I was able to finally get a proper GUI equalizer working for the system wide sound. Compiling from this github which was made for linux:
pulseaudio-equalizer-ladspa.
The only issue I face now is that I can not get some applications to output it's sound to the "FFT Based equalizer" virtual sound device which the "pulseaudio-equalizer-ladspa" created.
Such as "chromium", have no idea how I can output it's sound to the "FFT Based equalizer" virtual sound device, chromium simply rejects to output the sound to it even when I selected "FFT Based equalizer" virtual sound device as my main sound output source on the KDE's volume settings.
Whats weird is that "chrome"(not chromium) which uses the "compact-linux" output it's sound to the "FFT Based equalizer" virtual sound device, however chrome keeps crashing every 5 mins.
It's seems FreeBSD is simultaneously outputting two sound source devices at the same time, have no idea why. One for the "FFT Based equalizer" and another seems to be a default sound device which is chromium outputting it's sound to.
Edit:
Alright, I'm learning so much about software and hardware when fully entering relying on FreeBSD OS, everything needs to be configured manually and need to know a lot about low level workings of how software/hardware, which is great.
I was able to make chromium output it's sound to the pulseaudio GUI multi-band equalizer. The issue was that I installed chromium via
pkg install
and had to delete it.
I then had to compile and install chromium from the ports tree in which I had to disable "snido" (FreeBSD's defaults sound server) and enable ALSA and pulseaudio in
make config
. Then started compiling, it took slightly less than 4 hours to build and viola, chromium is now outputting sound to the pulseaudio GUI multi-band equalizer, I can finally get back listing to tutorials and lectures and precisely fine tune the audio so that it's not annoying to my ears with high pitched and high bass audios which are not mastered properly.
Although this is not ideal in my opinion, since I prefer to use Unix OSS, but no one has made a professional GUI multi-band equalizer for it as compared to pulseaudio.