For a quick and reasonably easy solution, look at Ozone 4 at www.izotope.com

and while you are there, read their free guide on mastering at http://www.izotope.com/products/audio/ozone/guides.html The first three pages of the text will clear it all up for you.

With Ozone, you can make subtle improvements, or (horrors) slam your audio right to the max.

Ozone is not free; it costs $250 for new users, and it is available as a DirectX or VST plugin. Many of us who use SONAR highly recommend it as a one-program mastering solution. It bridges the gap between nothing and hugely expensive mastering tools. Plus, it requires no PACE or dongle (undesirable forms of copy protection). It may be the quickest and easiest way to improve home studio recordings.

BIAB 2024 Win Audiophile. Software: Studio One 6.5 Pro, Swam horns, Acoustica-7, Notion 6; Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus Studio 192, Presonus Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors