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La Scala AL 3 Crossover Mod Questions


ka7niq

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21 minutes ago, Deang said:

 

I know you're using hyperbole to make a point, but don't kid yourself -- a paper in oil or film and foil capacitor will always deliver better performance than a metalized type (both measurably and in sound quality).

Really High ESR can sound different, and some of those paper in oil caps have been clocked with off the scale ESR readings.

Ya think maybe, just maybe, the high insertion loss might have something to do with it ?

 

I have a friend that was into these paper in oil caps so much, that he would actually give the caps an oil change

LOL, I told him he should offer a Jiffy Lube Franchise, where folks like you could take their paper in oil caps, to have the oil changed :) 

Supposedly, he listened to several different brands of oils in the capacitors, for sound quality

 

There may be something to what you say DeanG, because Panasonic used to make stereo receivers and integrated amps featuring these kinds of Caps http://www.diyaudio.com/forums/everything-else/31776-panasonic-ta-keh-caps-step-forward.html

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There is a study quoted often out there where a guy used "high end" capacitors which cost up to four and five hundred each. 10% tolerance for many of these jewels and I figure it was tuning sound by inducing distortion for lack of a better word that the end user preferred over stock sound. I tend towards wanting to hear exactly what I would hear at a concert and I know their amps do not use these fancy costly designer caps. I am happy with what I have used and that is what counts and it did not break the bank.

 

 

"I have been a Ham for nearly 37 years, so not into hocus pocus.

Honestly, I think a lot of the differences people hear in Caps comes from replacing bad old caps, with new Poly ones.

I have re capped many vintage speakers, using decent quality bipolar electrolytic capacitors, with excellent results."

 

  THAT is the best viewpoint and if you are well pleased with the result this is good and you saved money doing it. I like the polys  and have no problem finding any value I need and from all I read they have a longer life than I figure I have left and there is always a noticeable improvement over the old stuff.

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Yes, a Jensen paper in oil capacitor has higher ESR than a film or metalized type, but it's not as high as you're inferring. There is also Dielectric Absorption, which no one cares or discusses anymore, though it is a factor. There is also the damping effect that the oil provides ...

 

So, again -- what about "self healing"?  

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3 minutes ago, Dave A said:

Honestly, I think a lot of the differences people hear in Caps comes from replacing bad old caps, with new Poly ones.

 

Well of course, no doubt -- no one would dispute that.

 

But consider -- the vintage stuff was voiced using capacitors with higher ESR than modern polypropylenes. This is why the older networks produce a sound that is too forward.

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Just now, Dave A said:

 

 

  THAT is the best viewpoint and if you are well pleased with the result this is good and you saved money doing it. I like the polys  and have no problem finding any value I need and from all I read they have a longer life than I figure I have left and there is always a noticeable improvement over the old stuff.

Honestly, just between you and me, I almost just used ALL ERSE Electrolytics, to re cap my LaScala AL 3 crossovers.  My left and right brain had a knock down drag out fight over it. 

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1 minute ago, Deang said:

 

Well of course, no doubt -- no one would dispute that.

 

But consider -- the vintage stuff was voiced using capacitors with higher ESR than modern polypropylenes. This is why the older networks produce a sound that is too forward.

B&W actually go out of their way to warn people about replacing caps in their speakers with low ESR Poly Caps !

IMHO, Poly Caps are not automatically better, because sometimes the speaker designer depended on the higher ESR of their Mylar or Electro cap.

I hate to admit how many vintage speakers I ruined, by changing the caps to low ESR Poly ones.

 

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5 minutes ago, Deang said:

All true. You'll get no disagreement from me. 

I am told that higher ESR can cause insertion loss or a Dip around the crossover point.

And lower ESR Poly Caps can cause drivers to run hotter (brighter) and give a Peak at the crossover point.

Now, Floyd Toole and his team of Canadian researchers, found out it is Far better to have a Dip in the response vs a Peak, if you are gonna have any deviation from flat response ! 

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1 minute ago, ka7niq said:

I am told that higher ESR can cause insertion loss or a Dip around the crossover point.

And lower ESR Poly Caps can cause drivers to run hotter (brighter) and give a Peak at the crossover point.

Now, Floyd Toole and his team of Canadian researchers, found out it is Far better to have a Dip in the response vs a Peak, if you are gonna have any deviation from flat response ! 

Yes, higher ESR creates more loss (because of the higher resistance).

 

Yes, lower ESR capacitors cause the drivers to sound "louder".

 

Yes, Floyd is right. He's always right.

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4 minutes ago, Deang said:

As for your AL-3s, you could use all Mylars and be perfectly fine. The sound may not be as clean as it could be, but it would be balanced -- which is really important.

