I find that 40 Hz, which is the lowest crossover point on my 16-46 PC+ is too high. 40 Hz is that of a frequency which really is ear-deafning and annoying. Since my mains (Canton Ergo RC-L) extend very well down to 30 Hz (even lower but at very low volume), I want only that real bottom to be filled, and nothing else. Is there a low level way to set crossover to 30 Hz? Build an external filter or something? Any input greatly appreciated.