Hi Rifruf. I bought a similar Acer last month as a replacement for my previous Acer, which up till the end had been trouble free for years. The new one had problems with the audio, the microphone being live at all times (annoying when you have headphones on) and also getting a loud intermittent buzz through the speakers/phones when watching video or playing music. The a/v system would also freeze mid play! I found a solution on an Acer forum which recommended installing the latest version of the BIOS. This can be found, along with the instructions, on the Acer support website. Not a hard job and seems to have cured any issues so far.
Acer are known for such problems with their latest products.