Is an old XO audible?

killdozzer

killdozzer

Audioholic Field Marshall
If going by ear, could any of you tell a speaker has an old XO?

Or is it one of those "cooking a frog" changes that creep in on you, but if someone suddenly changes your XO, you'd be amazed?

If it's audible, could it be described what you're looking for?
 
Swerd

Swerd

Audioholic Spartan
A very good question. One that requires several long answers.

First, your question directly asks what audible things can we hear if an old crossover has gone bad. There are several possible things that may go wrong with an old, poorly functioning crossover. But there is no single thing that stands out. It depends on the individual drivers and the original intent of the crossover. You might hear noise from a woofer in break-up mode, or you might hear a gap between a woofer and tweeter. The break up noise depends on the music played, but it usually sounds harsh and prominent. A gap between the woofer and tweeter might easily be overlooked. All this is best heard if you can directly compare two speakers identical except for their crossovers.

My second answer is to a question you didn't directly ask, 'what does a poorly functioning or poorly designed crossover sound like?' Underlying this is the fact that many commercially available speakers, when new, come with poorly designed crossovers. I know one particular DIY speaker designer who made his excellent reputation because of this. (I'd like to able to say he made a good living because of this, but that's another story.)

Now is a good time to refer you to this web page, where Dennis Murphy discusses some fundamental issues in crossover design.

The other question you didn't ask is about crossover components themselves, some of which may or may not age and gradually go bad. In general, passive crossovers are made with 3 different types of crossover components, inductors, resistors, and capacitors. Inductors (also known as chokes or coils) and resistors rarely go bad and are not known to age. On the other hand, some capacitors can fail gradually with age or more quicker due to faulty construction. Much of the chatter on internet audio forums about aged crossovers is really about how some very cheap capacitors have been known to go out of spec or fail outright with age. Some of that chatter is correct, but much of it takes some simple facts and pushes them beyond reason.

I don't have enough time, space, or patience to go into a treatise on the different types of capacitors. Wikipedia is a good source of info, and that should keep you busy reading it for some time. A simple summary, as I understand things, for capacitors that appear in most or all audio crossovers appears below:

There are basically 2 types of capacitors, electrolytic and film. Electrolytic caps, often non-polar electrolytic (NPE) caps usually cost much less that the various film types, especially in the past. Some, not all, were so poorly made that many were out of spec when new. In the past 20 years or so, less expensive film caps have become widely available. They seem to be well made, and may never drift out of spec, or fail. To borrow a joke from Dennis, I'll be out of spec long before the film caps in my speakers will be.

Some NPE caps have been known to fail with age, due to drying out, or due to poor manufacturing quality. Again, see Wikipedia for details, especially a page titled Capacitor Plague.

In my opinion, much of the internet chatter in audio forums about aged capacitors comes from NPE caps in older speakers. Some of it may be correct, but how much of it comes because of the so-called capacitor plague? And how much of it came because of poor crossover design when the speakers were new?

Again, the usual caveat, I'm self-taught. I'm not an electrical engineer and I didn't cut my teeth in school learning about these things with proper academic rigor. All this talk about capacitors is limited to those usually used in building passive audio crossovers. There are many other uses of capacitors, but I'm not discussing them here.
 
highfigh

highfigh

Audioholic Overlord
If going by ear, could any of you tell a speaker has an old XO?

Or is it one of those "cooking a frog" changes that creep in on you, but if someone suddenly changes your XO, you'd be amazed?

If it's audible, could it be described what you're looking for?
Depends- if the differences can be easily seen while testing, I would say that it would be audible. Component values drift, but not all components are subject to this- it's mostly capacitors and carbon composition resistors which aren't used in crossovers. If the new crossover corrects variations that hurt the response and overall sound, it can definitely be audible. Is the change going to be a good thing? Maybe.
 
highfigh

highfigh

Audioholic Overlord
A very good question. One that requires several long answers.

First, your question directly asks what audible things can we hear if an old crossover has gone bad. There are several possible things that may go wrong with an old, poorly functioning crossover. But there is no single thing that stands out. It depends on the individual drivers and the original intent of the crossover. You might hear noise from a woofer in break-up mode, or you might hear a gap between a woofer and tweeter. The break up noise depends on the music played, but it usually sounds harsh and prominent. A gap between the woofer and tweeter might easily be overlooked. All this is best heard if you can directly compare two speakers identical except for their crossovers.

My second answer is to a question you didn't directly ask, 'what does a poorly functioning or poorly designed crossover sound like?' Underlying this is the fact that many commercially available speakers, when new, come with poorly designed crossovers. I know one particular DIY speaker designer who made his excellent reputation because of this. (I'd like to able to say he made a good living because of this, but that's another story.)

Now is a good time to refer you to this web page, where Dennis Murphy discusses some fundamental issues in crossover design.

