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Cornwall B3 Crossover Mod


CANT

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While I was playing around, comparing the K77 to the K107, I also tested out this mod and found that it smoothed the K77 quite a bit so I thought I would share it...

 

In the attached image you will find a drawing of the stock B3 HF network above another drawing of the mod in question. This "mod" is actually the same HF network found in the AB, AB2, AL, AL2, AL3, AK, AK2 & AK3. So really, all you are doing is converting it to an already established Klipsch design by adding the the rest of this filter to what is already there. 

 

I am pretty sure this same modification could also be used on the B, E, and E2 crossovers, requiring only one more part to accomplish but I have only tried it on a B3.

 

Thanks,

 

post-55655-0-31000000-1445362673_thumb.p

Cornwall B3.pdf

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I find the elliptical filter to be unlistenable.

 

So... you find all Klipschorn, La Scala and Belle speakers produced between roughly 1983 and 2001 "unlistenable" because of a piece of the HF network?

 

....I feel like you might be being unnecessarily/unrealistically harsh?

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what is wrong with DJK's personal assessment? He is entitled to have his opinion. I don't find any stock Klipsch horns listenable at all anymore. If the compression drivers have not been modified I have zero interest in listening to them and I feel just about as adamant about woofers needing modification but not quite to the same degree, and this is because to me they sound unrealistically harsh with smeared detail.

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....I feel like you might be being unnecessarily/unrealistically harsh?

 

No, it's that darn elliptical filter that's being harsh!  :P

 

Uh, what's an elliptical filter anyway, and why is it un-listenable?  What exactly does it filter?  :huh:

+++

 

(Forgive my ignorance, I'm trying to figure things out on my own.  I studied the schematics and I'm still not sure what we're talking about.)  

++++

 

I don't find any stock Klipsch horns listenable at all anymore. If the compression drivers have not been modified I have zero interest in listening to them and I feel just about as adamant about woofers needing modification but not quite to the same degree, and this is because to me they sound unrealistically harsh with smeared detail.  -Moray

 

 

I'm a little lost here Moray as usual, but I think we can sort this out.  :)

 

DJK made his comment about the "elliptical filter" being unlistenable, and your comment seems to be about the harshness of the unmodified CD and woofers.

 

Are you both talking about the same harshness, and is the problem the XO filter, the CD/woofers, or both?

Edited by wvu80
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no I was only providing a comment of my own, one that others might consider as harsh as well. For me it was one of those times where had I not heard the difference that mechanical and acoustical damping that I added to the driver and the improvement that it provided and so everything changed but I would never have known that there was a problem in the first place had I never experimented. Previous experience working with dome tweeters (and cone drivers) suggested that compression drivers would (and they do) respond in similar fashion. That's all. If you don't try you don't find out. Buy some 1/8" thick F-11 Acoustical felt and some Dynamat and start experimenting.

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"So... you find all Klipschorn, La Scala and Belle speakers produced between roughly 1983 and 2001 "unlistenable" because of a piece of the HF network?"

 

Absolutely !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

 

It is most noticable on female vocals where it rings and adds sibilance.

 

In his Klipschorn review in Audio, Heyser noticed this problem in the time domain.

 

I unhooked the elliptical portion of the network and the problem went away.

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Should I clip the "elliptic filter"? -- Maybe not!

Posted by djk on 24 November 2000 - 04:11 PM in Technical/Modifications

A Crown TEF analyzer is a big help for measuring speakers.The waterfall plots show that the ellipical filter's problem is a time energy problem not an amplitude response problem.Mis-terminated filters ring.The higher order the filter is the worse it rings.Removing the pole zero at 5khz makes the amplitude response worse.But despite the peak in response in the sibilance region the speaker has audilby less sibilance particularly on female vocals.IE it sounds better.Measurements can be a trap.How do you know if what you are measuring is relavent? Most of the time in audio we measure what we know how to easily measure.This is like the drunk looking for the keys he lost in the back alley of the bar out in front under the street light because the light is better there.He is never going to find what he is looking for.I trust my ears first.Then I try and figure out how to measure what I hear.When I read Richard Heyser's remarks on the TEF response of the Klipschorn a bell rang in my head.I ran to my toolbox and grabbed a pair of sidecutters and snip there went the sibilance.I did not even think about trying to measure the RTA because the response has a series of peaks and dips with an envelope of 6dB that is a half octave wide at the crossover point anyway.This is caused by the drivers being non-coincident and the 1.5msec delay in arrival times.This swamps any amplitude response changes caused by removing the pole zero.As a further point I change AA networks to a textbook 3 pole Butterworth at 4khz and AK/AL/AB networks to a textbook 2 pole Butterworth at 6.3khz and parallel the tweeter in both cases with a 15 ohm resistor.Now math nuts would say that I have made an equal ripple response Chebychev out of the one and a Bessel out of the other. But if you eliminate the resistor and try to build the same response filter by changing the inductor and capacitor values the sound is not the same.The partial answer of course lies in the very complex impedance of horns.

