Bi-polar vs poly caps. in xo .

marchel

Member
2007-11-18 4:51 am
Dear All,

Is it ok to use bipolar caps on non important part of the XO, such as zobel network, trap circuit, notch filter and capacitor part of a 2nd order lowpass filter in woofers?

Are there any disadvantage of using bipolar caps instead of poly caps when only used as described in the first paragraph of this post?

Thank you.
 
They are OK for non- or less-than-critical areas.

Advantages: Smaller size and price

Disadvantages: shorter lifespan, higher value errors (~10% plus), and increasing value degradation over the lifespan.

They are often used where large values are required, for the advantages listed above, but poly caps, so far as I know, are never inappropriate anywhere in a crossover.

If your budget is the limiting factor put the lion's share of it into the drivers and compromise in the crossover if you must. Maybe replace with polys later when you can afford them, especially if you intend to keep your speakers for some time.

There is much debate about audible differences, but I would venture to say that the tighter tolerances of poly caps will ensure you are shaping the sound the way your design actually calls for.
 

marchel

Member
2007-11-18 4:51 am
My project calls for 30 and 25uf caps. And yes my budget is limited, I think I'll initially use bi polar caps as I already have them from past projects , and then upgrade later.

I've spent the lion's share on drivers from my budget, Good suggestion .

Thank you.

BTW, I'll be using peerless hds tweeter and 7" hds woofer for my 2.5 way project.