"System-Wide Audio Boost Boom 2 acts as a volume booster for Mac that takes audio levels up a couple of notches. This works system-wide, so that your entire macOS X machine produces excellent volume all the time!

Controlled Boost A toggle-friendly Controlled Boost feature gives an intelligent control over the system’s audio output. Now adjust the volume to achieve an optimum experience without worrying about the excessively high volume on your Mac."

- Global Delight