Quote Originally Posted by anthonyTD View Post
Most reputable speaker drive unit manufacturer used to state Max SPL figures as well as Max power handling, one could easily establish then for eg, if a drive unit had a maximum SPL of say 114 db, and a sensitivity of 96 db per watt, per mtr, then well,,,I am sure most will understand where I am coming from on this...
Distortion, and paticularly certain aspects of distortion can be a tel tale sign that something is too loud, however, when you have an amp that has lots of clean power, then it can be quite easy to reach SPL levels not only damaging to the drive unit, but to long term human hearing too!
It's far more commonly quoted for single drive units than for speaker systems of course and for obvious reasons! If where you are going here is to agree with phar-off then yes if you have an anechoic chamber, a calibrated measuring mic, a source of a test signal (usually pink noise) and can set the mic up precisely on axis at one Meter then it is possible to do it. Now try it in a normal reflective room, using music as the signal, with a pair of multiway speakers rather than a single drive unit and a typically only +/- 20% accurate SPL meter.... Absolutely no way in a month of Sundays will you get any sort of meaningful measurement whatsoever....