The quality of the original plug of Aiodi is also OK, and the analytical power is good.
Bass is not equal to good sound quality, low burn bass, medium burn voice, high fever burn high frequency, earphones to do low frequency is easy, high frequency, medium frequency is difficult to do.
Good sound quality should be three balanced, listening.
The ZVM is good, but what about the range? Durability? No need to belittle IAUDIO, my D2 thinks it's fine.
BBE is quite well adjusted, and it is wrong to use low frequency to determine the sound quality of the machine.
Recommended D2, can expand SD card, cost-effective