Do you have problems with both SoundEffectVPlay (wav sounds) and BackgroundMusic (mp3 music)?
Maybe also the Application Output contains some information what might cause the sound to fail, can you have a look?
For the iOS devices: Can you also check if the hardware “mute” switch is turned off, as this also mutes the sound and is easy to overlook when testing.
It’s very strange that the audio doesn’t work only for this project but is ok on all the others.
It is likely that you have an issue somewhere in this project.
Are you certain that everything is set up correctly like
– all audio files are correctly placed in the assets directory and
– the relative path and the file-names specified in QML are correctly set without typos (e.g. uppercase/lowercase errors)?
Entity creation and destruction can affect the performance a bit, especially when creating many entities at once. You can use entity pooling to improve the performance, as entities are then created by reusing previously created and currently unused entities. Otherwise entities are always destroyed and created from scratch. In addition, Debug builds also perform less good than Release builds for publishing, so this can also affect the frame rate.