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Cornwall IV

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2 hours ago, mustang_flht said:

Chef Bonehead is the designer 😎

 

Years ago, in a Usenet newsgroup, I witnessed a hilarious argument about psychoacoustics. "Person A" would say something, and "Person B" would respond that no, that's not how it works. The argument grew increasingly heated until finally Person A said to Person B, "You don't know what you're talking about. Here, read these papers to educate yourself and then write back." He then cited a number of AES and IEEE papers.

 

What Person A didn't know was that Person B was "JJ" Johnston, of Bell Labs ... the author of the very papers that Person A cited.

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10 hours ago, dls_123 said:

 just change three capacitors and maybe one or two resistors.

wrong move -the  10 years warranty is voided if you modify the speaker -

 

 

 

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7 hours ago, dls_123 said:

Hi

I am not going to build a new crossover, just change what looks like three capacitors and maybe one or two resistors.  Have to see which crossover is in mine.  Not changing the board out, just a few parts and will use exactly the same values, so not changing the circuit at all and using the same boards.

Looking forward to your impressions as you experiment.  

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22 hours ago, jimjimbo said:

 

How would it be any different?

More so the path I guess, how does the signal split (other than High/low, obivioulsy)  I guess to me the schematic is quit clear. 

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2 hours ago, RandyH000 said:

wrong move -the  10 years warranty is voided if you modify the speaker -

 

 

 

Probably done once any screw is removed. 

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4 hours ago, Edgar said:

What Person A didn't know was that Person B was "JJ" Johnston, of Bell Labs ... the author of the very papers that Person A cited.

Written language is such a poor medium to convey truth...

 

:wink:

 

Chris

 

P.S.: see https://community.klipsch.com/index.php?/topic/167098-what-book-are-you-reading/page/3/&tab=comments#comment-2146906 or

https://fs.blog/2015/12/garrett-hardin-three-filters/

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2 hours ago, RandyH000 said:

wrong move -the  10 years warranty is voided if you modify the speaker -

 

 

 

I don't think he really cares about that.  I wouldn't if I wanted to experiment.

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If one could just think for a second, how the speaker would feel, someone poking and prodding your internals around.

Yes, just paid good money for you and just can't wait to get you in my garage to experiment on you.

Must be the solder...

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5 hours ago, Edgar said:

What Person A didn't know was that Person B was "JJ" Johnston, of Bell Labs ... the author of the very papers that Person A cited.

In the movie "Back to School" with Rodney Dangerfield playing a successful businessman who decided to go back to college and get a degree. Since he had lots of money, he was able to hire people to do some of his homework for him. He even went as far as hiring Kurt Vonnegut  to write a book report on one of Kurt own books! The college professor gave him a low grade and wrote a note saying that Rodney simply did not understand the work of Kurt Vonnegut!! LOL. Funny but true in life somtimes!!!

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When I read of someone doing something like this I'm reminded of my wonderful wife and her habit of tweaking EVERY cooking recipe she's ever followed.  I don't tease her about it but it's clear that it's her way of taking credit for how a dish - that is 99.999% someone else's - turned out.  ..She add's a small dash of this, a sprig of that - two additions that probably aren't noticeable - but she does anyway so that she can tell people, "yes, it's a recipe but I improved it quite a bit.."  

 

 

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On 4/6/2021 at 8:45 PM, dls_123 said:

I am certainly going to listen to them.  I have seen photos of the crossovers.  I am not going to change any values at all, but those are run of the mill poly caps and resistors in there.   Putting a very high quality oil damped poly cap like the VCap ODAM is not going to change the way the crossover works.   It will improve the quality of the signal flowing into the drivers though.  They are a more detailed cap and not bright in any way once they run in for 100+ hours.  I am not trying to be confrontational in any way.  Things are built to a price point.  That is all.   I have built literally over a thousand pieces of tube audio equipment between restorations of vintage and my production custom gear.  I have heard tons of different capacitors.   I understand voicing certainly.   But I can see what caps are in there now and I know what I want to use sounds like.  There is no comparison.  I will keep the oem parts and if I don't like it I will put them back.   I am not going to tell other people what to do at all and post that my way is best or anything like that.  I am sure it is a great speaker.  I had original cornwall I years ago and they improved significantly when I replaced the crossover caps and resistors.  Again, it is not my goal to say anything bad about Klispch or tell others what to do.  I am not trying to offend anyone.  I am not trying make a business of Cornwall crossover mods or anything like that.  No commercial intent whatsoever.  I intend to listen to these for a long time.  I have had a couple of customers with my amps say how much they like them with the Cornwall IV.  One of the customers damped the horns with dynamat or some other similar material and told me he could tell the improvement right away.   I trust him.  So I am just going on my journey that is all.

 

cheers....Don

For me it is exactly the opposite case. I have 1977 Lascala, all original drivers. The Aerovox caps of the AA crossover have been leaking since long time and the values were no longer correct. I bought in 2006 an ALK universal network, which I had exactly 4 weeks  in operation, it was not my idea of musicality. Since 2010 I have Crites AA crossovers, but that was with the sonicaps also not really the sound as in my memory with the Aerovox.

Shortly later I had not used the speakers for 10 years because all the time I listened to Jubilees with K402.

Since three months I have reactivated the old LaScala out of curiosity. Everything is ok, only mids and treble are still too loud and a bit sharp. Although the sonicaps have now settled in after a hundred hours the squaker and tweeter does not sound as in my memory with the original PIO caps in the sense of a homogeneous sound.

So I'm glad that there are now the new original Klipsch capacitors, which another member I quote above would like to remove immediately. The caps Klipsch offers for the old AA xover look the same as in the pic of the new CW4 xover which is good news because the reviews about the CW4 a so very positive around the world. It is not about the „best“ cap in an insulated view but what fits best in the network also in terms of ESR value and so on. So to the price of the replacement caps the selecting process of the polyester (I think so) type has to be added as well as the ordering by Klipsch of today exotic values like 2uF and 13 uF. And that makes a point, even if I would use smaller values to reach 13uF in parallel constellation of caps I would alter the ESR to a „better“ smaller value but which would be probably wrong regarding the network requirements.

The only downside is that shipping and tax plus customs to Germany is in addition more than the price of the caps themselves. Alternatively I could try new motor run caps which I can get over here but I am afraid that the newer PP foils do not behave like the old times PIO and I do not want to waste my time with trying out different caps over and over.

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I don't have a link for you but I remember some Russian caps that might be what you are looking for and perhaps they would be cheaper than imports from the USA. The few times I have run across them on EBay for instance they were pretty cheap on shipping. I have no idea on import fees into Europe.

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Dave, thank for the recommendation, do you mean Russian K75-10 and/or KBG-MN types? That ones I could get i.e. from Bulgaria which is part of the EU via ebay and therefore no customs and cheap shipping. TBH I see two potential issues. This caps are also some decades old, how about value shift and/or ESR shift. If they leak I would be not surprised if they are PCB based as the coolant, at least the KBG-MN types. Soundwise one can read good reports. Or do you have experiences with this types?

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