Pulseaudio Parametric Equalizer is a python GUI to insert a fully parametric three band equalizer with high and low shelves into the pulseaudio audio server.

Pulseaudio Parametric Equalizer is a python GUI to insert a fully parametric three band equalizer with high and low shelves into the pulseaudio audio server.

The same beautiful Material Design experience you love on the browser, just as a dedicated desktop player.

XiX Player is a free, easy to use, multi-platform music player that currently runs in Linux, Linux ARM (Raspberry Pi), Windows & MacOS Intel
Features:
- Supports the following file formats: MP3, OGG, M4A (non-DRM), AAC, FLAC, OPUS, APE, DFF, WAV
- Play & rip your CDs to MP3 or FLAC with CD-Text and CDDB support.
- Rip CD/DVD tracks to MP3 or FLAC. Needs mplayer.
- See albums the chosen artist is on and vice versa.
- Create and use playlists.
- Online radio stations + presets.
- Record online radio stations.
- Schedule Radio station recordings.
- Listen to & download podcasts.
- Play license free audio from the Internet Archive.
- Show the lyrics and CD covers of the song being played.
- Shuffle and repeat.
- Reverse play.
- Crossfading & trimming.
- Search.
- Rate your songs.
- EQ + FXs (Flanger, Echo & Reverb).
- Set EQ & trim for individual songs.
- Copy, delete or rename files.
- Change ID3 tag (only for MP3/OGG/FLAC/APE).
- Multiple tagging / renaming.
- Theme support (Basic).

SonicBirth is an AudioUnit designing MacOS application. The first in its category, it allows users to build their own AudioUnit plugins, either by working with existing circuits or by creating circuits completely from scratch. SonicBirth is also a free AudioUnits package, as it comes bundled with a set of plugins designed for standalone use as plugins as well as pre-constructed circuits to modify or build upon for creating new plugins. Whether you’re looking for traditional eqs, compressors, and reverbs, or softsynths, distortion, and filters, etc., SonicBirth allows you unprecedented freedom and creativity over your sound.

JAMin is the JACK Audio Connection Kit (JACK) Audio Mastering interface. JAMin is an open source application designed to perform professional audio mastering of stereo input streams. It uses LADSPA for digital signal processing (DSP). JAMin is licensed under the GPL.
Features:
- Linear filters
- JACK I/O
- 30 band graphic EQ
- 1023 band hand drawn EQ with parametric controls
- Spectrum analyser
- 3 band peak compressor
- Lookahead brickwall limiter
- Multiband stereo processing
- Presets and scenes
- Loudness maximizer

The freeDSP is an open-source digital signal processor family for the do-it-yourself community. The applications range from active loudspeaker concepts (digital crossovers, bass enhancement, …) and room equalization over advanced musical effect processors to car audio signal processing.

Blazing Fast Audio Player for Win32 Environments
Features:
- GNU General Public License
- Freeform Skins
- Simple User Interface
- Advanced Playlist Editor
- Internet Streaming
- ID3 Multi Tagger
- File Renamer
- Fast mp3->wav Converter
- MAD mpeg Engine
- OGG Vorbis Support
- Winamp Input Plugins Support
- Smallest executable programmed in blazing fast ‘C’
- Continuous Play
- 8 Band Convolution Equalizer
- Lot’s more…

rePhase is a FIR generation tool for building fully linear-phase active crossovers with arbitrary slopes.
It also let you manually compensate for the phase shifts of your loudspeakers and existing crossovers, be it active or passive.
Once generated, the FIR can be applied using any hardware (openDRC, miniSHARC, Najda, …) or software (foobar, convolver, JRiver, …), stereo or multi-way convolution engine.
sourceforge.net/projects/rephase
Equalizer APO, REW and Rephase WOW! ~ diyAudio
en.wikipedia.org/wiki/Digital_room_correction
Equalizer APO is a parametric / graphic equalizer for Windows. It is implemented as an Audio Processing Object (APO) for the system effect infrastructure introduced with Windows Vista.
Features:
- virtually unlimited number of filters
- works on any number of channels
- very low latency, which makes it suited for interactive applications
- low CPU usage
- modular graphical user interface
- VST plugin support
- integrates into Voicemeeter (www.voicemeeter.com)
Equalizer APO is best used in conjunction with Room EQ Wizard (www.roomeqwizard.com ), because it can read its filter text file format.

sourceforge.net/projects/equalizerapo
Discussion
Documentation
Downloads
Peace Equalizer
EQ APO GUI
mega-switcher
REW is free room acoustics analysis software for measuring and analyzing room and loudspeaker responses. The audio analysis features of REW help you optimize the acoustics of your listening room, studio or home theater and find the best locations for your speakers, subwoofers and listening position.

www.roomeqwizard.com
www.hometheatershack.com/forums/rew-forum
sourceforge.net/projects/equalizerapo
Multi-Sub Optimizer
Convolver – A Convolution Plugin