La Scala resonance problem

[JohnA]

7 hours ago, codewritinfool said:

I'm no acoustical engineer, but can someone explain to me how anchoring the side wall midway doesn't just push the 150Hz resonance up to 300Hz?

 

 

 

It might, in some materials.  That's why I recommended offsetting the braces from the mid-point of the side wall.  The reality of a La Scala is that the internal damping of plywood will make energy released at 300 Hz much lower than that at 150.  Mine only show a resonance at very high volume.  There just isn't enough energy available below about 110 dB to excite the side panels.  So for most music even at realistic SPLs, the sides don't get excited enough to hear.  AC/DC at their concert levels, well, .......

[ricktate]

When I re-veneered my 1980 Scalas I found that just the veneer on the outside panels greatly stiffened them up. I wished I had documented it. But before the front edge could be flexed very easily….But now I cant even make them flex with my knee and both hands on the other side pulling in. So if your considering re-veneering this would be an extra benefit in doing it I think. I just used the iron on type veneer so was pretty easy and turned out awesome I think.  

[Tony Whitlow]

Yes, it seems that people love their Klipsch speakers so much AFTER they do extensive mods on them around here.   I say if a speaker needs this much in the way of mods, maybe the design isn't so great after all.   I am not saying one should never mod anything. I am just saying that there ARE great speakers out there that do not require all this fuss. 

My LaScalas do not make any annoying sounds. They are 1973 vintage and bone stock. I like if loud too. I just am clueless about these complaints. Paul Wilbur Klipsch would never sell any thing that didn’t faithfully produce sound with no coloration or distortion.


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[twk123]

9 hours ago, ricktate said:

When I re-veneered my 1980 Scalas I found that just the veneer on the outside panels greatly stiffened them up. I wished I had documented it. But before the front edge could be flexed very easily….But now I cant even make them flex with my knee and both hands on the other side pulling in. So if your considering re-veneering this would be an extra benefit in doing it I think. I just used the iron on type veneer so was pretty easy and turned out awesome I think.  

Those look very nice. Did you paint the logo on the squawker with a stencil or is it  a sticker?

[twk123]

4 minutes ago, Tony Whitlow said:

My LaScalas do not make any annoying sounds. They are 1973 vintage and bone stock. I like if loud too. I just am clueless about these complaints. Paul Wilbur Klipsch would never sell any thing that didn’t faithfully produce sound with no coloration or distortion.


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I am happy with mine as well although the were modified by the previous owner with Crites tweeters and crossovers. I think sometimes when people seek to upgrade their Klipsch its assumed the original product was bad or had serious issues. Its more the case of enthusiasts simply loving to tinker with a product with great support and a cottage industry of different options to eek out the extra little bit of performance in ways a company may not be able to feasibly do with a stock product.

[muel]

They are in various condition when we get them as well.  Mine were attached to an organ in a choir loft for nearly 40 years and were quite dry and chipped.  Tightening screws and re-gluing the joints was necessary for them to sound awesome again.  One plus was that the mid and tweeter drivers had been attenuated so they barely saw any use for all those years.  

[jason str]

Never had any rattling cabinet problems with the sets i had, just some bass bin resonance issues at higher volume levels.

 

Since i installed braces on the newer set of La Scala's the problem is gone.

 

[kink56]

I wonder if anyone understands.  I NEVER had rattling cabinets either.   And there is no speaker on the planet that does not have colorations or distortions.  It is impossible.  There is no microphone ever made that does not have colorations or distortions. There are no transducers ever made that do not have colorations or distortions.    PWK is a mortal, he is not infallible, and this is a forum not a church. 

[richieb]

 

- Wow, thanks. First post I have been able to read without my bi-focals. Same font I use when printing shipping labels.

[jimjimbo]

9 minutes ago, kink56 said:

I NEVER had rattling cabinets either.

Yep, it's a witch hunt.

[kink56]

If these speakers did not have colorations and distortions, like every other speaker ever made does, then there would be no need for solutions to problems or modifications designed.  There would only be restorations parts made for aging components.   What use is a forum if EVERYONE drinks the koolaid?  One does not learn anything if everyone agrees.  It ends up being one big circle jerk. 

[jimjimbo]

8 minutes ago, kink56 said:

If these speakers did not have colorations and distortions, like every other speaker ever made does, then there would be no need for solutions to problems or modifications designed.  There would only be restorations parts made for aging components.   What use is a forum if EVERYONE drinks the koolaid?  One does not learn anything if everyone agrees.  It ends up being one big circle jerk. 

