Thanks for your question, but I don’t really have any suggestions because I’ve never used it for bass guitar. Theoretically, it should work because the circuit accepts very low frequencies. The suggested trim pot settings would be a good place to start…but I expect anyone who builds a Quaverato to mess around with these until they like the sound…same is true for anyone building it for bass guitar. You’ll have to experiment with the dip switch settings. You may like how it sounds with the suggested settings, or you may want to set the crossover point to a lower frequency, and then play with the ratios of highs to lows with the trim pots. Sorry I can’t give you more specifics.