Hi, I read a lot and checked a lot, still recording result is too soft, with much white noise. I have included sample plus screenshot of Audacity+PulseAudioVulumeControl+Systeminfo made during the actual recording.
Soundcard Intel NM10/ICH7 Family High Definition Audio Controller works well, I have Mint 17.1 running, and have never had problems with sound. Audacity 2.0.5.
Why is the recording never ok, aways very very soft and noisy?
The blue waves with little or no sound are supposed to be at 0,0. Waves like yours are produced with damaged equipment. DC, Battery or Power Supply services are leaking into the sound. That’s probably where most of your hiss is coming from. It may be a bad soundcard or damaged USB microphone.
This kind of damage rarely happens after digitization, so it has to be in analog-land or just at the analog to digital conversion.
See my blue waves and 0.0 are the same. That’s normal.