Capacitors and Inductors and Bears....oh my!

[Bruce Weldy]

I’ve always bought my crossover components from Speakerhardware.com, so I’ve never worried about trying to source them elsewhere. However, I might be making some changes where I just need some components and I’m struggling with the verbiage in the plans and what I’m finding available.

The inductors aren’t a problem as they are pretty straightforward, but the capacitors are a bit of the head scratcher…..

The plans show a picture of, and describe, an electrolytic cap and a poly cap. The 2k high-pass filter plan says the cap must be a poly or mylar with at least a 100V rating. However, the 1.2k plan says nothing about electrolytic, poly, or mylar and doesn’t discuss minimum voltage.

Parts Express sells a myriad of caps, but finding the ones that match are hard without more explanation. The offer Metalized Poly caps and Non-Polarized Electrolytic caps. A 10uf cap ranges from 67 cents to almost 10 bucks depending on which one you choose. And the voltage ranges are from 100 to 800.

I don’t mind spending a little more for better components, but I just don’t know what I should buy.
It would be nice if the plans were a little more specific with the type and voltage for each component. Mine are from April 2015.

I know this has come up before, but I’ve been searching the forum but haven’t found anything.

So, for a 1.2k high pass filter –
- Are non-polarized caps ok?
- What is the minimum voltage?

Just really having a hard time wrapping my head around this as I really don’t know anything about capacitor types and values.

[Grant Bunter]

Mmmm,
Brown Bears.
No, Black ones.
Grizzly maybe...

I would be surprised to find the same conditions for the 2K crossover weren't the same for the 1.2K, so poly or mylar.
Get hold of Leland, I'm sure he is all over it...

[Bruce Weldy]

Mmmm,
Brown Bears.
No, Black ones.
Grizzly maybe...

I would be surprised to find the same conditions for the 2K crossover weren't the same for the 1.2K, so poly or mylar.
Get hold of Leland, I'm sure he is all over it...

The problem is that Part Express breaks 'em up into two categories - Metalized Polypropylene Crossover Capacitors and Non-Polarized Electrolytic Capacitors....the plans don't mentioned anything about non-polarized, but they are electrolytic.....so, can I use 'em? That's the question.....

I hate to pump Leland for info, then buy 'em somewhere else......

[Bill Fitzmaurice]

The same requirements for the 2kHz crossover apply to the 1.2kHz crossover.

[Bruce Weldy]

So, is the reference to electrolytic caps just boiler-plate in the general crossover info and they aren't actually used in any of the crossovers?

[Bill Fitzmaurice]

All low pass filters use non-polarized electrolytics. All high pass filters use polys or mylars. You could use polys in low pass, but they'll cost more and won't work any better. The difference between 2kHz and 1.2kHz filters is the component values, not the components used.

[Bruce Weldy]

All low pass filters use non-polarized electrolytics. All high pass filters use polys or mylars. You could use polys in low pass, but they'll cost more and won't work any better. The difference between 2kHz and 1.2kHz filters is the component values, not the components used.

That clears it up a lot!

thanks.....