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
Ah Specs. I learned a while ago especially with speakers to only look at the sensitivity spec. The most current reason is my Dyn C1's are rated 45-22khz. My brother in law has Vienna Acoustic (forget which model) that are rated 32-25k and we both agree my Dyn's go lower. It could be due to the fact the VA's distort more at the lower frequencies (just a guess). Besides if I were a manufacturer I would look for a frequency band where the distortion is the lowest to publish. For me the same holds true for amps regarding watts (but that is a long story).

Bottom line is let your ears decide what sounds best ;-)
Green Mountain Audio is the only manufacturer I can recall consistantly giving speaker distortion specs.
Thanks guys but as a noob that really boggles my mind. you mean with all of the resources we have online in this day in age and no one is doing distortion comparisons amongst speakers for given decibel levels??? WHY????? cynical marketing reasons?
oh and PS...I would go by my ear but it is so difficult to tell A/B type comparisons. also hearing one place vs hearing it at home...different sources...etc...
Spartanmorning, One reason is that few manufacturers who use more expensive underhanged speakers would have clear advantage. No incentive for everybody else who is using overhang drivers to publish distortion. The other reason is that speaker distortion is not only performance at particular frequency and sound level but also at complex signal (music). Non-linear membrane action and membrane bending at higher frequencies creates intermodulation distortions. Speaker also has different phase shifts at different frequencies and presents complex load to amplifier that is difficult to measure. Specifying distortion at particular sound level and particular frequency driven by some perfect lab gear would not make much sense. There are few people on this forum who know speakers much better (design them for living) and I hope they will comment on this interesting thread.