 

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what is wrong with DJK's personal assessment? He is entitled to have his opinion. I don't find any stock Klipsch horns listenable at all anymore. If the compression drivers have not been modified I have zero interest in listening to them and I feel just about as adamant about woofers needing modification but not quite to the same degree, and this is because to me they sound unrealistically harsh with smeared detail.

 

My first guitar amplifier was this little portable thing from JCPenney/Sears. I honestly think it was better at producing feedback and picking up rouge radio signals than it was at actually amplifying my guitar... I feel pretty comfortable saying it was nearly "unlistenable" on many many levels but I still have a hard time speaking too poorly of it. 

 

It's not the opinion I have an an issue with, it the broad sweeping generality. I do understand that he does not prefer the elliptic filter or even for that matter the K77/T35 but I feel like he could have made his comment a bit more constructive?

 

I did find the old thread he quoted above, in which he and ALK discussed this at some length and made his point understood a bit better than he did here...

 

https://community.klipsch.com/index.php?/topic/173-should-i-clip-the-elliptic-filter-maybe-not/

 

I also found a few associated thread that others may or may not find useful if are considering what I proposed or maybe something like it?

 

https://community.klipsch.com/index.php?/topic/53317-alk-what-is-an-eliptical-filter/

 

 

https://community.klipsch.com/index.php?/topic/33247-more-extended-highs-for-aa-network/

Edited by CANT
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what is wrong with DJK's personal assessment? He is entitled to have his opinion. I don't find any stock Klipsch horns listenable at all anymore. If the compression drivers have not been modified I have zero interest in listening to them and I feel just about as adamant about woofers needing modification but not quite to the same degree, and this is because to me they sound unrealistically harsh with smeared detail.

 

My first guitar amplifier was this little portable thing from JCPenney/Sears. I honestly think it was better at producing feedback and picking up rouge radio signals than it was at actually amplifying my guitar... I feel pretty comfortable saying it was nearly "unlistenable" on many many levels but I still have a hard time speaking too poorly of it. 

 

It's not the opinion I have an an issue with, it the broad sweeping generality. I do understand that he does not prefer the elliptic filter or even for that matter the K77/T35 but I feel like he could have made his comment a bit more constructive?

 

I did find the old thread he quoted above, in which he and ALK discussed this at some length and made his point understood a bit better than he did here...

 

https://community.klipsch.com/index.php?/topic/173-should-i-clip-the-elliptic-filter-maybe-not/

 

I also found a few associated thread that others may or may not find useful if are considering what I proposed or maybe something like it?

 

https://community.klipsch.com/index.php?/topic/53317-alk-what-is-an-eliptical-filter/

 

 

https://community.klipsch.com/index.php?/topic/33247-more-extended-highs-for-aa-network/

 

 

 

This probably isn't the best time to be mentioning ALK  around here.  You are much better off doing as you have been and coming up with your own ideas.

 

I like the fact that you came up with something, tried it, liked it, and were willing to share it with everyone to try out on their own.

 

Did you build an entire new network with the mods you mentioned, or just mod your originals?

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  • 7 years later...

Hi   to All  ,


can I ask about  small help ? I assembled cornwall with crossover  B3 ( K-33-e ; K-55-v ; K77) .  Find one  pair  NEW Atlas  sound PD-5VH, change  K-55-V   to  PD-5VH


I need  make any  adjustment  in Crossover B3 ?


I cannot find  any  info  about  this OLD  PD-5VH (  i  think  this  is  very  old  version ) , but  I bought in Sealed Box , absolute New ! check  photos my PD-5VH

 

Anybody  have  an  info  about  this old  drivers  Atlas Sound PD-5VH ?


Help !

rgd Alex

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