adjustable bandpass crossover

 I need to crossover midbass drivers, does anyone know where i can find an adjustable bandpass crossover? Or an amp with that function built in? I know the Sundown Audio SAX 100.4D does, but its much too large to fit under my seat, and a 'Fosgate 3sixty.2" is way too expensive to consider -  lol

Thanks

In many cases it works fine to simply low-pass your mid bass and let the low end roll off naturally.  What kind of band are you trying to hit?