Larryi, I think in a typical setting, a single 86 dB/W efficient speaker playing at one meter in free field (no room)with only 20 Watts available, might be significantly less loud than 99 dB.
http://myhometheater.homestead.com/splcalculator.html
I would guess that very few actually listen in such a manner. In what I (admitedly arbitrarily) suspect might be a more typical setting, using two speakers that are 86 dB/W, placed within 2'-4' from a roomer boundary, and heard from a distance of 3 meters would require closer to 45 Watts to achieve 99 dB
Though often cited, I don't believe the reason one typically doesn't listen at average levels of 99 dB because (the speakers) "...would be compressing like mad from overheating.", but, though appropriate for musical peaks, 99 dB is just uncomfortably loud for sustained listening.
http://myhometheater.homestead.com/splcalculator.html
I would guess that very few actually listen in such a manner. In what I (admitedly arbitrarily) suspect might be a more typical setting, using two speakers that are 86 dB/W, placed within 2'-4' from a roomer boundary, and heard from a distance of 3 meters would require closer to 45 Watts to achieve 99 dB
Though often cited, I don't believe the reason one typically doesn't listen at average levels of 99 dB because (the speakers) "...would be compressing like mad from overheating.", but, though appropriate for musical peaks, 99 dB is just uncomfortably loud for sustained listening.