Jumper A and B control the bass frequency range. Jumper A sets the lower limit, while Jumper B sets the upper limit. Excessive bass can cause speaker distortion. To reduce distortion, remove the jumper cap from Jumper A to limit very low bass frequencies. Removing the cap from Jumper B increases bass output; with the cap in place, bass is reduced.Jumper C and D control the treble frequency range. With both caps installed, treble output is maximum. With only Jumper C capped, treble is reduced. With only Jumper D capped, treble is further reduced. With both caps removed, treble output is disabled.Use the splitter board as follows: Connect according to the labeled terminals (Treble, Low, Input), connect to your speaker, ensure proper enclosure sealing, then play audio and adjust jumpers for optimal sound. Typically, Jumper A is used while Jumper B remains unused. For treble adjustment, test different combinations of Jumpers C and D to achieve desired tonal balance.Common configurations include: - A + D: Enhanced bass response - A + C: Balanced clarity in both treble and bass - A + C + D: Clear treble and bass, with slight emphasis on treble - A + B + C + D: Emphasis on midrange frequencies If bass is excessive, remove the cap from Jumper A.Once optimal sound is achieved, secure the board to your speaker unit.Power rating: Up to 400W Impedance: 4–16 ohms Frequency response: Adjustable Color: Red Material: PC + metal Package includes: 1 × Frequency Divider Note: Actual product color may vary slightly due to lighting and screen settings. Measurement tolerance: ±1–3 cm.