I already ordered all Poly, except for the 68uf caps in the woofer circuit, and they are here, but guess what ?

I may just sell them, because my experience tells me they will make the LS more bright/forward

 

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9 minutes ago, Deang said:

Yes, higher ESR creates more loss (because of the higher resistance).

 

Yes, lower ESR capacitors cause the drivers to sound "louder".

 

Yes, Floyd is right. He's always right.

If  I piss anyone off, please forgive me, but the LAST thing you want a LaScala with the AL 3 crossovers to do, is make the mid range any louder. 

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13 hours ago, ka7niq said:

If  I piss anyone off, please forgive me, but the LAST thing you want a LaScala with the AL 3 crossovers to do, is make the mid range any louder. 

Yesterday I bought what was supposed to be a pair of KP-201's. What they really are I don't know. Inside on the mid horns though was a pair of soldered lug K-55V's. Now researching these led to discussions on K-55M vs K-55V and K-55V soldered lug drivers and how some (K-55M) would sound to bright on, you guessed it, AL-3 crossovers.  Different behavior on A and AA crossovers. All things being equal with a pair of La Scalas the AL-3 were brighter than the AA's were with a K-55M driver but I liked the highs the K-55M brought to things like cymbals on this setup. The K-55M on the AA crossover was more muted on mid and high range but sounded better with blues and old pipe organ music. So add to the mix matching the driver to the crossover. Apparently K-55 whatevers and crossovers are not mix and match.

 

 For the first time I had newly recapped crossovers and a pair of La Scalas to play with at the same time and I am finding out the mid drivers need to be matched to them to complete the effort.

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1 minute ago, Dave A said:

Yesterday I bought what was supposed to be a pair of KP-201's. What they really are I don't know. Inside on the mid horns though was a pair of soldered lug K-55V's. Now researching these led to discussions on K-55M vs K-55V and K-55V soldered lug drivers and how some (K-55M) would sound to bright on, you guessed it, AL-3 crossovers.  Different behavior on A and AA crossovers. All things being equal with a pair of La Scalas the AL-3 were brighter than the AA's were with a K-55M driver but I liked the highs the K-55M brought to things like cymbals on this setup. The K-55M on the AA crossover was more muted on mid and high range but sounded better with blues and old pipe organ music. So add to the mix matching the driver to the crossover. Apparently K-55 whatevers and crossovers are not mix and match.

 

 For the first time I had newly recapped crossovers and a pair of La Scalas to play with at the same time and I am finding out the mid drivers need to be matched to them to complete the effort.

I got hold of an old LaScala brocure, and evidently the mid range driver level was adjustable at one time! 

It would have been nice of Klipsch to allow adjustment of the drivers IMHO

 

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On 12/16/2017 at 11:02 AM, ka7niq said:

I got hold of an old LaScala brocure, and evidently the mid range driver level was adjustable at one time! 

It would have been nice of Klipsch to allow adjustment of the drivers IMHO

 

 

That is why the autoformer is is the circuit. I dropped the mids about 3 db in my LS, making the balance a lot smoother.

 

You could also triamp and use a dsp crossover to you could time align the drivers AND adjust the levels.

 

Bruce

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On ‎12‎/‎16‎/‎2017 at 11:02 AM, ka7niq said:

Now researching these led to discussions on K-55M vs K-55V and K-55V soldered lug drivers and how some (K-55M) would sound to bright on, you guessed it, AL-3 crossovers.  Different behavior on A and AA crossovers. All things being equal with a pair of La Scalas the AL-3 were brighter than the AA's were with a K-55M driver but I liked the highs the K-55M brought to things like cymbals on this setup. The K-55M on the AA crossover was more muted on mid and high range but sounded better with blues and old pipe organ music.

 

This doesn't sound right to me.

 

The AL series of networks were designed to work with the K-55-M driver. The K-55-V drivers were mated with the Type A and AA.

 

Bob tested all of these different drivers many years ago, and found that there was a negligible difference in output between them. 

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1 hour ago, Marvel said:

 

That is why the autoformer is is the circuit. I dropped the mids about 3 db in my LS, making the balance a lot smoother.

 

You could also triamp and use a dsp crossover to you could time align the drivers AND adjust the levels.

 

Bruce

I have the AL 3 crossover Bruce

How do you go about dropping the mids ?

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11 minutes ago, Deang said:

You can't. Unless ...

 

You go with an aftermarket autotransformer, do some math, and then size the primary capacitor accordingly.

 

Or ... dump the AL-3 and buy a constant impedance design with adjustable tap settings.

Or buy an L-pad.  Why you always gotta do things the hard way Deano?

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