Originally Posted by mstarman

**CLARIFICATION**

Just to clear up some misconception about the capacitor value and its effect on bass filtering. By increasing the capacitor value, you will decrease the CUTOFF frequency, yes. However, this means you are allowing LESS bass to pass through to the speaker. So if you want to have more mid-bass, you should DECREASE the capacitor value. 67uF sounds very reasonable, though 220uF should work fine for most people.

Also, a note on polarization. Non-polarized capacitors would be highly recommended, as other people have commented. For those of you that may have POLARIZED capacitors laying around, you can turn these into NON-polarized capacitors. This is done by putting two capacitors in series, with the 'negative' terminals tied together, leaving the two positive ends to be attached to the spliced speaker wire. Also, keep in mind that when putting capacitors of the same value in series, the capacitance will be cut in half: meaning two polarized 220uF capacitors in series will form a single non-polarized capacitor with a new value of 110uF. Hope this helps.

Michael