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crossovers


rbtwsp

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3 hours ago, rbtwsp said:

At some point do crossovers require rebuilding? If so how do you know.....judge by sound?

Some of the older crossovers from the pre-1980's in speakers like the La Scala and Khorn had capacitors in them which need to be replaced because the sound gets a little dull compared to when they were new.

 

Most newer speakers have more modern components and do not need to have their XO's rebuilt.

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7 hours ago, wvu80 said:

Some of the older crossovers from the pre-1980's in speakers like the La Scala and Khorn had capacitors in them which need to be replaced because the sound gets a little dull compared to when they were new.

 

Most newer speakers have more modern components and do not need to have their XO's rebuilt.

 

So, what would the predicted life of my AK4 crossovers for Khorns be?  I bought them from Klipsch in 2005; they were new. 

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1 hour ago, garyrc said:

 

So, what would the predicted life of my AK4 crossovers for Khorns be?  I bought them from Klipsch in 2005; they were new. 

AK-4.thumb.jpg.d1af36a688dbb1e916c668326bf24adc.jpg

 

Gary, it appears that the caps are mylar so their life in domestic use would be in the tens of years.

This link https://www.illinoiscapacitor.com/tech-center/life-calculators.aspx  has a calculator. But if you are concerned you could buy a capacitor tester and carefully unsolder the caps and test them.

 

Now, whether a newer esoteric expensive film cap would sound better is a whole different kettle of fish !        

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17 hours ago, rbtwsp said:

Klipsch CF-3, version 3, I believe

That would make them 1996, so they are 22 years old.

 

I think a rule of thumb would be replace caps after 20 years but your mylar caps don't deteriorate like the old Paper in Oil (PIO) caps.

 

I have the CF-4 v1 (1994) and mine sound fine, I haven't replaced anything in the XO and have no plans to in the near future.

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10 hours ago, garyrc said:

 

So, what would the predicted life of my AK4 crossovers for Khorns be?  I bought them from Klipsch in 2005; they were new. 

Generally I think of modern caps as having at least a 20 year life.  Your AK-4's are a good XO from everything I've read.

 

I just checked Crites' site and he doesn't even offer a kit for the AK-4.  The rebuild kit for the AK-3 is $123.

https://critesspeakers.com/prices-crossover_repair_kit.html

 

If you need more information than my superficial knowledge, check with @BEC As you know, he's The Man when it comes to XO rebuilds. 

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I'm with wirunna, but do a visual, and a sniffer test. If you smell something burnt, or leaking, replace them. That being said, 13 years your fine. Unsoldered and testing each cap is too much work. Keep in mind your ears get weaker with time, especially listening to speakers that are capable of 120 decibels. Save your money, make an appointment with ear doctor, have ears cleaned and checked. I'm 63, my right ear hearing is half of my left, you just live with it.

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22 hours ago, wvu80 said:

Some of the older crossovers from the pre-1980's in speakers like the La Scala and Khorn had capacitors in them which need to be replaced because the sound gets a little dull compared to when they were new.

 

Most newer speakers have more modern components and do not need to have their XO's rebuilt.

Exactly correct, I asked Roy when considering replacing them in all our old Forte's and he said I shouldn't worry about them because it was not the same as the old caps. I forget the name he said they were compared to the old caps but a much longer lifetime.

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1 hour ago, dtel said:

 ... I asked Roy when considering replacing them in all our old Forte's and he said I shouldn't worry about them because it was not the same as the old caps. I forget the name he said they were compared to the old caps but a much longer lifetime.

Here are some measurements from capacitors that came out of some Heresy II. The Forte, Forte II, and Cornwall II uses the same part. 

 

 

53CC2C23-D751-43C4-A0F6-C374F4999504.jpeg

4A68CC0B-150C-4286-AE14-9332876A8A79.jpeg

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Here’s one from one of the AL or AK series of networks. It’s so bad it choked the meter. 

 

What you will notice about all of these is that capacitance is fairly close, but ESR is through the roof. Well, except this one. I mean, it’s a 2uF capacitor measuring out at 657.9pF

 

 

32094887-9C40-4611-BEEF-66978CF9FD76.jpeg

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Newer caps are called mylar. They don't break down like ones of the past. Although ironically the top 1 percent tolerance caps, Mundorf available from Germany are silver and gold, and oil filled and ridiculously expensive. Like $150.00 to $800.00 each, Yikes! At that price point you've got the 10 bedroom mansion, and money is just an item that your accountants keep track of. Bill Gates kind of money.

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How do you know you need rebuild or some new networks? Well, you can just use some common sense. Most things 40 years old could probably use some help.

 

Also, the inside of a loudspeaker is a terrible place to be. All of the old PCB stuff I work on - most of the capacitors have rattled loose and are being supported by their leads. The leads aren’t soldered into the cap, and I suspect years of being subject to constant pounding and vibration is just doing them in. 

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25 minutes ago, Moosee1955 said:

Newer caps are called mylar. They don't break down like ones of the past. Although ironically the top 1 percent tolerance caps, Mundorf available from Germany are silver and gold, and oil filled and ridiculously expensive. Like $150.00 to $800.00 each, Yikes! At that price point you've got the 10 bedroom mansion, and money is just an item that your accountants keep track of. Bill Gates kind of money.

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Not true. All of the caps I just posted about are Mylar. 

 

ALL capacitors eventually fall victim to dielectric breakdown. The whole “caps last almost forever” thing just doesn’t hold up.  

 

And where are you getting those Mundorf prices? The largest value they make in the S/G/O is a 10uF, and it costs $221.00. The 2.2uF is $90.76. I could build a whole set of networks using those for less than $800. At any rate, there are better sounding for much less. 

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2 hours ago, roughlytraded said:

i just bought this pair of Cornwall II:  https://www.ebay.com/itm/332775195601

 

they sound great to my ears, but i'm always curious about sonic upgrades like the crites. anyone know if crossover upgrades would be worth it for me? 

Hey, you got those today!  Congratulations!    :emotion-19:    FYI you beat the $914 average price for those Cornwall II's and $1000-1200 is not unusual.  :emotion-21:

 

My advice?  Plug them in and enjoy them for at least a month.  Then get back to the forums, tell us how they sound and then you'll have a better idea if they need upgraded.  I have a feeling you're going to be posting with a smile on your face.  B)

 

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1 hour ago, Deang said:

At any rate, there are better sounding for much less. 

You haven't started a thread lately.  That has the sound of something we would all like!

 

Maybe list some caps in rank order from best to worst, or assign a relative value.  For instance a Mundorf at 8.5 might be above a Dayton Audio at 8.2, but only a little bit.  That would help those of us without your experience to figure out our cost to performance value.

 

And what are those resistors you like?

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8 hours ago, wvu80 said:

That would make them 1996, so they are 22 years old.

 

I think a rule of thumb would be replace caps after 20 years but your mylar caps don't deteriorate like the old Paper in Oil (PIO) caps.

 

I have the CF-4 v1 (1994) and mine sound fine, I haven't replaced anything in the XO and have no plans to in the near future.

My own rule of thumb, is if it is over 30 years old, solid state, tube  preamp or amp, or cd/dvd/ or crossover, replace or live with a lesser experience.  Particularly true with the larger caps found in speaker xovers.

 

How do I support that conclusion. I can't scientifically, but every-time I've replaced old caps, things sounded better. No not different. Better.

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