Good idea to update my speaker crossover/capacitors? (They're well over 20 yrs old)

[Seize]

So I've been doing a bit of research on the subject. What I'm lead to believe is that if you've got some speakers that around 20 yrs or older that it's good practice to change out the capacitors and associated parts.

Here's a pic of what my crossover looks like.

Is the large white rectangular box located on the bottom left a resistor as well? What about the large gray foam cylinder, what is that?

Please excuse my ignorance, I'm a total novice here.

 

[Swerd]

Because you're a total novice, I'll give you the straight forward answer first:

If it ain't broke, don't fix it.​

If you do have evidence the crossover is not working as designed, please tell us.

Much of the internet-based "wisdom" about replacing old capacitors comes from the fact that the large power supply capacitors of amplifiers have been known to fail after aging. But these capacitors perform a very different function than the much smaller filter capacitors in speaker crossovers.

So the often repeated but untrue advice of replacing the capacitors in old crossovers is hearsay and should be ignored, unless you have other good reasons that the capacitors have failed.

The large white box in your photo may be a capacitor, but I'm not familiar with it. It's label, 6.8 J 100 may mean 6.8 µF 100 volts, but I can't say that for certain. (µF stands for microFarad) Maybe someone else can confirm or correct that.

The other component that is definitely a capacitor is the gold colored cylinder labled 22 µF 23 VAC Bipolar ±5%. That is a small inexpensive non-polar electrolytic capacitor with a value of 22 µF and rated to AC voltage as high as 23 volts. Others may suggest that you replace that with a 22 µF capacitor with a higher VAC rating such as 100 or 250 volts, and made with metalized polypropylene. Although that would be a more robust and stable cap that can sustain higher voltages before thermal failure, it will be larger in size than the existing cap and is unlikely to fit on your crossover board. So I would leave it as is until you have clear evidence that it isn't working.

I don't know what the gray foam covered cylinder is.

 

[Irvrobinson]

Much of the internet-based "wisdom" about replacing old capacitors comes from the fact that the large power supply capacitors of amplifiers have been known to fail after aging. But these capacitors perform a very different function than the much smaller filter capacitors in speaker crossovers.

So the often repeated but untrue advice of replacing the capacitors in old crossovers is hearsay and should be ignored, unless you have other good reasons that the capacitors have failed.

Swerd is correct. Capacitors in the crossovers of consumer speakers usually operate at such a low voltage and low temperature that their lifespan is probably not much different than what the capacitor's lifespan would be just sitting on a shelf. That isn't to say a crossover cap can't fail, but when you look at caps that degrade or fail they're usually in products with high temperature or lots of volts in proportion to their rating, or both.

 

[Seize]

Thanks for the insight and information, guys. I really am learning alot here. As far as the x-over not functionally properly, I'm not sure. I bought the speakers (MB Quart 280's) second hand from a fella who upgraded to some B&W 800's. So I really don't know how they sounded originally. I mean, as it stands right now, I think they sound good for the $60 bucks I paid for them

As far as me tinkering around with the x-over, I think when I get some free time I'll go ahead and do it. Not for the sake that I think it's going to change the sound. More because I'm a DIY type of guy, the parts are relatively cheap and well, the thought of me building my first crossover sounds kind of fun.

Anyhow, thanks again for the input. It's very much appreciated.

 

[Swerd]

Thanks for the insight and information, guys. I really am learning alot here. As far as the x-over not functionally properly, I'm not sure. I bought the speakers (MB Quart 280's) second hand from a fella who upgraded to some B&W 800's. So I really don't know how they sounded originally. I mean, as it stands right now, I think they sound good for the $60 bucks I paid for them

As far as me tinkering around with the x-over, I think when I get some free time I'll go ahead and do it. Not for the sake that I think it's going to change the sound. More because I'm a DIY type of guy, the parts are relatively cheap and well, the thought of me building my first crossover sounds kind of fun.

Anyhow, thanks again for the input. It's very much appreciated.

Go ahead, have fun and tinker.

If you want to get into this, a hand held LCR meter such as this, is worth having for a quick way to measure inductance (L) and capacitance (C). Most cheaper hand held meters measure voltage and resistance, but you will need one that also measures L and C.

 

[Damn Noise!]

I just did mine in my Infinity sm-152 speakers, it was a challenge but I got it done.
The new caps were HUGE! and I had to solder extension wire to them so I could relocate them...kind of a pain but glad I did it.
Sorry I didn't take any pictures, but so far so good!
A bunch of great videos on youtube about the proper way to desolder and prep areas to re-solder. I found the desoldering braids to work well.
If you take your time they will turn out great. Good luck!