The other question you didn't ask is about crossover components themselves, some of which may or may not age and gradually go bad. In general, passive crossovers are made with 3 different types of crossover components, inductors, resistors, and capacitors. Inductors (also known as chokes or coils) and resistors rarely go bad and are not known to age. On the other hand, some capacitors can fail gradually with age or more quicker due to faulty construction. Much of the chatter on internet audio forums about aged crossovers is really about how some very cheap capacitors have been known to go out of spec or fail outright with age. Some of that chatter is correct, but much of it takes some simple facts and pushes them beyond reason.

I don't have enough time, space, or patience to go into a treatise on the different types of capacitors. Wikipedia is a good source of info, and that should keep you busy reading it for some time. A simple summary, as I understand things, for capacitors that appear in most or all audio crossovers appears below:

There are basically 2 types of capacitors, electrolytic and film. Electrolytic caps, often non-polar electrolytic (NPE) caps usually cost much less that the various film types, especially in the past. Some, not all, were so poorly made that many were out of spec when new. In the past 20 years or so, less expensive film caps have become widely available. They seem to be well made, and may never drift out of spec, or fail. To borrow a joke from Dennis, I'll be out of spec long before the film caps in my speakers will be.

Some NPE caps have been known to fail with age, due to drying out, or due to poor manufacturing quality. Again, see Wikipedia for details, especially a page titled Capacitor Plague.

In my opinion, much of the internet chatter in audio forums about aged capacitors comes from NPE caps in older speakers. Some of it may be correct, but how much of it comes because of the so-called capacitor plague? And how much of it came because of poor crossover design when the speakers were new?

Again, the usual caveat, I'm self-taught. I'm not an electrical engineer and I didn't cut my teeth in school learning about these things with proper academic rigor. All this talk about capacitors is limited to those usually used in building passive audio crossovers. There are many other uses of capacitors, but I'm not discussing them here.
We agree on a lot of this, but I would like to comment on caps- you didn't originally mention polar vs non-polar and that's important although even non-polar caps have a + and a - connection if they're wrapped. The inner end should be connected to the + of the circuit and the outer should be connected to the -, but I'm not sure how much that matters in a crossover- I know it affects the amount of interference in a high voltage circuit like what's in an amplifier, radio, etc.

Electrolytic caps make audiophiles faint, but there are lots of highly regarded speakers that use those. I see all kinds of superlatives used when discussing Klipsch and their older models used some of the most industrial parts I have ever seen in a speaker. They also have much more limited frequency response- I had someone contact me because his Heresy speakers "sounded dull and lifeless"- he was comparing them to a pair of Boston Acoustics speakers that were actually not particularly bright, but they did provide wider frequency response. I measured the Heresies and then looked at the original specs- almost identical, 50Hz-16KHz +/- 3dB. I also checked the caps and they measured OK, so I left them. These speakers didn't sound bad for some music, but I would agree that they didn't sound great when the source material needed wide bandwidth. OTOH, they WERE introduced in 1957 and at that time, tubes were in the typical amplifier, so wide response was kind of a moot point for a lot of equipment. It basically matched FM, which was considered 'good enough'.

That said, I have mixed feelings about any implication from my comment that being introduced in 1957 may mean they're inadequate, having been 'introduced' in 1957, myself.
 
killdozzer

killdozzer

Audioholic Field Marshall
A very good question. One that requires several long answers.

First, your question directly asks what audible things can we hear if an old crossover has gone bad. There are several possible things that may go wrong with an old, poorly functioning crossover. But there is no single thing that stands out. It depends on the individual drivers and the original intent of the crossover. You might hear noise from a woofer in break-up mode, or you might hear a gap between a woofer and tweeter. The break up noise depends on the music played, but it usually sounds harsh and prominent. A gap between the woofer and tweeter might easily be overlooked. All this is best heard if you can directly compare two speakers identical except for their crossovers.

My second answer is to a question you didn't directly ask, 'what does a poorly functioning or poorly designed crossover sound like?' Underlying this is the fact that many commercially available speakers, when new, come with poorly designed crossovers. I know one particular DIY speaker designer who made his excellent reputation because of this. (I'd like to able to say he made a good living because of this, but that's another story.)

Now is a good time to refer you to this web page, where Dennis Murphy discusses some fundamental issues in crossover design.

The other question you didn't ask is about crossover components themselves, some of which may or may not age and gradually go bad. In general, passive crossovers are made with 3 different types of crossover components, inductors, resistors, and capacitors. Inductors (also known as chokes or coils) and resistors rarely go bad and are not known to age. On the other hand, some capacitors can fail gradually with age or more quicker due to faulty construction. Much of the chatter on internet audio forums about aged crossovers is really about how some very cheap capacitors have been known to go out of spec or fail outright with age. Some of that chatter is correct, but much of it takes some simple facts and pushes them beyond reason.

