Though the following is oversimplified, it's what I use when thinking about this issue.
I use a speaker with an 89dB/w sensitivity (and ignore how it was measured). I assume that peaks on the order of 15dB must be accommodated (a figure I remember for the human voice, one of the most demanding instruments). One watt will provide a listening level of 89dB and the peaks will require 32w (with a doubling of power as 3dB). Therefore these speakers require the following:
dB---w------peak w
80---.125---4
89---1------32
98---8------256
Using this as a ballpark, my 8w SET into 89dB/w speakers should be capable of about 83dB (.25w with 8w peaks) at one meter. My listening position is twice that, so somewhere around 80dB would be right (neglecting room effects - and my system is in a really small room). Since I listen exclusively to classical music and nearly always to small ensembles and solo instruments, this level suites my listening habits just fine. YMMV
I use a speaker with an 89dB/w sensitivity (and ignore how it was measured). I assume that peaks on the order of 15dB must be accommodated (a figure I remember for the human voice, one of the most demanding instruments). One watt will provide a listening level of 89dB and the peaks will require 32w (with a doubling of power as 3dB). Therefore these speakers require the following:
dB---w------peak w
80---.125---4
89---1------32
98---8------256
Using this as a ballpark, my 8w SET into 89dB/w speakers should be capable of about 83dB (.25w with 8w peaks) at one meter. My listening position is twice that, so somewhere around 80dB would be right (neglecting room effects - and my system is in a really small room). Since I listen exclusively to classical music and nearly always to small ensembles and solo instruments, this level suites my listening habits just fine. YMMV