Reading through the posts so far, the answers from @georgehifi read the most correctly to me.
Watts, or power, is equal to voltage multiplied by current. But an individual speaker may want more voltage at some frequencies, versus more current at other frequencies. And if your amplifier is limited in one of those dimensions, it will have trouble driving the speaker.
There are other amplifier considerations for sound quality, but specifically to the question of high power ratings not having drive capability, it's the current and voltage numbers you are looking for.
The SPL calculator referenced earlier assumes a simple speaker load and unlimited current/voltage capability. I use it too, but only as a guide.
Watts, or power, is equal to voltage multiplied by current. But an individual speaker may want more voltage at some frequencies, versus more current at other frequencies. And if your amplifier is limited in one of those dimensions, it will have trouble driving the speaker.
There are other amplifier considerations for sound quality, but specifically to the question of high power ratings not having drive capability, it's the current and voltage numbers you are looking for.
The SPL calculator referenced earlier assumes a simple speaker load and unlimited current/voltage capability. I use it too, but only as a guide.