Happy to look at an outlier, but the OP is unhappy precisely because of the choice to go 3rd party.

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