Do 30 year old home speakers need their caps replaced?

[pbman1953]

I have home speaker pair from Ken Forsyth, EAW (Eastern Acoustic Works)that over 39 years old. My question if you feel that the crossover caps should be replaced? I doubt any of the coils would go bad , or would they?
 

[acheld]

Ahhh, that's like waving a red flag in front of a bull!   

Not really familiar with EAW speakers . . .

IF these are passive speakers:

I probably would replace electrolytic caps based on their age (this is because I can do this, not because it's the right thing); film caps, leave alone.   But, in general I think caps in speakers are not stressed much and a better approach would be to:

1.  Listen.  If the speakers don't sound right, proceed - 
2.  Inspect.   Leaking or bulging electrolytic caps.
3.  Measure.  ESR and capacitance preferably out of circuit.


If yours are active, then I'd probably replace electrolytics based on age alone. 

[pbman1953]

Thanks!


I'll check them out but they are all non-polar electrolytics

[acheld]

Well it looks you've done the hard work (I hate the pink stuff!), so measuring ESR and capacitance would be reasonable to do.  If it ain't broke, don't fix.   That's a hard rule for me to follow, but it is the right approach.

Those non-polar caps are not easy to find these days.   I wonder what film caps would sound like.  (I'm not recommending them but just curious).

[pbman1953]

No problem finding them, Parts Express

[pbman1953]

The 16uf's came out to 20uf


The 4's to 6uf


EAW is Eastern Acoustic Works


A pro sound company company that you'd see their speaker array's  at large venue concerts


Ken Started in home audio first

[jjasilli]

If you're into it, sound quality might be improved by replacing the caps & resistors with audio grade components.

[pbman1953]

Please tell me which ones,


Polyester  or Polypro




thanks

[acheld]

In general, polypropylene is the preferred dielectric.   

How much "hearable" difference it makes in an audio crossover network is debatable.

But I personally try to use polypropylene whenever I can.   

I'm a big fan of film caps over electrolytics whenever it is possible.  In my guitar amp power supplies, I use film caps for any value 40uF or less; they are (nearly) bullet proof until someone who will be nameless sets one up on a fence behind his house.   

[jjasilli]

The best bang for the buck is to swap in plastic caps in place of electrolytics.  Electrolytics are the worst choice in the signal path; they are used by manufactures only because they are cheap.  Use audio grade caps of the same mF value and at least the same voltage rating.  Cap prices can range from under $1 to well over $300 each!  There are diminishing returns.  Probably, a $300 cap does not sound 3X better than a $100 cap.  If there are electrolytics used in parallel, this was probably done to reduce ESR.  ESR is the internal, unwanted resistance of the cap.  So, 2 caps in parallel will have only 1/2 of the unwanted ESR.  Plastic caps have less ESR.  The point is: you might be able to reduce the # of replacement plastic caps.  Here's a page from Parts Express that lists mid-price caps:  https://www.parts-express.com/search?order=base_price:desc&page=3&keywords=capacitor


Next is audio grade resistors in place of the cement blocks.   See:  https://www.parts-express.com/search?order=base_price:desc&keywords=resistor


The inductors can also be replaced; but this requires more expertise and gets deep into the weeds.  You can also google diy mods for your speaker crossovers.


EDIT: Another thing - sometimes cheap, thin wire was run from the cross-over to the speaker drivers.  This can be improved with decent gauge lamp cord or speaker wire.  Be sure to maintain the existing polarity on each driver.  (Sometimes a driver's wired polarity is reversed on purpose.)

Have fun with your project!