Of course, I cannot add much than "read again and carefully what these guys said, they are very well versed in all those stuff", but there is some additional thing that always annoyed me regarding all these db and wattage things:
Rating are already not so perfect for 1W. Still all we have is a rating with a 1W program, while we are often feading them with way more than 1W.
And guess what: I see absolutely no reason why a 25W rated speaker would have the exact same efficiency at 1W and at, say, 20W. It's a well known fact that guitar speakers tend to distort when approaching their limits. It's even considered as an interesting effect by some and guitar speakers tend to be made so that this start of distortion is not destructive for the device. On an electro-mechanical device distortion always equates to lower efficiency. It might be a good thing, though: I suspect this lower efficiency at the limits might be partially linked with cone velocity and as such be more pronounced on those pesky high frequencies - especially with a heavier speaker cone.
So I would say the SPL rating should read nnn db AT 1W and not nnn db/W, and the curve itself should be taken with a big pinch of salt if you intend to use the speaker attached to a power amp that can output close to your speakers rating.
The values might be representative enough if you stay well bellow the maximum wattage the speaker can accept though, but I suspect at least the efficiency in highest frequencies is affected way before what most people have in mind.
I might be wrong though, so wait 'till those knowledgeable guys correct me before making your own conclusions.
Rating are already not so perfect for 1W. Still all we have is a rating with a 1W program, while we are often feading them with way more than 1W.
And guess what: I see absolutely no reason why a 25W rated speaker would have the exact same efficiency at 1W and at, say, 20W. It's a well known fact that guitar speakers tend to distort when approaching their limits. It's even considered as an interesting effect by some and guitar speakers tend to be made so that this start of distortion is not destructive for the device. On an electro-mechanical device distortion always equates to lower efficiency. It might be a good thing, though: I suspect this lower efficiency at the limits might be partially linked with cone velocity and as such be more pronounced on those pesky high frequencies - especially with a heavier speaker cone.
So I would say the SPL rating should read nnn db AT 1W and not nnn db/W, and the curve itself should be taken with a big pinch of salt if you intend to use the speaker attached to a power amp that can output close to your speakers rating.
The values might be representative enough if you stay well bellow the maximum wattage the speaker can accept though, but I suspect at least the efficiency in highest frequencies is affected way before what most people have in mind.
I might be wrong though, so wait 'till those knowledgeable guys correct me before making your own conclusions.