Subs fill in the 'bottom' that the majority of speakers can't 'reach', w/out distorting their 'upper' frequencies. Case in point:
I happened to be @ a instrument b&m store where some musicians started goofing about with various 'toys'. While the 'regular frequencies' (80hz+) were covered by the monitors Just Fine, the 'subs' (which had 'ribbons' @ their ports, wagging about...) were 'filling in' the bassline that the monitors 'faded' from. So, I took that as an 'instructive moment' that Any speaker shouldn't be expected to cover Everything....esp. when it came to moving 'bass line air'....since bass is mostly 'air movement' @ a major (and physical) process. The aforementioned 'ribbons' were wagging about, in and out of their ports. It's just how much 'air' you can excite, pure physics....
You want 'concert sound'? Subs.
I happened to be @ a instrument b&m store where some musicians started goofing about with various 'toys'. While the 'regular frequencies' (80hz+) were covered by the monitors Just Fine, the 'subs' (which had 'ribbons' @ their ports, wagging about...) were 'filling in' the bassline that the monitors 'faded' from. So, I took that as an 'instructive moment' that Any speaker shouldn't be expected to cover Everything....esp. when it came to moving 'bass line air'....since bass is mostly 'air movement' @ a major (and physical) process. The aforementioned 'ribbons' were wagging about, in and out of their ports. It's just how much 'air' you can excite, pure physics....
You want 'concert sound'? Subs.