Originally Posted by arnyk
Both the CM2 and CM9 speakers have 89 dB/W sensitivity which means that they should be equally loud with equal power.
If only it was that easy.
Yes the "ratings" maybe the same-but where did the ratings come from?
Is it with the same input signal ( either 1 watt or 2.83V?) That could make a difference-DON'T ASSUME it was the same input.
Next what does the number actually mean? Is it an average across the freq range or some peak in the response? That could also make a big difference in how loud the different speakers "appear" to be.
A simple number will result in a easy to understand WRONG answer. You HAVE to look at a MEASURED response curve to get a real idea of what the ACTUAL SPL is.
That-and knowing what the drive signal is.
I prefer the 2.83V input because you CANNOT drive a loudspeaker with 1 Watt. If you look at the impedance cure you will see that the ACTUAL power will be all over the map with the same input VOLTAGE.
The 1 W rating comes from a 2.83V input into an "assumed" 8 ohm loudspeaker. If the speaker is not exactly 8 ohms (they are not-despite what the spec sheet says), the the actual power will be different.
Just sayin' that it is not always that simple.
So between possibly a different input voltage and where the response was measured, you could have very different actual SPL.