Hello everyone !
I have a special issue on my version of Sonar (X3)
When I record my voice, The results are normal but when I reload the file for editing, my voice is much lower than previously. It's not the first project where this issue happened. I don't know where it can come from but it makes my voice unusable.
 
Thank you !

It sounds as if you might have a weird samplerate mismatch. What interface are you using and which driver standard?

When you say "reload the file for editing" do you mean re-opening the SONAR project, or opening the .WAV file in another editor?
 
If it's all SONAR, take note of where the track and Master bus meters are peaking, numerically, in the first measure or two before save/close/re-open. If the meters read the same after re-opening, then something is messing with the output level of your interface when SONAR is closed. This is quite possible if it's the onboard PC sound system; less likely if it's a dedicated audio interface using ASIO drivers.