Question on strange LaScala behavoir

KlipschFan61

KlipschFan61

Smooth Jazzer
I'm not technical enough to present this question in terms that an engineer would be able to recognize instantly but I'll try to put it into words at least I understand.

I noticed while listening to a CD that featured mostly Jazz guitar licks (Emily Remler, if you must know) I was picking up a very uncomfortable "harmonic" from the mid-range horns that actually hurt my ears. I was sitting about ear level with the squawkers, about 8 feet from each speaker at a modest to low level of volume.The effect would dissipate as I moved above or below the level of the centerline of the throats of each squawker. It felt like a "warbling or pulsating effect" that my ears picked up and create a painful, almost throbbing feeling in my head. I eventually had to change my seating position and then source material as it was starting to give me a headache.

Is this the result of a set of AA crossovers aging or something more insideous, say like poor speaker design or something as simple as sitting too close to the horns?

Inquiring minds, and sore ears, want to know.
 
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They're '78's and no, I haven't recapped them. I was hoping that since I had not rebuilt the networks, the squawker was probably operating outside it's normal range and getting a bit "hairy", so to speak.
I had planned to get new caps after the silly season. I feel guilty if I buy stuff for myself when I haven't finished buying things for Christmas.
 
KlipschFan61 said:
I had planned to get new caps after the silly season.
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Same here. Yours and mine are both probably out of spec, and would explain your trouble. Mine have the "dreaded" AL network. I am still a bit unsure as to what crossover I want to use.

Crites or ALK?:dunno:

I may just do a simple recap to hear if I like the sound better with the current AL network. They sound pretty good to my ears, but can get a bit edgy when driven hard.
 
My plan right now is to do a simple recap to bring them back to spec.

After that if I believe they need further tweaks, I'll work from there. I didn't get a lot of feedback on practical mods to LaScalas but I think I have enough input to consider some things that might help.
 
Urizen said:
I am still a bit unsure as to what crossover I want to use.

Crites or ALK?:dunno:

I may just do a simple recap to hear if I like the sound better with the current AL network. They sound pretty good to my ears, but can get a bit edgy when driven hard.
Click to expand...

I've never heard/bought anything from Bob so this is a bit one sided. My understanding is Bob tends to build to factory spec? With Al, you can get perhaps similar, up to his extreme slope networks.

I've got a pair of Extreme slope networks in my LaScalas (1979's with old AA's)

After having his ES networks on my Khorns I will admit to not having an "OMG" moment with them (My Khorns had AK3's which i understand were decent themselves)

the point I'm driving to is... I have since then been able to do a side by side comparison, same speaker, using a 24 db slope network and a 48 db slope network. (I do not know how those compare to Al's in degree of slope)

During musical passages ONLY, I'll admit that I didn't hear much of any difference. On vocals however, I finally DID have an "OMG" moment and there is 100% zero doubt in my mind that the steeper slopes sounded noticably, clearly, unequivicially better than the more shallow slopes.

I've heard people use the phrase "it was like a veil was taken off her voice" and NOW I finally know what they mean because that is EXACTLY how I would have described it (when using the steeper slope)

So, my opinion would be, if "Mr. Budget" is allowing, I'd strongly suggest giving Al a call and go with his ES networks.
 
I have La Scala II's and have no intention of modding them at all. They are great.

I am a past la Scala owner that were 88's with the AL network. The AL network is absolutely terrible.

Before ALK released the ESN designs, he built me a pair of his ALK Universal A networks. Unbelievable difference. Worth every penny. That move is actually got me stuck on speaker moddin and tinkerin'.

Anyway.....I have done other projects.....been through 3 other ESN for odds and ends. The ESN's to my ears are fabulous. I am not a big fan of the mid caps in the High pass filter being Solens though. I like an upgrade in those caps. ALK might not like me saying that comment....but each his own.

Bob brought a pair of my B-3 networks in my late Cornwalls up to spec. That made a big difference to. I have also had a pir ALK Type B's for Cornwalls too. Love the heck out of those.

Bob is a great resource for all of your klipsch upgrades, parts, inforamtion and so on. Done a lot of busines with him.


I recommend you NOT bring a pair of AL networks up to spec.

The cats meow in my opinion for the La Scala upgrade w/o changing drivers and horns would be to get the ALK ESN500 and ESN5800 combo. I would want to splurge even further and upgrade the in series midcaps 0n the ESN500. This is expensive and will cost more than the value of the 77' or 88' lascala. But I'm just crazy anyway.

A reality with ESN's.....IMO...is that they aren't for you if listen to low level dB. If you jack the volume a little..........:banana::banana::banana::banana:

jc
 
KlipschFan61 said:
Is this the result of a set of AA crossovers aging or something more insideous, say like poor speaker design or something as simple as sitting too close to the horns?
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Poor design perhaps, many people have that reaction to LSs. The LSs have peaky response, narrow dispersion and a higher level of throat distortion than many other large horn speakers. Combine that with the poor bass response and resultant midrange heavy tonality and you've a recipe for headaches. If a resonance in the music being reproduced matches a resonance or peak of the speaker's the result is a big blackboard, know what I mean?

A old pal of mine and retired Western Electric engineer named Max Potter, who was a pal of PWK's too, designed a simple filter to kill a 9khz flare that existed in many, but not all, of the Atlas midrange drivers PWK used to use. I named it the P Trap as a joke working on Potter and Khorn.

Ole Max taught me and several people around the Klipsch forums a great many things, maybe some will come forward and give credit.
 
After reading a thread like this I'm glad I converted these home-brew cabinets from 30 years ago to Altec 2 way's crossed over at 800hz, these were used in a large banquet hall until they became part of a luxury apartment home theatre!! :no:
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KlipschFan61 said:
My plan right now is to do a simple recap to bring them back to spec.

After that if I believe they need further tweaks, I'll work from there. I didn't get a lot of feedback on practical mods to LaScalas but I think I have enough input to consider some things that might help.
Click to expand...

Back to the topic. I will be recapping mine shortly just posted a thread two days ago on very topic. If you are sticking to original here is what I found out:

Sonic caps are suppose to be very good per a couple of threads I read here on AK.
http://www.soniccraft.com/sonicaps.htm

You can download the AA cross over schematic and parts list here

http://home.comcast.net/~wooferboy/The_Audio_Engineering_League.html

Enjoy and I hope this helps
Jim
 
Did this thread suddenly shrink or am I just suffering from some sort of spatial dementia?

Thanks for the link Jim. Unfortunately, the drop-downs for the custom crossovers as well as the parts list didn't come up for me. I would definitely like to build my own networks. I think it would be fun plus add a bit of pride factor to the old girls. I've had these LS's for 17 years now and have dragged them from multiple living spaces as well as across the entire country and I'm not about to give up on them yet.

At least it sounds as though this problem I'm having is easliy fixable.

Edit: After a little experimentation, I found that elevating the front edges about 2" has helped. I took a cue from the LS II's on that one. I also added the JBL sub into the mix to perk up the low bass response and the sound had improved quite a bit. Time for cap replacement!
 
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