analyzer

DFasma is a free open-source software which is used to compare audio files in time and frequency. The comparison is first visual, using wavforms and spectra. It is also possible to listen to time-frequency segments in order to allow perceptual comparison.

4 Band Parametric EQ (fil4.lv2) is a graphical EQ with High/Low shelfs and High/Low Pass filters which is based on DSP from Fons Adriaensen's highly regarded fil-plugin. It is available in both mono and stereo variants and has a spectrum display plus waterfall FFT history built-in. The display also has vertical zoom and the window can be resized.

x42-plugins is a collection of cross platform LV2 audio/MIDI plugins, currently featuring over 80 plugins from 11 repositories.

The x42-plugins collection consists of the following -

SoX, which stands for Sound eXchange, is a command line tool used for various types of audio processing and manipulation. Sox is a very flexible tool and can be used in scripting. Amongst other things, it can be used for audio format conversion/encoding, editing, applying of effects, and the playback/recording of audio files.

FreqTweak is a tool for FFT-based realtime audio spectral manipulation and display. It provides several algorithms for processing audio data in the frequency domain and a highly interactive GUI to manipulate the associated filters for each. It also provides high-resolution spectral displays in the form of scrolling-raster spectrograms and energy vs frequency plots displaying both pre- and post-processed spectra.

Sonic Visualiser is an application for inspecting and analysing the contents of music audio files. It combines powerful waveform and spectral visualisation tools with automated feature extraction plugins and annotation capabilities.

The aim of Sonic Visualiser is to be the first program you reach for when want to study a musical recording rather than simply listen to it.

JAMin is a mastering suite for Linux. It is a standalone program but can, via JACK, can be inserted into any programs signal path.

Some of JAMin's features include:
30 band graphic EQ
1023 band hand drawn EQ with parametric controls
Spectrum analyser
Multiband compression
Lookahead brickwall limiter