Dayton Audio OmniMic V2 Precision Measurement System - Manual (Page 28)

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Polar Displays
Index
Polar displays are an Advanced Feature, provided by a non-live postcalculation using multiple saved
frequency response data files "Add-ed" to the OmniMic Frequency Response screen. The files must
have angle values assigned to them, and there must be at least three "Added" files present with
different angles assigned in order for a calculation to be possible. In general, seven or more files
should be used for good results. When you click the "Polar Display" button, the OmniMic system will
pause (halt incoming live measurements) as the Polar Display calculations are very intensive and
would interrupt live processing.
The purpose of a Polar Display is to reveal how the frequency response of a loudspeaker varies with
horizontal or vertical angles from the baffle. Speaker designers generally design loudspeakers for a
specified (usually, flat) frequency response at a position on-axis of a speaker and at some assumed
distance from the baffle. But such a response is not what a user actually hears in a real room --
though some sound that projects at off angles isn't initially aimed at a listener, that doesn't mean that
its effects won't be heard. If you point a speaker away from you, you will still hear it very nearly as
loudly than as if it was pointed at you. You may hear it a few milliseconds later, but it will certainly not
be insignificant. Usually, most of the energy you hear from a speaker actually wasn't initially directed
at you, but is reflecting from around the room before reaching you.
Research shows that users generally prefer that the spectrum of reflected sounds should resemble a
flat (or smoothly decreasing) response relative to that from the directly arriving sounds. This has
resulted in interest in the polar radiation patterns of loudspeakers, and in designs intended to address