Bypassing capacitors

[davidlzimmer]

I have searched but just couldn't find the info I need.

Can some one explain the art of bypassing capacitors in a crossover.

A link to a tutorial would be nice.

Thanks!

 

[GM]

Greets!

No link or time for a tutorial, but 'in a nutshell', a capacitor has inductance and resistance, so when highpassing a wide BW you can shape its response by paralleling different values.

GM

 

[RJ]

Hi Dave,
Rudy J. here...
Here's some very good links;
http://www.northcreekmusic.com/Bypassing.html
http://www.htguide.com/forum/showthread.php4?t=20346
http://www.humblehomemadehifi.com/Cap.html
RAW Acoustics version using Sonicaps;

http://www.soniccraft.com/sonicap_platinum.htm
http://www.e-speakers.com/catalog/claritycap_sa_range_4272430.htm

 

[auplater]

Links

Some of those links are little more than advertisements disguised as "technical" papers. At least ThomasW on HTforum states a rational approach... minimize costs and esr for a given capacitance... that makes sense.

If you'd like to send me LOTS of money, I can prolly scare up some mellifluent hyperbolic bloviation to improve the sonic character you perceive when listening and building your speakers.

otherwise, find some decent poly caps (avoid electrolytics) and build up a parallel stack to your desired value, and enjoy the change you put back in your pocket by avoiding $$$$ "boutique" capacitors.

auplater

 

[davidlzimmer]

Ok guys thanks!

Is the general idea to parallel small (less expensive) to total up to a larger (more expensive) and get the same value with less resistance?

Is the idea more to save money or to get less resistance or what?

 

[davidlzimmer]

bloviation!!!!

On this forum? Never!!!!!!! ''

 

[poobah]

Is the idea more to save money or to get less resistance or what?

Yes!

 

[davidlzimmer]

When the Poobah says yes, I guess I've got it!

Thanks all.

Rudy, I guess you know what project I'm working on!

 

[poobah]

Simmer down!

Actually Dave, it is a pretty big topic. When you actually get to a design, post, and people will help.

You do need to spend some money on big caps sometimes... but that is because they are big... you can safely stay away from the fancy stuff until you (or anyone else for that matter) actually know better.

 

[davidlzimmer]

Is it an unwritten law to stay away from non-polarized electrolytics,
or can they be used with a quality bypass?

 

[poobah]

That could probably start a fistfight 'round here. Most would say that films are far better. That is not to say some fine x-overs haven't been built with electrolytics.

 

[davidlzimmer]

I'll just go with the "most". Don't want to start any wars''

 

[Badge]

Ok, let me fan the flames. The Blackgate AC rated non polarized caps are the finest caps I have used in speaker crossovers. They are more organic and yet detailed. I have tried many different flavors of film caps and the Blackgates are better IMO.

 

[RJ]

As ThomasW says....
http://www.htguide.com/forum/showthread.php4?t=20346

We frequently make very large cluster caps using multiple smaller value units. The benefit of doing this is lower cost and a very low ESR.

The GE caps in ThomasW's picture are from Madisound;
http://www.madisound.com/cgi-bin/index.cgi?exact_match=yes&product=GE&cart_id=7803783.20348
I switched from using Electrolytics and am using a combination of GE's and Carli Mylars;
http://www.madisound.com/cgi-bin/index.cgi?exact_match=yes&product=CA&cart_id=7803783.20348
Along with the buyouts;
http://www.madisound.com/cgi-bin/index.cgi?exact_match=yes&product=SU&cart_id=7803783.20348

Those Blackgate caps are expensive!
http://www.kyoto-electro.com/nx.html
Is there a cheaper supplier???