CB11 making massive .cpr and .bak files with SL7 Pro in action

Only working on a small project here, but I find that each project file .cpr and backup .bak is almost a gigabyte when using SL7Pro on the project.

Is this expected behaviour?

Considering that Cubase will happily make dozens of backups of your project, this is going to become very large very quickly! :open_mouth:

If it is by design, then that is fine, but I thought I’d just ask as recently there was a problem withe Arturia VSTis also making large cpr files while storing unnecessary stuff in the .cpr file - that is now fixed after an update.

I can confirm this. I just checked a project I have been working with in C11, and each saved version of the project is above 1 GB in size, including the bak files. Let’s hope that this is not by design.


SL is an audio data editor, therefore any modification you do is going to be saved as raw audio data within the project file (as recommended by the ARA specifications).
That being said, we’re looking for options to reduce the size of those projects. I understand Cubase doing backup of projects can become problematic when your project becomes big, maybe having the possibility to externalize SL’s audio edits could help in that case, avoiding redundancy.

Hi Robin,

It would be fantastic if you could optimise these file sizes in Cubase. In my workflow, I regularly save incremental versions of the cpr, so say one track/song goes to version nr 20, that means a lot of gigabytes for just that track. It would be great if the raw audio data you mention could be saved just once for each project, as indeed is how Cubase handles audio data.

Meanwhile, would it be safe to delete previous versions of incrmenentally saved cprs to save space? Or would this affect the audio data in the latest cpr?

All the best,


You can safely delete previous versions of your cprs, everything SL needs is saved in each cpr.

Great! Good to know.

Many thanks,


Thanks for the information.

I’m just alarmed that this was only a simple project, and then I ran a daily backup and was surprised to see it backing up multiple GB of data for what was a 1 track SL7 practise project.

Seems too unweildy. Optimisations would be very welcome.