# Blackman

> Blackman window for FFT spectrum analysis.

## Definition

* **Type:** Field
* **Namespace:** [UnityEngine](/engine/6000.7/script-reference/unityengine.md)
* **Assembly:** UnityEngine.AudioModule

```csharp
Blackman = 4
```

### Remarks

Window function: `W[n] = 0.42 - 0.5 " cos(2π " n/N) + 0.08 " cos(4π " n/N)`, where `n` is the sample index and `N` is the window length.

Pass this value to the `window` parameter of [AudioListener.GetSpectrumData](/engine/6000.7/script-reference/unityengine/audiolistener/getspectrumdata.md) or [AudioSource.GetSpectrumData](/engine/6000.7/script-reference/unityengine/audiosource/getspectrumdata.md). The window is applied before the FFT to reduce spectral leakage between frequency bins.

Use the Blackman window when you need lower sidelobes than [FFTWindow.Hamming](/engine/6000.7/script-reference/unityengine/fftwindow/hamming.md) or [FFTWindow.Hanning](/engine/6000.7/script-reference/unityengine/fftwindow/hanning.md) and can accept a wider main lobe. For even stronger sidelobe suppression, use [FFTWindow.BlackmanHarris](/engine/6000.7/script-reference/unityengine/fftwindow/blackmanharris.md).

Additional Resources: [FFTWindow](/engine/6000.7/script-reference/unityengine/fftwindow.md), [FFTWindow.BlackmanHarris](/engine/6000.7/script-reference/unityengine/fftwindow/blackmanharris.md), [FFTWindow.Hamming](/engine/6000.7/script-reference/unityengine/fftwindow/hamming.md)