What's Best in Crossover Capacitors

[ack]

Don, you are giving away all the secrets!

I addition to Don's suggestions, I would use two different values to make a larger one instead of two of the same value. Different values would sound different even if they total the same. If you can, model the capacitance, ESL and ESR to reduce the "wiggles" in the FR. That may have been why when you tried this on a tweeter with 3 or 4 caps, it sounded dead. The 3 or 4 you picked "clashed".

It's been quite a while, but I believe I was used different-value caps with that horrible result; then, when I switched to just two (still different), the result was much better. Frankly, I am kinda scared playing with separate value capacitors, due to lack of experience and background.

 

[fas42]

It's been quite a while, but I believe I was used different-value caps with that horrible result; then, when I switched to just two (still different), the result was much better. Frankly, I am kinda scared playing with separate value capacitors, due to lack of experience and background.

Sorry to disagree with Don and Gary, but I believe if you don't really understand the characteristics of a particular type of capacitor, then the strategy should be to space in value by no more than about 3, or by at least 50. So:

1u, 3.3u, 150u -- good
1u, 10u, 150u -- bad, or at least not as good by a big margin

Again, you may get away with it, but I wouldn't do it ...

Frank

 

[MylesBAstor]

New Duelands go on Cable Cooker tomorrow for a week. Frederik thinks that's long enough to get a good sense of what his caps sounds like. Finally, a way to break those pesky caps in!

 

[fas42]

New Duelands go on Cable Cooker tomorrow for a week. Frederik thinks that's long enough to get a good sense of what his caps sounds like. Finally, a way to break those pesky caps in!

This cooking of cables and caps thing, this is all about materials having mechanical properties that affect electrical behaviour. Change the mechanical aspects, by whatever means, and you change the electrical characteristics by subtle but audible degrees.

The real headache is that no-one has a really decent handle on precisely what's happening; if you had that, you could do so much better in getting optimum behaviour always ...

Frank

 

[DonH50]

You really need to know the characteristics of the components... I have used RF caps with several decades of good response, and some power caps did good to reach even an octave (the latter were used in tuned RF amplifiers). Decoupling/power supply filter caps, especially large ones, tend to have low bandwidth, natch.

"Cooking" or running signals through a component can also do electrical things like fill traps and such, reducing hysteresis and lowering the noise floor. These are quite real, measurable effects but I am on record as questioning their audibility. Of course, that may simply prove my system and/or ears aren't good enough, the usual argument (that does not make it wrong, BTW, but I'm from Missouri so you have to "show me").

Honestly, I have put very little thought into why a capacitor in a crossover network (let alone a cable) should require extensive burn-in. I have read that numerous times; has anybody published reasons? Measurements? At this point I am just curious... - Don

 

[microstrip]

Honestly, I have put very little thought into why a capacitor in a crossover network (let alone a cable) should require extensive burn-in. I have read that numerous times; has anybody published reasons? Measurements? At this point I am just curious... - Don

Don,

I also have never read a reasonable reason why a decent polyester capacitor sounds different from an polystyrene one in a crossover. May be it is the same unknown explanation?
As you say, we can accept many obscure explanations for power decoupling or small signal capacitor behavior, but in such a limited bandwidth passive circuit it is even behind obscure.

 

[DonH50]

I'd have to dig for the articles and data, but there are articles about dielectric differences dealing with noise (traps, hysteresis), parasitics, leakage, tempcos, and all that between them, and among the others out there (ceramic, polypropylene, tantalum, etc.) It is pretty easy to measure some differences, but others, and in that application, I dunno'... Inductors can cause changes in the effective damping factor that are measurable and perhaps audible; as for capacitors, I suspect a lot of the differences heard are more related to a change in value (e.g. changing an older out-of-spec cap with a new in-spec one, or a new combination that yields a slightly different value than the original).

Another possibility is how the caps handle large signals; they do get nonlinear with large voltage/current. No idea if that is audible, or even to what degree it happens (let alone has been measured) for crossovers etc.

I wish I could remember the difference between polystyrene and polyester (etc.) -- might have to do some digging later. I know there is information out there, and I probably have some in the black hole cum file boxes in the basement.

 

[ack]

I found this white paper from ClarityCap on why capacitors sound different interesting...

And for reference purposes in this thread, I just scraped the following list off the humblehomemadehifi web site - it presumably represents the cream of the crop according to that popular site:

Amp Ohm FE-XAL-AL alu-foil / polyster in oil*
Audience Auricap MKP *
Clarity Cap MR *
Duelund VSF Cu-foil / paper *
Duelund CAST Cu-foil / paper in oil *
Intertechnik Audyn Cap Reference *
Jantzen Audio Superior Z-Cap *
Jupiter HT BeesWax *
Le Clanché PPM MKP *
Mundorf M-Cap 630VDC MKP *
Mundorf M-Cap Supreme Cap *
Mundorf M-Cap Supreme Silver/Oil *
Mundorf M-Cap Supreme Silver/Gold/Oil *
Obbligato Aluminium Foil *
Vishay MKP 1837 * (bypass)

 

[fas42]

Again, probably the best and most readable explanation of real capacitor behaviour was done by Ben Duncan as a series in HiFi News, starting in 1986: I've practically worn out the copies of those issues reading, and rereading what he said. You can probably still get copies of just those articles in hardcopy from the publishers, or Ben Duncan himself.

Frank

 

[MylesBAstor]

I found this white paper from ClarityCap on why capacitors sound different interesting...

And for reference purposes in this thread, I just scraped the following list off the humblehomemadehifi web site - it presumably represents the cream of the crop according to that popular site:

Amp Ohm FE-XAL-AL alu-foil / polyster in oil*
Audience Auricap MKP *
Clarity Cap MR *
Duelund VSF Cu-foil / paper *
Duelund CAST Cu-foil / paper in oil *
Intertechnik Audyn Cap Reference *
Jantzen Audio Superior Z-Cap *
Jupiter HT BeesWax *
Le Clanché PPM MKP *
Mundorf M-Cap 630VDC MKP *
Mundorf M-Cap Supreme Cap *
Mundorf M-Cap Supreme Silver/Oil *
Mundorf M-Cap Supreme Silver/Gold/Oil *
Obbligato Aluminium Foil *
Vishay MKP 1837 * (bypass)

Gotta give him an "A" for effort!

 

[ack]

Myles et al - a warm thanks to all for the advice... the project turned out to be a huge success; if in Boston, ping me! I also replaced the coils with Mundorf copper foils and that made a little difference, while the caps are responsible for a very considerable improvement...

How's the Duelund cooking going? Are you putting them in your CJ's?

 

[MylesBAstor]

Myles et al - a warm thanks to all for the advice... the project turned out to be a huge success; if in Boston, ping me! I also replaced the coils with Mundorf copper foils and that made a little difference, while the caps are responsible for a very considerable improvement...

How's the Duelund cooking going? Are you putting them in your CJ's?

Glad to read that it all came together. I haven't, unfortunately, had a chance to run the Duelands in yet. Too many things on my plate. When they go in, they'll be used in my King/Cello tape preamplifier. I'd have used
teflon but given the value needed, teflons would have cost me an arm and a wand.