> For the complete documentation index, see [llms.txt](https://docs.lmms.io/user-manual/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lmms.io/user-manual/effects/spectrum-analyzer.md).

# Spectrum Analyzer

## Spectrum Analyzer in 1.2 and earlier

![Spectrum Analyzer](/files/-LuiUFUpKHXGX13XQHos)

This plugin visualizes the frequencies present in the signal it monitors.

### Graph

* **X axis:** shows frequencies from 20 Hz to 20,000 Hz, divided into [octaves](https://en.wikipedia.org/wiki/Octave_\(electronics\)) (this makes the X axis appear nonlinear).
* **Y axis:** shows amplitude from 40 dB to -60 dB (displayed linearly with respect to decibels).

### Buttons

* **Linear Spectrum:** toggles linear display of frequencies (rather than by octaves).
* **Linear Y axis:** toggles linear display of amplitude (rather than by decibels).

## Spectrum Analyzer in 1.3 and later

![Spectrum Analyzer](/files/-MUEGpAKQ1AlpFuKEBSt)

### Buttons

* **Waterfall:**
* **Averaging:** enables averaging of display frames.
* **Stereo:** enables the display of LR channels independently, with the Left channel represented by Blue and the Right channel by Red.
* **Peak hold:** enables a "ghost" line that shows the peaks of the spectrum.
* **Pause/Play button:** enables/disables the plugin.
* **Snowflake:** freezes plugin display (along with the data displayed).

### Drop-down Menus

* **Frequency Range** <img src="/files/-MUELePGTfFXno9oRhIX" alt="" data-size="original">**:** alters the range of displayed frequencies.
* **Amplitude Range** <img src="/files/-MUEM4dB6eeItBz2VKdO" alt="" data-size="original">**:** alters the range of displayed amplitude.
* **FFT Block Size** <img src="/files/-MUEMH-ff7rLpzMHbmqp" alt="" data-size="original"> **:** alters the frequency resolution of the display (Higher resolutions come at the cost of FPS).
* **FFT Window Type** <img src="/files/-MUEMOIQAz5RHKuq4fBD" alt="" data-size="original"> **:** changes algorithm used to remove FFT-related noise.&#x20;
  * Blackmann-Harris displays the least noise but has low frequency resolution.
  * Rectangular displays the most noise but has high frequency resolution.

### Graph

* **X axis:** shows frequencies based on the Frequency range drop-down menu.
* **Y axis:** shows amplitude based on the Amplitude range drop-down menu.

{% hint style="info" %}
Clicking in the spectrum/waterfall display adds a ruler/cursor with value readouts.
{% endhint %}

### Advanced

* **Envelope Res:** alters the resolution of the Peak envelope ("Peak Hold").
* **Spectrum Res:** alters the resolution of the display curve with fill-in color.&#x20;
* **Falloff Factor:** alters the speed at which the peak envelope ("Peak Hold") falls to zero.
* **Averaging Weight:** alters how the display curve reacts to new samples.
  * High value: fast reaction, low jitter reduction. enables real-time spectrogram.
  * Low value: slow reaction, high jitter reduction.
* **Waterfall Height:** alters the time range, or the amount of temporarily stored frames, of displayed frequencies in the Waterfall display.
* **Waterfall Gamma:** alters the amount of gamma correction in the Waterfall display.
* **Window Overlap:** alters how many times each FFT sample is processed (higher values can help improve FPS).
* **Zero Padding:** improves resolution when using a smaller FFT Block size, at the cost of performance.
