If you are new to high resolution audio, you might experience music that is softer in volume than the mainstream music catalog. There is nothing wrong with the music. It is a choice made by the engineers and producers to allow full dynamic range, which mean the body of the music may sound softer in order to not "flatten" or "compress" the peak signals in the music.
Many of these peaks in music happen when acoustic instruments are plucked or struck like a cymbal, piano, guitar or other percussive instrument. The first 'attack' of an instrument can be quiet dramatic in peak volume yet drop off quickly to a lower volume, which is natural. If the volume levels are raised, these peaks will cause distortion.
Mainstream music has adopted the practic of 'compressing' the peaks and increasing the body of the music's volume. It is often referred to as the 'volume wars'. Over the last 20 years, music production has leaned towards louder music as being 'better'. Most audiophile engineers and listeners feel this increase in volume negatively affects the actual tone and sound. These engineers have chosen to not compress the mixes and instead ask the listener to use their volume controls to increase the sound to receive an enhanced listening experience of tone.