If not, find other software that can enhance.
If it does enhance, then it is possible:
2. The sound output signal of the tablet is not big enough, and the speakers can only amplify it to half of the USB flash drive. Find a larger volume than the flat panel, such as CD player, radio and so on, some cell phone volume output is also quite large. Try to see if the volume of the speaker gets louder?
3, if the sound is bigger than the tablet connected to the speaker, the sound is still half the size of the USB flash drive, it means that the speaker has a limitation or protection of the amplification of external sound, the maximum can only be half the size of the USB flash drive.