What size capacitor should I use for my Dash tweeters to filter out bass?
91 Talon stock

Just a capacitor is not a very good filter at all(it will work , but doesn't offer much protection), anyway what cut off frequency do you want? or what size speakers are they going on? impedance of the speakers?

Lets say you want your cutoff freq to be 200 hz, since a cap is only a first order filter(6db per octave),Any freq at 100hz will be 6db quieter than at 200hz, and at 50hz will be 12db quieter than at 200hz.So as you can see you can still ruin your speakers pretty quick.The formula for first order high pass is...

Capacitor in microfarads = 1,000,000 / (6.283 x impedance in Ohms x cutoff in hz)

I have caps in the laser, and have had good luck for three years, I do have a set of crossovers for tweers, I could use them. Thanks

I guess I was assuming you were gonna use a higher power amp.It depends on power levels and cut off points, if its low powered and the cut off is in the 300+ range they(just caps) will work good.I just have a better safe than sorry outlook on things.