If you're not getting the sound you expect from your system, try these suggestions:
Try moving your device closer to the speaker. Bluetooth range is about 9 metres. Range is reduced when interference is present. Interference includes things like walls, multiple Bluetooth devices in the same area, pockets/handbags/purses, wireless routers, microwaves, cordless phones etc.
Reduce the number of applications running on your Bluetooth device. Running multiple apps can reduce reliability if the device is trying to do too much at once. Close nonessential apps and check whether the sound improves
Try turning off Wi-Fi® on the device
Reboot the Bluetooth device. This is typically done by shutting it down completely and then restarting it
Try a different Bluetooth device to determine whether there is an issue with the device