This jumper-cap kit lets you fine-tune your speaker’s bass and treble using four jumpers A, B, C and D. The effect of each jumper is described below. - Jumper A: remove A’s jumper cap to limit super-deep bass and reduce distortion. - Jumper B: remove B’s jumper cap to increase bass; with B’s cap on, bass is reduced. - Jumpers C and D: used to control the height range; when the cap of Jumper C and Jumper D is put on, the sound of the highs is the loudest. - Jumpers A and B: used to control the audio effect of the bass range. A sets the lower limit, while B sets the upper limit of the bass audio range. Note: On some speakers, distortion can occur when the bass is turned up too much. Benefits and practical notes - Precise control of bass range and high frequency presence for customized listening. - Simple hardware adjustments without software. - Helps reduce distortion when boosting bass and tailors sound to different tracks and room acoustics. - Clear, repeatable adjustments aligned with the four-jumper scheme. use scenarios - Home stereo setup with strong bass but risk of distortion: remove A’s cap to limit deep bass and cleaner output. - Bass-heavy music or movies: remove B’s cap to increase bass, or keep B’s cap on to prevent overloading the speaker. - Want brighter highs for sparkling detail: put caps on C and D to maximize the highs.