Although possible to adjust bass in speakers using a conventional tone control, very often the tone control affects all speakers globally. It may be desirable to reduce bass in a pair of ceiling speakers in the kitchen, but not the outdoor speakers in a distributed audio set-up. Alternatively, it may be useful to reduce the bass response of a speaker (or speaker pairs) in systems where no tone controls exist. Using in-line capacitors (or "bass blockers") can resolve these problems without much challenge. These are passive high pass filters, designed to block unwanted low frequencies.
Locate the impedance rating on the rear of the speaker. Most home speakers are 8 ohms; most automotive drivers are 4 ohms. The value of bass blocker will be determined by this impedance. High passing at 80Hz in a car speaker at 4 ohms will equate to 160Hz for an 8 ohm driver.
Remove the positive speaker wire on the rear of the speaker. It may be necessary to push down a spring terminal, or unscrew a binding post to free the wire. It is not necessary to remove the negative lead.
Strip 1/2 inch of insulation from one end of the bass blocker. Twist the bare wire, eliminating frayed strands.
Crimp an insulated connector of appropriate gauge on the end of the speaker wire previously disconnected from the speaker. On the other end of the connector, strip and crimp in the other end of the bass blocker.
Insert the bare wire on the bass blocker back into the positive terminal on the speaker.