It's sad to hear how many systems are spoiled by poor bass – slow, boomy, one-note, overhanging bass. Adding sub-woofers can be an answer.
See also our advice about speaker positioning under Tips –crucial.
Raising the question of sub-woofers with customers can be a real turn-off!
It's the bad experiences that make a lot of people say they don’t need or even like deep bass, so why have a subwoofer? “Why do I want a sub when the music I play has little bass in it?” Or even worse: “All the subwoofers I’ve heard add more boom than bass! So what’s the point?!”
Controlling the room is the point. But like absolutely everything else in audio, it depends how you do it.
Recordings contain frequencies – harmonics of the fundamental note – that extend above and below our normal hearing range. If you don’t reproduce the deep harmonics cleanly, music in the audible range loses presence, ambience and pace. For similar reasons adding a super-tweeter will properly define the leading edges of notes across the whole audio range, even the bass, for a tighter, crisper sound and better timing.
If we demonstrate with subwoofers, even with big speakers, then turn them off the instant reaction is, “It’s gone flat! It’s lost interest and ambience.”
Low frequencies below 30Hz easily excite rooms to boom, creating unreal bass that kills the rhythm and slows the pace, so it's crucial to avoid over-driving the room into resonance.
First you re-position your main speakers to optimise the imaging, space and openness. Now you use the sub to cancel any remaining excess bass! That requires “smart” subs from Audio Physic or Velodyne that can be matched to the room. They have controls that roll off the deepest bass above your room’s mode to give a seamless clean sound, top to bottom. No more boom.
Free, extended bass is revealed plus greater richness and ambience in the mid-range. Perhaps for the first time you will hear individual notes in a bass guitar run or a plucked double bass. That is musically immensely satisfying.
If you've read into this topic before you will probaly have noticed that two subs are recommended where possible. We heartily endorse that advice, not because we sell another sub, but because two drive the room more evenly and the sound seems better focussed and stable, especially if you move off-axis.