How much does speaker performance degrade over time?

[techsamurai]

I own speakers that are pretty old - some are 25 years old and the newest one is perhaps 20 almost

What parts degrade?

I know the foam surrounds will go first. In fact, the foam surrounds on my speakers cracked and I replaced them with new drivers from B&W. The surrounds on the ones I have not replaced seem a bit less flexible - I think the gray foam is more prone to rot than the black one.

I know electrolytic caps can also degrade over time but I'm not sure my speakers have them in their crossover.

What else can go bad? Drivers generate heat (didn't know that until recently)- do bass drivers get bad over time?

And when do you decide to upgrade? I was watching a review of a speaker from the same series that's 20+ years old and it was holding its own against newer KEF models.

Should I just replace all the existing midrange drivers?

 

[levimax]

I own speakers that are pretty old - some are 25 years old and the newest one is perhaps 20 almost

What parts degrade?

I know the foam surrounds will go first. In fact, the foam surrounds on my speakers cracked and I replaced them with new drivers from B&W. The surrounds on the ones I have not replaced seem a bit less flexible - I think the gray foam is more prone to rot than the black one.

I know electrolytic caps can also degrade over time but I'm not sure my speakers have them in their crossover.

What else can go bad? Drivers generate heat (didn't know that until recently)- do bass drivers get bad over time?

And when do you decide to upgrade? I was watching a review of a speaker from the same series that's 20+ years old and it was holding its own against newer KEF models.

Should I just replace all the existing midrange drivers?

The most common issues are surround deterioration and tweeter ferro fluid drying out. I have had several tweeters dry out with big response changes. Check out this thread https://www.audiosciencereview.com/forum/index.php?threads/tweeter-expiration-date.64151/

 

[techsamurai]

The most common issues are surround deterioration and tweeter ferro fluid drying out. I have had several tweeters dry out with big response changes. Check out this thread https://www.audiosciencereview.com/forum/index.php?threads/tweeter-expiration-date.64151/

Oh, that's not good... How will deterioration manifest? I can go look at REW measurements or take some. Is there a phone app that can do that so I don't need to do a whole set up with Umik-1 and all?

I'm pretty sure there are no tweeters left for any of my speakers... I was checking the parts.

 

[levimax]

Oh, that's not good... How will deterioration manifest? I can go look at REW measurements or take some. Is there a phone app that can do that so I don't need to do a whole set up with Umik-1 and all?

I'm pretty sure there are no tweeters left for any of my speakers... I was checking the parts.

I believe there are some phone apps but I have not used any, maybe someone else can recommend something. I use a MIC and REW free software which is a great tool to have for playing around with speakers and also for room corrections. See below 2 examples of how the response changes between a new and dried out ferrofluid tweeter. Not all tweeters have ferrofluid so you need determine that first.

 

[techsamurai]

I believe there are some phone apps but I have not used any, maybe someone else can recommend something. I use a MIC and REW free software which is a great tool to have for playing around with speakers and also for room corrections. See below 2 examples of how the response changes between a new and dried out ferrofluid tweeter. Not all tweeters have ferrofluid so you need determine that first.

View attachment 509349

View attachment 509350

Thank you, I checked and it seems that the speakers did have ferrofluid.

 

[SHB]

The other two things that will change will be the compliance of the woofer spider and the capacitors in the crossover.

The spider can’t be replaced, but it just loses its “springiness”. Not a huge deal, but that changes the sound of the speaker a small bit.

As mentioned, The capacitors in the XO will change value as they age. This will change the crossover values. How much will depend upon the type.

Basically, you ride them till they die when they’re that old.

 

[techsamurai]

The other two things that will change will be the compliance of the woofer spider and the capacitors in the crossover.

The spider can’t be replaced, but it just loses its “springiness”. Not a huge deal, but that changes the sound of the speaker a small bit.

As mentioned, The capacitors in the XO will change value as they age. This will change the crossover values. How much will depend upon the type.

Basically, you ride them till they die when they’re that old.

