https://flathub.org/...

https://github.com/wwmm/easyeffects

I highly suggest this app, especially on old pc with limited speakers or bad microphones. Even when you have good speakers is still great for any limited audio streams (podcasts/videos/web radio), the "Crystalizer" option does wonders.

Easy Effects is an advanced audio manipulation tool. It includes an equalizer, limiter, compressor and a reverberation tool, just to mention a few. To complement this there is also a built in spectrum analyzer. Easy Effects is the successor to PulseEffects. Easy Effects only supports PipeWire's audio server. PulseAudio users should instead use PulseEffects. Because Easy Effects uses the default PipeWire sound server it will work with most, if not all, applications you use. All supported applications are presented in the main window, where each can be enabled individually. Easy Effects is able to apply effects to an input device, such as a microphone. This is, for example, useful in audio recording, but it also works well during voice conversations.