Window Function Bandwidth Rechner — Formel

Window Function Bandwidth

Window functions reduce spectral leakage but widen the effective frequency resolution.

Equivalent Noise Bandwidth (ENBW)

ENBW = Bin Width x ENBW Factor

ENBW factors for common windows:

  • Rectangular: 1.00 (narrowest but worst leakage)
  • Hamming: 1.36
  • Hann: 1.50
  • Blackman: 1.73
  • Flat Top: 3.77 (best amplitude accuracy)

    • The choice of window balances frequency resolution against spectral leakage. No window is universally best.

    Lösungsbeispiel

    1024-point FFT at 48 kHz comparing window functions.

    1. Bin width: 48,000 / 1,024 = 46.875 Hz
    2. Rectangular ENBW: 46.875 x 1.0 = 46.88 Hz
    3. Hann ENBW: 46.875 x 1.5 = 70.31 Hz
    4. Blackman ENBW: 46.875 x 1.73 = 81.09 Hz