To make changes to the sound quality on your TIDAL mobile app, go to My Collection, and then click on to access Settings. In Settings, scroll down to select Streaming to manage your sound quality. Depending on your subscription type you will be able to select from two to four of the following options. 

Normal - Reduced data usage for slower connections.

High - Best compromise between data usage and sound quality.

HiFi - Lossless CD quality.

Master - Authenticated files from the mastering process. Studio quality. Unrivaled clarity and depth.