Academy crossover upgrade - an obvious challenge

[popbumper]

Dean:

I should have an answer for you sometime in the near future; my crossovers will employ both Solen and Dayton capacitors in the LF section.

Popbumper

[lipinski]

This probably needs to be a separate thread, but ya'll jump right into these discussions about crossover upgrades and the "how to" angle, but can somebody kindly explain why one would want to perform a crossover upgrade. My simplistic mind wants to buy the best speaker I can find and leave it alone. Since this is not my trade and I've never embarked on a project like this before, I'd be terribly afraid that I get the electronic upgrade correct which may give me a slight improvement, but I'd not re-assemble the speaker box, or insulating material just rate and get a considerably worse sounding speaker. Nevertheless, I'd love to know what you guys are trying to accomplish with these upgrades. BTW, I'm not an electrical engineer, so keep it simple.

[ka7niq]

On 1/3/2005 at 2:53 AM, Crankysoldermeister said:

It'll be interesting to see if any benefit is derived from replacing the electrolytic(s) in the LF section of these networks with an inexpensive Solen or Dayton. I've convinced myself that it's a waste of time and money. Has anyone done it yet, because I sure haven't.

I'm getting ready to do an Academy. Not much to it really. If you leave the electrolytics in place (and I will), there should be plenty of real estate. I might replace them with some axial types and bypass them -- and see what the customer says.

If there are electrolytics in there, they should be replaced. Think about it ? If a speaker was made in 1990 the caps are 32 years old! 32 years in no problem for a Mylar Film Cap, but not so with an electrolytic Cap! They lose value, and as a result no longer have enough capacitance to keep the LF out of the midrange!

 

 

[Deang]

From 2005, lol.

[ka7niq]

2 minutes ago, Crankysoldermeister said:

From 2005, lol.

LOL, every old thread is  new again. When I reply to a post, I am not necessarily replying to the poster, but adding to the knowledge base

The Klipsch Academy Center Speaker was only made from 1992 to 1994 https://www.klipsch.com/products/academy-center-speaker

[Frzninvt]

I was the first to try Popbumpers Academy network and it literally transformed it.  I had a lengthy post back them that I titled "An Academy Tale" the stock network is an obvious compromise.  The detail and clarity really increased with his network installed keep in mind is did not come cheap but it is worth it.  I know which one I would choose between the stock network and the K-Stack.

[Deang]

He made a really nice product.

[jimjimbo]

5 minutes ago, Crankysoldermeister said:

He made a really nice product.

Yes sir.  Certainly helps when you use good quality parts......

[001]

On 5/20/2022 at 12:08 PM, ka7niq said:

If there are electrolytics in there, they should be replaced. Think about it ? If a speaker was made in 1990 the caps are 32 years old! 32 years in no problem for a Mylar Film Cap, but not so with an electrolytic Cap! They lose value, and as a result no longer have enough capacitance to keep the LF out of the midrange!

 

 

 

mylar caps can degrade with age/use too.  i have replaced original caps in chorus2 & forte 2 as well as other brands of speakers with budget poly caps that made a very noticeable improvement. 

 

electrolytic caps in most 2 & 3 way klipsch speakers are in the woofer circuit, they dont keep low freq out of the midrange as far as im aware but i could be wrong.  the mylar caps filter the LF from the midrange & tweeter.      

[ka7niq]

1 hour ago, EpicKlipschFan said:

 

mylar caps can degrade with age/use too.  i have replaced original caps in chorus2 & forte 2 as well as other brands of speakers with budget poly caps that made a very noticeable improvement. 

 

electrolytic caps in most 2 & 3 way klipsch speakers are in the woofer circuit, they dont keep low freq out of the midrange as far as im aware but i could be wrong.  the mylar caps filter the LF from the midrange & tweeter.      

A Poly Capacitor is the very lowest loss capacitor. Inherently, they have lower ESR than a Mylar, so I think that is what you heard. Usually, Mylar Capacitors keep their VALUE forever.  But, according to Bob Crites, they can develop high ESR as they get old. 

