What follows are some assorted measurements, gathered during the development and testing of the Gen2 waveguides.
Important notes:
Note 1: The indicated absolute pressure levels are NOT the actual levels
and not even comparable between different graphs -
the SPL scale is not calibrated, nor were the driving voltage
levels held always the same during different measurement sessions.
This means that the graphs below display only the shapes of
the raw frequency responses of each individual driver tested in
combination with a particular waveguide and throat adapter. No further processing (e.g. EQ) has been applied.
Note 2: These are only quick informative measurements,
typically sampled for off-axis angles roughly between 0° and 30°, with 10° step, but
the exact values may differ slightly between different sessions.
It is not necessary to measure the whole radiation pattern each time, as the match between a
BEM simulation and the actual measurement is very good in general
(see e.g.
this diyAudio post) and the directivity is substantially independent of a driver used.
The measurements have been all done indoors in a limited space, gated with 4.5 - 5 ms time window.
