The trouble with bass is you get the product of two factors both working against you. First of all, to produce a sound that is identically loud to the human ea

The trouble with bass is you get the product of two factors both working against you. First of all, to produce a sound that is identically loud to the human ear, the sound wave pressure amplitude has to increase tremendously as you go down in frequency. At 40 Hz, which is not very deep bass, you're talking a 40 dB SPL increase necessary over 1000 Hz. Furthermore, as the frequency drops, the sound waves become longer, meaning that with constructive interference, the volume of space in which you have to produce significant sound pressure increases with the inverse of frequency. Taken together, this means that at 40 Hz, this type of speaker must output 16*25 = 400 times as much sound energy as at 1000 Hz. To reach deep bass territory of 20 Hz, you're looking at a 1600 times increase in the energy required.