This plugin can be used to keep your music loudness on a constant level.

Allows full control of all aspects of the processing. There are over 300 adjustable controls! Suitable for PC-based music playback, Server-based music playout systems for home or commercial use, Netcasting and Low-power AM/FM transmissions. This plug-in caters to audio engineers and enthusiasts who wish to have full control, but will likely overwhelm users who do not need to have this level of control.

Stereo Tool is a professional low latency audio processor that is used by hundreds of FM, AM and web radio stations all over the world, by musicians who use it to process their recordings, and by hundreds of thousands of people who use the free version¹ to listen to music on their PC.