This applies to CuBase Pro 10.5.
Problem
"I recorded and everything sounded fine. Then when I exported my song and played the file through another audio device, it sounded lower pitch and slower".
Discussion
By default, Cubase will create new projects at 44.1kHz (the old CD sample rate). Often, recording interfaces are set to higher rates... sometimes we record at 48kHz on a Behringer XR18 to match the video standards.
The problem being, if the CuBase Project sample rate does not match the recording interface sample rate - everything will sound OK when using the interface... but when listening to it through other devices (like your PC speakers) - it will sound a lower pitch and have a slower tempo (8.125% slower).
What has happened is that CuBase will have stamped the wrong sample rate in the audio file metadata. This is bad news. But all is not lost.
You can change the metadata sample rate using a tool like Wavelab - but then it can get confusing regarding sample and event positions.
On the upside - you can fix this, post, within CuBase Pro with the resampling process.
Solution - Fix with Cubase
If your recording clips do not all start together then you will need to create stem tracks. The spacings between clips on a track will get messed up and timing will get stuffed up during the conversion. So by working with stems ... the relative timings between clips will be locked in.
If each track is just a single clip and they all start together, then you don't need to create the stems.
So before your conversion, you want to be working with all tracks starting together like this...
Next, change the CuBase Project sample rate to that of your recording device. If my project rate was 44.1kHz and my recording device was at 48kHz, I would change this setting to 48kHz. Audio > Project Settings...
Then click these...
So you are now working with the correct sample rate. The audio will still sound lower pitched and slow at this point, but at least everything should be in time.
So now we are ready to resample those recordings to get them sounding good. Select the audio clips and use these settings....
Audio > Processes > Resample
Solution - Fix with Wavelab
Open up the audio with Wavelab.
Under File - you will see the Sample Rate set to 44 100Hz. This is what CuBase thought it was... but that was wrong. It was actually recorded at whatever your interface was set to - that probably being 48000Hz.
So in here...
Set to this and hit "Apply Changes"...
The WAv file will now play higher - to to correct pitch.