Well, that's tempting.

[muel]

20 minutes ago, kink56 said:

I wonder if anyone understands.  I NEVER had rattling cabinets either.   And there is no speaker on the planet that does not have colorations or distortions.  It is impossible.  There is no microphone ever made that does not have colorations or distortions. There are no transducers ever made that do not have colorations or distortions.    PWK is a mortal, he is not infallible, and this is a forum not a church. 

Why are you yelling?  Yeah, we get it... there is no such thing as a perfect speaker.  A person can be perfectly happy with what they have though.  Just as they can be perfectly happy tweaking and changing things endlessly.  

 

[kink56]

Not yelling, I was making sure that people did not think I was talking about my cabinets rattling or buzzing.   It seems whenever I talk about resonance some people think I am saying the cabinets rattle or buzz.  Yes, it is perfectly fine to like your speakers or to mod them.  I have liked speakers, disliked speakers both before or after mods.   

I currently own two sets of Klipsch I am happy with.  I have owned 6 other sets in my life.  I have owned at least a dozen other speakers.  And the fact that no two sound exactly the same is evidence of coloration and distortion.   Both colorations and distortion is something we all learn to live with. In fact some actually seek out (either knowingly or unknowingly) certain colorations and/or distortions they prefer. 

[J M O N]

I've owned La Scalas and agree that they do resonate -- but that was only noticeable to me at higher volumes (levels I don't listen to that often).   My Cornwalls would also resonate at those higher volume levels -- not surprising as it is a big wooden box.  The truth is, all loudspeaker boxes will resonate when energized, it's just the magnitude of the resonance that may differ.  Some boxes have bracing to minimize those resonances (e.g., B&W Matrix series).  The size, material, material thickness, and flexibility of the chosen materials are all factors.  I recall auditioning a speaker many years ago that had concrete as part of the material selection (I can't recall the brand at the moment, but the company is no longer in business).  I do remember it as a good sounding speaker.

 

I do agree with Kink56 that there is no perfect speaker and they all have flaws.  Like everything, there are trade-offs involved.

 

However, I do not agree with ProAc being good speakers -- at least not for my tastes.  They may very well be accurate in their reproduction (if that was the claim), but having listened to them a number of time at a dealer, they never did anything for me.  That same dealer also carried the Thiel brand and I much preferred Thiel over ProAc.  Now, that was many years ago so it could be things have changed.  Everyone does have different tastes, different ears, etc., so I can't argue against anyone liking the ProAc sound.

 

For me, I'm fortunate that I found what I really like and just as important in that regard is that the performance-to-cost ratio is extremely high compared to other quality brands.  While there are many other brands I do like, all things considered, I've yet to find something I like better than Klipsch.

[Full Range]

My La Scala are a DIY build 

They have double thickness side walls 

And 3 braces at Top - Middle - Bottom 

 



 

[ricktate]

11 hours ago, twk123 said:

Those look very nice. Did you paint the logo on the squawker with a stencil or is it  a sticker?

Its a sticker from Christy...….I also put a couple screws into the side of the cabs ….I think I cant really remember its been a while and it was during a hospital stay so I forgot what all I did to them. Any how the sides are freaking stiff now doing veneer would help for sure.

[Schu]

On 7/26/2018 at 10:31 PM, JohnA said:

 

There just isn't enough energy available below about 110 dB to excite the side panels.

 

TADA!

 

 

🙌

[Stefano_2018]

On 7/28/2018 at 10:00 AM, Full Range said:

My La Scala are a DIY build 

They have double thickness side walls 

And 3 braces at Top - Middle - Bottom 

 



 

 

Thanks to everyone for the answers, they were very useful.
@Full Range, how did you fix the supports in the highlighted point?

Thank you
Stefano

Edited July 30, 2018 by Stefano_2018

[Full Range]

 

 

1 hour ago, Stefano_2018 said:

 

Thanks to everyone for the answers, they were very useful.
@Full Range, how did you fix the supports in the highlighted point?

Thank you
Stefano

 

 

I was not the original builder 

But I had a look and it looks like glue 

However it’s also possible that the builder used a biscuit joiner to hold them in place ( I would have done that )

 

Here is a photo of the rear as it was being built & before the double side wall was added