depends , upon tunning frequency
and subsonic filter is must w.r.t tunning frequency
its doesnt envolves power
power give a boost on every frequency
and usage of filters
Low Pass filter and subsonic filters
cuts of frequnecy in -1db,-2db,-3db............ in a slope form
( the cutoff slope depends upon filters)
like (6db octave ,12db octave , 18db octave , 24db octave)
the best filterteration is higher db , 24db.....
actuall cutoff db like -1,-2db etc
reduces powering of sub on that frequency
( it will take so long to explain...)