I don't have enough time, space, or patience to go into a treatise on the different types of capacitors. Wikipedia is a good source of info, and that should keep you busy reading it for some time. A simple summary, as I understand things, for capacitors that appear in most or all audio crossovers appears below:

There are basically 2 types of capacitors, electrolytic and film. Electrolytic caps, often non-polar electrolytic (NPE) caps usually cost much less that the various film types, especially in the past. Some, not all, were so poorly made that many were out of spec when new. In the past 20 years or so, less expensive film caps have become widely available. They seem to be well made, and may never drift out of spec, or fail. To borrow a joke from Dennis, I'll be out of spec long before the film caps in my speakers will be.

Some NPE caps have been known to fail with age, due to drying out, or due to poor manufacturing quality. Again, see Wikipedia for details, especially a page titled Capacitor Plague.

In my opinion, much of the internet chatter in audio forums about aged capacitors comes from NPE caps in older speakers. Some of it may be correct, but how much of it comes because of the so-called capacitor plague? And how much of it came because of poor crossover design when the speakers were new?

Again, the usual caveat, I'm self-taught. I'm not an electrical engineer and I didn't cut my teeth in school learning about these things with proper academic rigor. All this talk about capacitors is limited to those usually used in building passive audio crossovers. There are many other uses of capacitors, but I'm not discussing them here.
I appreciate this. But it seemed to me you were finally honing on the sound of old NPE and then you cut short.

thank you for the answer...

It's not so much that I didn't ask about particular components, but deliberately asked broadly as I'm interested in anything that could make an old XO audible.
 
Swerd

Swerd

Audioholic Spartan
I appreciate this. But it seemed to me you were finally honing on the sound of old NPE and then you cut short.
It all depends where in the crossover circuit that old NPE is located. Can't make a generalized statement about it. The only certain answer is to measure the speaker, and to measure the cap itself.
It's not so much that I didn't ask about particular components, but deliberately asked broadly as I'm interested in anything that could make an old XO audible.
Old audiophile ears :rolleyes:.
 
killdozzer

killdozzer

Audioholic Field Marshall
It all depends where in the crossover circuit that old NPE is located. Can't make a generalized statement about it. The only certain answer is to measure the speaker, and to measure the cap itself.
Old audiophile ears :rolleyes:.
Thanks again. I did ask for a purpose. I vaguely remember something that my dad's friend said about refreshing the speakers before he gave them to him. I'm not in a position to contact this friend of his so wanted to see if it's possible to determine if the caps were refreshed/changed.

I must say it would take a lot of concentration, can't find anything wrong with the sound, but I think my ears are even more easily fooled than average.
 
Swerd

Swerd

Audioholic Spartan
That said, I have mixed feelings about any implication from my comment that being introduced in 1957 may mean they're inadequate, having been 'introduced' in 1957, myself.
As long as you have a supply of suitable replacement vacuum tubes, you'll be OK. Be sure to readjust the bias occasionally.
 
Swerd

Swerd

Audioholic Spartan
Thanks again. I did ask for a purpose. I vaguely remember something that my dad's friend said about refreshing the speakers before he gave them to him. I'm not in a position to contact this friend of his so wanted to see if it's possible to determine if the caps were refreshed/changed.
In my limited experience, anytime someone talks about "refreshing old speakers", they're talking about replacing all the old caps with new, sometimes overpriced film caps. There are very expensive film caps that enjoy the same voodoo among the gullible audio community as do exotic speaker cables. In my opinion, there is little difference, they're both voodoo.

There are two reliable ways to know if you must replace a cap, look at it and measure it. 1) A failed NPE cap may or may not burst or leak. Se the photos on Wikipedia, Capacitor plague. (None of these photos show NPE caps from an a passive audio crossover.)
1565194378768.png


1565194443612.png


2) The way to know for certain if a cap has gone out of spec is to measure it. This requires an LC meter, such as this inexpensive one, and knowing what the intended capacitance was. To use one of these inexpensive meters, you must cut the leads of the cap. I'm told there are other meters called ESR Capacitance meters that allow testing while the cap remains connected to the crossover. They may be more expensive.
I must say it would take a lot of concentration, can't find anything wrong with the sound, but I think my ears are even more easily fooled than average.
It's not easy to tell just by listening.
 
killdozzer

killdozzer

Audioholic Field Marshall
@Swerd :D I admit it, I WAS trying to see if I can go without opening the speaker, but you made it really clear. Thank you for that. I would probably prefer the other answer, but...
 
