Audio Volume Issues

[Apachat]

Hello,

I'm currently using W7 64 as host, and W7 64 for the VM, software version 4.2.12 r84980.

The microphone volume captured by the VM is very low, however it's fine at host level. Even by using the sound boosting options in both sides it's still insufficient. Given the OS chosen, the only option is the Intel HD Audio, the other options just don't work.
I don't know why it's behaving like that. It was a fresh install, so I believe it has to do with the VM software.
Is there any fix for my issue? Maybe a more recent update?
Will updating affect my currently configured VM images?

[Apachat]

I've test if the VM has a different input frequency from host, both are at Stereo 16 bits 44100Hz. Still haven't figured out a possible solution for this.