Re: FIR filters
Not only that, but it will reduce the weight of the cabinet by half, and solve any performance issues you may be having in the bedroom. Also the subs will be in time at all audience positions.
Seriously, though, FIR is not magic. It will not make a box overall louder. Simply implementing some FIR filtering will also not necessarily improve polar coverage or sound quality. It could, but not everyone will use this filtering the same way, and in fact most use a combination of FIR and IIR filtering as it isn't realistic or desirable to apply FIR to every problem.
What is possible using FIR is an increase in peak SPL output, very short term. This is because in a normal signal processing chain the "ideal" signal is provided to the loudspeaker and the transducer/box then replays a band-limited and time-smeared version of it, which has lower crest factor and a less clean impulse. In effect FIR can be used to do the opposite, i.e. providing a smeared signal with lower crest factor to the speaker which the speaker then mangles back into perfect alignment, outputting a more perfect impulse than was put in! The potential increase is on the order of <3dB though, and will be evident mostly as a quality improvement rather than an increase in perceived loudness.