 

Those electrolytic capacitors are on the woofer roll off circuit, and if they lose value, the woofer will not roll off as soon. In a 2 way speaker like the Academy Center Channel, those dual 8 inch woofers are crossed over at 2.2 k. This means they are the midranges! 

[001]

20 hours ago, ka7niq said:

A Poly Capacitor is the very lowest loss capacitor. Inherently, they have lower ESR than a Mylar, so I think that is what you heard. Usually, Mylar Capacitors keep their VALUE forever.  But, according to Bob Crites, they can develop high ESR as they get old. 

 

Those electrolytic capacitors are on the woofer roll off circuit, and if they lose value, the woofer will not roll off as soon. In a 2 way speaker like the Academy Center Channel, those dual 8 inch woofers are crossed over at 2.2 k. This means they are the midranges! 

 

in the case of one pair of the many chorusii i have owned, it wasnt the change to poly caps that made the difference, the speakers sounded like a towel was covering them, no crisp mid or highs & muddy bass.  the other 2 pairs i owned at the same time with stock caps sounded great.  so something caused the mylar caps in that set to fail, i didnt measure them nor was i capable of measuring ESR, im sure just replacing with the same stock mylar caps would have had the same results.  the original mylar caps were bad either from age or use/abuse from the previous owner but he said he never listened overly loud & he was an older guy that listened to classical or softer type music so i dont think their history caused it. 

 

i trust what mr crites has said about caps & many other things in general about audio, like caps dont "break in" nor do tweeters & smaller drivers etc.  to claim mylar caps dont ever go bad is false based on my experience & many others who have reported improvements in sound when replacing 25-30 year old caps in these era of speakers, even when using the same type of mylar caps, so that shows that mylar caps can & do fall out of spec.  the difference in sound or quality of poly vs mylar caps is a touchy subject around here, some claim mylar are the best caps ever made & you absolutely must use "authorized" caps or else your speakers arent klipsch anymore & that poly caps are cheap snake oil... LOL.     

[ka7niq]

On 5/23/2022 at 11:53 AM, EpicKlipschFan said:

 

in the case of one pair of the many chorusii i have owned, it wasnt the change to poly caps that made the difference, the speakers sounded like a towel was covering them, no crisp mid or highs & muddy bass.  the other 2 pairs i owned at the same time with stock caps sounded great.  so something caused the mylar caps in that set to fail, i didnt measure them nor was i capable of measuring ESR, im sure just replacing with the same stock mylar caps would have had the same results.  the original mylar caps were bad either from age or use/abuse from the previous owner but he said he never listened overly loud & he was an older guy that listened to classical or softer type music so i dont think their history caused it. 

 

i trust what mr crites has said about caps & many other things in general about audio, like caps dont "break in" nor do tweeters & smaller drivers etc.  to claim mylar caps dont ever go bad is false based on my experience & many others who have reported improvements in sound when replacing 25-30 year old caps in these era of speakers, even when using the same type of mylar caps, so that shows that mylar caps can & do fall out of spec.  the difference in sound or quality of poly vs mylar caps is a touchy subject around here, some claim mylar are the best caps ever made & you absolutely must use "authorized" caps or else your speakers arent klipsch anymore & that poly caps are cheap snake oil... LOL.     

I do have the ability to measure ESR, either in or out of circuit, and Bob Crites is correct. Mylar Caps can develop higher then when they were stock ESR values. But I have yet to measure any Mylar Cap that did not have it's value, as far as capacitance goes. In fact, the people who rebuild old radios seldom if ever replace any Mylar Caps, But ESR is seldom a problem for them as long as the cap has kept the other value.  I am re doing the crossover in these horns, and they have 30 year old Mylar caps in them. I measure them, and they have kept their values, but ESR is higher then I would like. They take a 17UF Cap, kind of an odd value. So I found some AC Fan Poly Caps for them! These are sort of like the motor run caps, but smaller and are 450 VAC at 5% Tolerance!