Polar Graphs & Axis

Front vs. Side Address

Examples

1. Cardioid (Bartlett)
2. Comparisons (Holman, Gibson, Sphere Drums)
3. Use of Null Spots (Stage Monitor)

Polar Pattern Frequency Response

• Published polar graphs are at 1 kHz.
• Low frequencies have longer wavelengths, which defeat the directionality in the design.
• High frequencies have shorter wavelengths, and the mic itself physically gets in their way.
• It's typical for a cardioid (at 1 kHz) to actually be more like an omni at 100 Hz, and a hypercardioid at 8 kHz.

Proximity Effect

An increase in the bass response within about 3' of a uni- or bidirectional (non-omni) mic.

Many mics have built-in low-cut roll-off filters to compensate.

Examples:  Mic Techniques, Holman, Mics & Mixers video

Compared to other patterns, omnidirectionals...

Have an extended low frequency response (20-60 Hz):

Cardioid

Compared to other patterns, omnidirectionals...

Have a flatter frequency response for sounds off-axis:

Shotgun

omni vs. blumlein stereo example

Changing Polar Patterns

• Interchangable capsules (be careful!)
• Switches on dual diaphragm mics (control room level down!)
• Pad switches