Aging of capacitors within crossover networks

"'passive'-component values in crossovers is highly overrated IMO"

Disagree. Small changes here can make huge changes in sound.

"caps, resistors, and inductors in crossovers are of a + or -10% tolerance from the beginning, and some are + or - 20%"

You don't think the person building the crossover tests them all? Come on.

"Also understand that it takes doubling or having of a component's value to change its effect by one octave."

that depends on the crossover topology, not true in all cases, AFAIk.

"Replace with higher-quality parts for better sound? "

Maybe, maybe not. doing so presumes you know more about the parts/sound/speaker/crossover than the designer, which I find is not often the case. Parts usually were chosen for a reason, and that is not always price.

"Axon 'propylenes without any bypasses" - which is not a bad thing. Axon (aka Solen) is basically about the best film cap that can be had in larger values (say, over 10uf.) in the .1-1uf range there are lots of choices however.

Regarding caps degrading - its' mostly electrolytic types that have this problem, and then usually in stuff that runs higher voltage than speakers. (e.g. amps, power supply bypass, etc.) IN that case, replacing elytics is a good idea. Even better is getting rid of them entirely and replacing with oil or film caps.

-Ed

"You don't think the person building the crossover tests them all? Come on."

Ed, YOU and I might measure them, but do you really think manufacturers of even expensive speakers measure and select every cap, resistor, and inductor that goes into their crossovers? "Come on" yourself. Maybe SOME of them might measure to see if they're close, but in anything less than the most-expensive speakers, that stuff gets installed exactly as it comes from the supplier, without selection. That happens because it makes virtually NO difference to the performance of the crossover whether, for instance, that hi-pass cap's -3dB point is 2.8KHz or 2.9KHz or 3KHz or 3.1KHz or... Plus or minus 10% is less than an eighth of an octave, and only the most-skilled listener could hear the difference, and only God knows what's correct.

I agree that Axon/Solen/SCR 'propylenes are quite-decent-sounding caps and probably the best dollar values in caps over maybe 10uFs, but even this tinned-eared audiofool can hear the improvement even in the midrange when they're bypassed with, for instance, a North Creek Harmony 0.22/625, and then more improvement when they're replaced with bypassed large-value NC 'propylenes.

Aerial's VP of marketing actually had the nerve to tell me that they built their crossovers with the best-sounding parts available. I almost laughed in his face.

And you're right about changing values depending on the filter topology--I was generalizing about a 1st-order filter. In higher-order filters, changing a value by double or half makes LESS than an octave difference.

I'm firmly in the camp that believes that manufacturers pick the best parts they can find FOR THE PRICE and that it's easy for us audiofools to find better-sounding parts.
.

"You don't think the person building the crossover tests them all? This reflects the old fashoned way of thinking about quality control tests.

The modern approach is that the output of a production process is monitored by testing a sample of what is being produced. The test results are used, not to verify that the tested items are good, but to detect if the production process is correct. If tested samples fail, the production process is fixed. After doing this for a while all the output is good, and does not require testing. Quality of the product depends on the production process, not on testing. A small percentage of the output continues to be tested, but only to detect if something goes wrong with the process.

From personal experience, I recommend that drivers need new suspensions after 6 or 7 years. Despite their looking fine, I was shocked to find mine COMPLETELY deteriorated. The improvement in sonics via slam, immediacy, bass, and naturalness was astonishing. This is far more critical than capacitor aging.

The premise that

more expensive = better sound

or

more botiquey = better sound

is what I find to be a fallacy. Sometimes it's true, sometimes its' not. Unless you try every reasonable value of every type cap in a particular application, there can be no conclusions drawn one way or another. IMHO, the manufacturer is a lot more likely to have done experiments like that than any end user is likely to do.

most expensive parts do not equal necessarily better sound. Case in point re: caps - I'd take a vintage (read: cheap-ass $2 or so) paper-in-oil cap over ANYTHING made by Blackgate, for values where it's appropriate (mostly power supply stuff). there couldnt' be a greater difference in price vs. hype vs. quality of sound. The cheap ugly oil cap sounds and performs way better than the overrated Elytic.

-Ed