speaker measurement geometry


2013-04-25 5:52 am
Perhaps this should be obvious to me, but it isn't.

When measuring a speaker on and off axis, say at 1 meter, does one:

A) measure at different angles from the speaker axis along an arc with a radius of 1 meter? In this case, distance of 0degrees, 15degrees, 30degrees measurements are all equal to 1m.


B) measure at the intersect of rays oriented at different angles and a line perpendicular to the axis centered at 1 meter on axis? In this case, distance of 0degrees equals 1m, but all other angles have longer measurement distances.