I bought a couple of capacitors from Radioshack to use as bass blockers for my speakers but I'm not sure if they will work. Does anyone know if they need to be non-polarized? I always thought that speakers are DC current and these would work but I read online that they need to be non polarized. Also, I bought a pair of 220uf for my front Kicker 6.5"s, will that be a good cutoff point?
Thanks for the help.

220µF 35V 20% Axial-Lead Electrolytic Capacitor - RadioShack.com