Last edited:
highfigh

highfigh

Audioholic Overlord
As long as you have a supply of suitable replacement vacuum tubes, you'll be OK. Be sure to readjust the bias occasionally.
Some designs balance the bias, but that doesn't determine the bias- it makes swapping tubes easier and less 'techy'. As far as quantity, I think I'm pretty well set, after the last rummage sale.
 
killdozzer

killdozzer

Audioholic Field Marshall
This is a great read, without a doubt. Midway, I remembered you already gave me this link long time ago. Someone more knowledgeable would probably be able to deduce indirectly, what to expect with XO parts losing their properties, but I can’t for most part. I read it again and it explains a lot on XOs, but very little on old, dried or otherwise compromised parts.

I was hoping for something more straightforward. You know those elements that look like blue M&M’s:

1565340137492.png


Having one of those detach in my Philips DVD player made the sound look like a poorly picked up radio station. A lot of noise and static. (Disk drawer also failed, so I tossed it, the one I posted pics in AH long time ago) When the same thing happened in one of these old reporters’ VHS Canon’s;
1565340196478.png


the picture had a lot of static, lost colour and had these stripes over:
1565340250105.png

You could see the pic but with static. Once reatached, the problems were gone. I was hoping for something like that; knowing from the way they perform if anything's wrong.



It would seem that opening them and testing the XO is the only way to know for sure.
 
highfigh

highfigh

Audioholic Overlord
This is a great read, without a doubt. Midway, I remembered you already gave me this link long time ago. Someone more knowledgeable would probably be able to deduce indirectly, what to expect with XO parts losing their properties, but I can’t for most part. I read it again and it explains a lot on XOs, but very little on old, dried or otherwise compromised parts.

I was hoping for something more straightforward. You know those elements that look like blue M&M’s:

View attachment 30468

Having one of those detach in my Philips DVD player made the sound look like a poorly picked up radio station. A lot of noise and static. (Disk drawer also failed, so I tossed it, the one I posted pics in AH long time ago) When the same thing happened in one of these old reporters’ VHS Canon’s;


the picture had a lot of static, lost colour and had these stripes over:

You could see the pic but with static. Once reatached, the problems were gone. I was hoping for something like that; knowing from the way they perform if anything's wrong.

It would seem that opening them and testing the XO is the only way to know for sure.
The blue components are called 'disc capacitors'- that type isn't used for crossovers.

What speakers might need crossover help and what are you hearing/not hearing that makes you think they need to be serviced?
 
killdozzer

killdozzer

Audioholic Field Marshall
The blue components are called 'disc capacitors'- that type isn't used for crossovers.

What speakers might need crossover help and what are you hearing/not hearing that makes you think they need to be serviced?
Thank you very much. That was just an example of a situation where you could suspect something is wrong before opening the damn thing. :)

I'm just trying to learn how and if it's possible to tell whether your speakers need any refreshing without opening them. It would seem not.

I'm asking for my B&W 802 S1. I'm still not sure it is necessary. I want to find out whether it is.
 
highfigh

highfigh

Audioholic Overlord
Thank you very much. That was just an example of a situation where you could suspect something is wrong before opening the damn thing. :)

I'm just trying to learn how and if it's possible to tell whether your speakers need any refreshing without opening them. It would seem not.

I'm asking for my B&W 802 S1. I'm still not sure it is necessary. I want to find out whether it is.
How old are they? If they're less than 20 years old and haven't been exposed to much more than 50W (or 100, if designed for more), I doubt they need anything. I have a 40 year old pair of Jamo speakers that sound great and I haven't replaced anything in the crossovers.
 
killdozzer

killdozzer

Audioholic Field Marshall
History of B&W says 1987, this is the XO:
1565426007140.png

I can't tell what they've been exposed to. I suspect they changed a few owners. My father had them on solid 150 but he never liked music loud.
 
highfigh

highfigh

Audioholic Overlord
History of B&W says 1987, this is the XO:
View attachment 30492

I can't tell what they've been exposed to. I suspect they changed a few owners. My father had them on solid 150 but he never liked music loud.
I found some photos of B&W 802 crossovers- may or may not be the same as yours but I'm not sure I would blindly change parts without testing for the before/after response. I might consider changing the blue caps for something "better", but if they sound good, I would probably leave them- the caps are rated for 70WV, which is a lot more power than they're ever likely to see.
 
killdozzer

killdozzer

Audioholic Field Marshall
I found some photos of B&W 802 crossovers- may or may not be the same as yours but I'm not sure I would blindly change parts without testing for the before/after response. I might consider changing the blue caps for something "better", but if they sound good, I would probably leave them- the caps are rated for 70WV, which is a lot more power than they're ever likely to see.
The attached photo is from the brochure that TLS Guy sent me, it is the exact model I have. Thanks again.
 
highfigh

highfigh

Audioholic Overlord
The attached photo is from the brochure that TLS Guy sent me, it is the exact model I have. Thanks again.
Might not be a bad idea to check the caps to see if they have drifted but they probably wouldn't use inferior components, so even that might warrant communicating with B&W (or maybe a B&W user group to find out who has done this with good results).
 

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