ok so I have 2 questions really why is it that sometimes when I play songs back after I’ve exported them the sound goes up and down? I’m mainly thinking guitar parts? they play fine but sometimes they just dropout of the mix then back in again and also why is it that during a project if I mute the bass tracks I can hear them fine but when all together I can’t(i’m getting a signal) I’ve tried uninstalling and re-installing cubase and i’ve also downloaded and run the updates? any ideas?
Maybe you need to check sample rate configuration for import files (after exporting a mix and trying to put it again in the project). If you don’t ask Cubase to convert them, (and they are different from the project), the imported files will sound different. But I am not sure if this is what you are asking.
The second question is about mixing. The sound of a instrument inside the mix is different of the same track alone. It is not a problem with the software, but a matter of understanding how a mix works. It is too complex to explain in a simple post.
yeah I know that but Iwhat i’ve done is deleted the track and moved it to a new one! 
thats kinda worked!
:-p