Low pass filter question...?

Question

I have a Pioneer head unit with low pass options of 50 63 80 100 and 125 hz at 18 db octave...I have an Alpine amp with low pass options of 50 55 75 100 140 170 and 200 hz at 24db octave... I currently have the unit at 125 and the amp at 75...how would you set them?

Answer 1

I have a similar situation in one of my cars. Only the 24db per octave is in the head and there is a 12db per octave in my amp.

I don't use the crossover in the head unit. I only use the crossover in the amp set at about 65Hz.

I don't like the steep drop off in frequency myself.  

Answer 2

If the lpf on the the amp truly cuts off at the frequency they say then It won't matter what the head unit's lpf is set at as long as it's above that of the amp I would say set the lpf on the head unit at 125 and set the lpf on the amp anywhere u want.