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Gradient Helsinki 1.5

Click on links for full set of plots.

Horizontal directivity plots

Gradient Helsinki 1.5 H Contour Plot

Full horizontal contour plot

Vertical directivity plots

Gradient Helsinki 1.5 V Contour Plot

Full vertical contour plot

Directivity index plots

Gradient Helsinki 1.5 Full Sphere DI Plot

Full-sphere directivity index plot

Constant directivity metrics plots

Gradient Helsinki 1.5 Horizontal Polar XCorr Plot

Full horizontal NACC plot

Measurement notes:

  1. Date performed: 12 July 2014 (H); 14 July 2014 (V)
  2. Nominal measurement distance: 1.6 meters
  3. Transducer type: three-way dynamic; unbaffled woofer
  4. Exponential sine sweep settings:
    • Frequency range: 20 Hz to 48 kHz
    • Duration: 5 seconds
  5. Impulse response window settings:
    • Type: Tukey (cosine fade-in, flat, cosine fade-out)
    • Duration: (0.5, 3, 0.5) msec
  6. Frequency resolution: 250 Hz
  7. Spectral smoothing: 1/24th octave
  8. Directivity index averaging range: 500 Hz to 20 kHz
  9. Alignment: The microphone was aligned with the center of the mid-range transducer. The axis of rotation also passed through this transducer.