Capacitor Size

my objective:

remove the low frequencies from my 6x9's, and keep the mid and high frequencies.

the guy at the install shop said go to Radio Shack and get-----130  micro feretz(spelling) capacitor.

is this the right rating?

also, the closest i could find to the rating was 100 or 220  micro fetetz would one of these do.

please help i am almost finished my sub box and ready to go, the fat lady is getting ready to sing

thanks

KINGPIN

OK, a couple of things here.  First, the suggestion of using a 130 micro-farad capacitor will create a 6db/octave crossover at about 320Hz assuming your 6X9's are 4-ohm speakers.  Products like this, by the way, are also called "bass blockers."  320Hz is quite high, but it will indeed keep the bass out of your speakers.  100 µfd will cross at  about 400Hz and 220 µfd will cross at about 200Hz.  I'd suggest using a crossover point of 200Hz.

You can use THIS chart, by the way, to see the effect of different crossover components.

Also, you cannot just go to Radio Shack and get any old capacitor.  You need a "non-polarized" capacitor rated for at least 100 volts or higher (depending on your amplifier wattage.)  I suggest purchasing caps designed for use in crossover networks, like these.