Whenever you change the audio quality (whether from 128K to 320K or vice versa) your existing Offline Songs will be temporarily cleared in order to download tracks in the right quality.Depending on the number of Offline Songs you have, and your internet connection, the amount of time needed for KKBOX to download all tracks in your playlist may vary. We do not recommend changing the audio quality unless you have the need to.1. Tap [My Library] → the gear icon to the top right corner of the page → [Playback].2. Tap [Audio Quality] and select your preferred settings.　※If you do not find options higher than 320K, it is possible you have not upgraded to Lossless Quality plan (available only in Singapore, Hong Kong and Taiwan).