Freeware - Hz Box by Higher Hz VST Plugin

https://higherhz.com/hz-box/

Hz Box is a free algorithmic soundbox emulator plugin that adds character by changing the timbral quality of any sound. The plugin can help define a sound’s place in your mix by giving it the richness and depth it needs.
Hz Box can also bring flat sounds to life with a little brightness and just the right amount of sparkle. Since we’re taking the concept of what a real-world soundbox does to sound, Hz Box can make subtle character changes or create an entirely new tonal profile.