Looking at the inside of the higher model in the series, I'm sure most of my speakers have film capacitors, not electrolytic capacitors which last longer.

I hope the better speakers have electrolytic ones but that would also mean they degrade faster.

Will that be apparent in measurements?

 

[levimax]

Looking at the inside of the higher model in the series, I'm sure most of my speakers have film capacitors, not electrolytic capacitors which last longer.

I hope the better speakers have electrolytic ones but that would also mean they degrade faster.

Will that be apparent in measurements?

In general film caps in a passive crossover will last indefinately, even electrolytics can last a very long time, heat is what kills them and compared to a power amp a passive crossovers run very cool.

 

[SHB]

Looking at the inside of the higher model in the series, I'm sure most of my speakers have film capacitors, not electrolytic capacitors which last longer.

I hope the better speakers have electrolytic ones but that would also mean they degrade faster.

Will that be apparent in measurements?

My thought is that with 20-25yo speakers, who knows what type of caps are in the XO?

 

[techsamurai]

My thought is that with 20-25yo speakers, who knows what type of caps are in the XO?

There are plenty of videos of folks taking apart the speakers in the lines. They use polyester film caps (not polypropylene). There are a couple of air core inductors and Suncast resistors. If I knew how to solder and knew what parts to replace them with, I wouldn't mind getting much more expensive parts and spending $100 per speaker.

 

[voodooless]

Thank you, I checked and it seems that the speakers did have ferrofluid.

Note: ferrofluid isn’t just one single substance. There are multiple types and they improved over the years. In older speakers the kind of ferrofluid is quite prone to drying out. Nowadays the more modern substances do not dry out as much anymore.

 

[mhardy6647]

Crossovers: L, C, and R. As long as the proper values are in place in the crossover, all will be well. The signal cannot tell what dielectric is between the capacitor's plates, but it can "tell" the C and R of the capacitor.
$100 won't get you too far in the boutique crossover component marketplace.

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As to the mechanical -- other than the sensitivity of certain magnetic materials (traditionally, AlNiCo) to mechanical shock and time-dependent "discharging" (loss of magnetic field strength), and the issue of unstable materials used for spiders or (more typically) surrounds, drivers can last many decades without needing rehabilitation (and if not grossly abused).

I have a friend whose main loudspeakers are anchored by an octet of RCA field coil drivers (woofers) that are all more than 80 years old. They're also outstanding drivers, quantitatively & qualitatively -- as befits what were, in practice, state of the art and cost no object products.

 

[Ktacos]

The other two things that will change will be the compliance of the woofer spider and the capacitors in the crossover.

The spider can’t be replaced, but it just loses its “springiness”. Not a huge deal, but that changes the sound of the speaker a small bit.

As mentioned, The capacitors in the XO will change value as they age. This will change the crossover values. How much will depend upon the type.

Basically, you ride them till they die when they’re that old.

The cap age thing seems to maybe not be so true. Nearly 40 year old caps tested here.

Capacitor upgrade in crossover - Is it audible? - Part 2

Here is the second part on the topic "Capacitor upgrade in crossover - Is it audible? This time it is exclusively about the measurable differences of electrolytic capacitors with film capacitors in crossovers of loudspeakers. The first part about film capacitors can be found here and who likes...

www.audiosciencereview.com

 

[mhardy6647]

I forgot to add that AlNiCo magnets can be recharged. It is a Frankensteinian process.

 

[techsamurai]

I believe there are some phone apps but I have not used any, maybe someone else can recommend something. I use a MIC and REW free software which is a great tool to have for playing around with speakers and also for room corrections. See below 2 examples of how the response changes between a new and dried out ferrofluid tweeter. Not all tweeters have ferrofluid so you need determine that first.

View attachment 509349

View attachment 509350

I think the tweeters are still ok - I did some sine sweeps and listened to some 5-channel stereo, got close to every speaker and the violins sounded the same. I'm playing low volumes to isolate each speaker so a drop-off of several db should be more obvious but it gets tough over 10KHz and I can't hear anything over 14KHz.

