Bypassing Caps - what is it really about?


I understand the theory, but I've never been clear on the practice. 

Some say its to extend the highs, but I see people using stuffy vintage caps as their bypass. I've also seen people bypass incredibly good existing caps with more, like Dueland on top of Dueland. So what is this really about? Is it about mixing tones of the capacitors?

 

clustrocasual

See that’s your problem right there. You confuse $40 in parts and a weekend with experience. I have been designing speakers for professional applications for the better part of 2 decades. When you lack experience, you may be able to convince yourself with $40 in parts and a weekend that bypassing a capacitor that is ideal up to nearly a MHz provides some benefit other than just changing the total value. I don’t have such a luxury.

Pick a large respectable high end speaker manufacturer. Magico, B&W (high end), Wilson. Do they bypass their large capacitors with much smaller ones? No. Could they afford it? At those margins, of course, small capacitors are inexpensive. Why don’t they? It will have no benefit. Do you honestly believe these companies don’t know any better?

My comment is specifically about crossovers. I will leave power supplies to those that know better, and the same for capacitors passing audio signals in amplifiers and other electronics.

That’s your problem right there. Research without experience. $40 in parts and a weekend is worth more than all of the Internet.

I can see a stuffy sounding vintage cap with poor high frequency transparency being bypassed by one that does to create some layering (?).

But that could create some weird situations - imagine caps which image poorly with a very mono sound, being bypassed in the high freq with a high fidelity cap. So the high frequencies image 3d dimensionally on top of an old low fi midrange? Or is that effect the goal? It could be interesting....?? 

When you lack experience, you may be able to convince yourself with $40 in parts and a weekend that bypassing a capacitor that is ideal up to nearly a MHz provides some bene

When you lack an open mind you may be able to convince yourself your measurements and models are always adequate.

Takes an open mind and discerning ear to realize when one or the other has fallen short, and this topic is impossible to argue online.  That's why I make suggestions to audiogoners to experiment inexpensively and come to their own conclusions.  Or they can listen to you stroke your beard and tell us nothing is left to be learned.

@clustrocasual ,

If you means capacitors passing signals in electronics maybe there are some effects. In speakers though, you have to look at the combined effect of the capacitor and driver. If I bypass a 100uF (was mentioned above) electrolytic with a 1uF, there is no benefit because where the 1uF starts to provide any benefit, the driver has no output.

Oh come on. Do you think with million dollar development budgets that we never listened to anything?  What do you think companies who develop speakers do? Listening confirms measurements and measuring confirms listening. It is always a two way street.  Your "stroke your beard" comment is out of line. Just experiment sounds simple, but if you don't understand the basics, like how capacitors perform in a crossover, you are likely to make a flawed experiment and convince yourself of something incorrect. Then you will come on here and tell others about it like it was true.

There is lots still to learn. How to interpret the electrical characteristics of a capacitor and apply that to a crossover is not one of them. There are parameters of different capacitor constructions that some believe are audible. Dielectric absorption already mentioned and mechanical resonances being two, electrical resonance potentially being a 3rd influenced by ESR in the operating range a 4th. A small bypass capacitor will not solve any of those issues, nor make any change that is not swamped by component to component variation.

Do you really think these high end speaker companies have never thought of bypassing large capacitors with a much smaller one to make a better speaker?

 

When you lack an open mind you may be able to convince yourself your measurements and models are always adequate.

Takes an open mind and discerning ear to realize when one or the other has fallen short, and this topic is impossible to argue online.  That's why I make suggestions to audiogoners to experiment inexpensively and come to their own conclusions.  Or they can listen to you stroke your beard and tell us nothing is left to be learned.