With any panel speaker the measurement is done the same way as it is with a point source speaker.
What happens is most of the sound made by the speaker is not picked up by the microphone. Examples of this are the Magnaplanars, Martin-Logans, and also mbls (which are omnis instead of planars).
Its possible to correct for this and create a number that is the equivalent of 1 watt/ 1 meter or 2.83V/i meter. But usually the single-mic number is stated.
This causes the speaker to look about 6 db less efficient or sensitive on paper than it really is. It sounds like Martin-Logan has corrected for the fact of their speakers being panels per the example given in the opening post. The adjusted number of 92 db is actually about right, although if you do the traditional measurement you get something more like 87db (which suggests that ML was being conservative).
What happens is most of the sound made by the speaker is not picked up by the microphone. Examples of this are the Magnaplanars, Martin-Logans, and also mbls (which are omnis instead of planars).
Its possible to correct for this and create a number that is the equivalent of 1 watt/ 1 meter or 2.83V/i meter. But usually the single-mic number is stated.
This causes the speaker to look about 6 db less efficient or sensitive on paper than it really is. It sounds like Martin-Logan has corrected for the fact of their speakers being panels per the example given in the opening post. The adjusted number of 92 db is actually about right, although if you do the traditional measurement you get something more like 87db (which suggests that ML was being conservative).