I'll listen to a few tweeter specific songs today like Pink Floyd's Time.

 

[techsamurai]

Crossovers: L, C, and R. As long as the proper values are in place in the crossover, all will be well. The signal cannot tell what dielectric is between the capacitor's plates, but it can "tell" the C and R of the capacitor.
$100 won't get you too far in the boutique crossover component marketplace.


I have a friend whose main loudspeakers are anchored by an octet of RCA field coil drivers (woofers) that are all more than 80 years old. They're also outstanding drivers, quantitatively & qualitatively -- as befits what were, in practice, state of the art and cost no object products.

Well, a youtuber did an upgrade of a JBL standmount crossover and swapped existing cheap parts with more expensive ones and the recording showed clear differences elevating the speaker that sounded quite muffled before that. He spent $100 for the main part and $72 for optional parts (less important).

I'm sure all my speakers have a second order crossover. I wouldn't mind spending a few hundred for my LR (as those could probably reach 800 level performance with that, if not better), possibly more and a few hundred for my center which probably has a few more parts in the crossover being a 2.5 way.

The surrounds just a couple of polycaps may do the trick but that might be overkill. I'd like to make the upgrade but I'm afraid of taking it apart

I do wonder how long they'll last. I didn't even know about the tweeter possibly having issues. I'm definitely considering replacing the main drivers in the remaining pair.

 

[mhardy6647]

XOs are generally very (very!) easy to rehab. Whether it's value added so to do is a matter of debate -- well, usually not, actually, but, e.g., very old bipolar (nonpolar) electrolytics can drift out of spec with age, and the tolerances were very wide for electrolytics 30 and 40 years ago.

Well, a youtuber did an upgrade of a JBL standmount crossover and swapped existing cheap parts with more expensive ones and the recording showed clear differences elevating the speaker that sounded quite muffled before that. He spent $100 for the main part and $72 for optional parts (less important).

So, this youtuber (sounds like a potato strain!) showed data, or just 'recordings'?
You, of course, are free to spend as much money as you want based on such recommendations.

 

[techsamurai]

XOs are generally very (very!) easy to rehab. Whether it's value added so to do is a matter of debate -- well, usually not, actually, but, e.g., very old bipolar (nonpolar) electrolytics can drift out of spec with age, and the tolerances were very wide for electrolytics 30 and 40 years ago.


So, this youtuber (sounds like a potato strain!) showed data, or just 'recordings'?
You, of course, are free to spend as much money as you want based on such recommendations.

So, switching the parts in the crossover from the cheap or "cheezy" parts does not always improve the sound?

 

[DanielT]

The most common issues are surround deterioration and tweeter ferro fluid drying out. I have had several tweeters dry out with big response changes. Check out this thread https://www.audiosciencereview.com/forum/index.php?threads/tweeter-expiration-date.64151/

This issue with dried ferrofluid is the biggest reason why I don't buy and test older speakers anymore. Feels like a lottery.

AI, even if you can't automatically assume that it's true, can, if you're lucky, provide insight into whether a specific speaker brand/model has ferrofluid in the tweeter or not. Here are two examples taken at random:

In the case of the JPW P1, I would have invested in two new replacement tweeters for around $40 a pair.

 

[wwenze]

Oh, that's not good... How will deterioration manifest? I can go look at REW measurements or take some. Is there a phone app that can do that so I don't need to do a whole set up with Umik-1 and all?

I'm pretty sure there are no tweeters left for any of my speakers... I was checking the parts.

At low volumes the distortion should be way below measurable, or, say, -60dB from the signal. At higher volumes, refer to Amir's measurements, I guess.

By the time you can see the FR change, the distortion would have crossed -40dB. Or it can also cross -40dB without FR change. Either way, distortion is the easiest way to measure for changes in performance. For the drivers, anyway.

Blown capacitor, now that can change FR with or without distortion. And it was a good film stuff inside a Monitor Audio speaker too.