Stupid speaker test question...please help a n00b


Why aren't speakers tested by measuring the output sound waves vs the input wave signals? Would this not be the easiest way of testing distortion introduced by the speaker? Assuming you control all the other parameters of the test of course...

Thanks for the help!
spartanmorning
We are well beyond my knowledge level (obviously) but I have to say I find this field of 'hi-fi' quite frustrating. There seems to be so much misinformation and disinformation that obtaining any semblance of understanding would require a formal acoustics degree of some variety.
"I have to say I find this field of 'hi-fi' quite frustrating"

You're not alone. We are here to learn.
IMHO, John Dunlavy built some of the finest loudspeakers, and he depended on tests more than most. He seemed to think that step and pulse response were particularly important.
Square wave reproduction (as noted by Unsound) is a darned good objective test. Decades ago Ohm cited this in their promotional material. I have been told that a few other speakers pass this test.
One limiting issue in hifi is measurement vs perception.
Apparently, everything that can be measured doesn't matter and some things which matter are not measured...or perhaps measurable (yet). Add in literally hundreds of tweaks ranging from Schumann frequency generators to having a Seance before listening doesn't help much, either.

Toss in a good mix of those in favor of DBT, SBT and whathaveyou and you've got a real mess.

Contentions that 'amplifiers run in there linear, non-clipping area all sound alike' without reference to what speaker is being driven, don't necessarily help.

'Ya can't take it TOO seriously because 'that way lies madness'.

Some of what would seem to be basic advice like....listen before buying or find a good sales guy to trust and work with.....may not help because a person new to this 'hobby' doesn't necessarily know who to listen TO or what to listen FOR.

Advanced HIFI does a poor job of selling itself, but that's another thread.