Can I use both 64-bit and 32-bit versions of Reason on my 64-bit Mac OS X system?

Yes, you can!

On Mac OS X, the Reason application itself includes both 32-bit and 64-bit resources. This means the program will run in 32-bit or 64-bit depending on your operating system – you don’t actually need to do anything when installing the software.

It might be desirable to run the 32-bit version even under a 64-bit OS (for example if you’re using Reason with ReWire and a host that only supports 32-bit ReWire). In this case, you can force the program to run in 32-bit mode in the following way:

  1. Select the Reason application.
  2. Select “Get Info” from the File menu in Mac OS X.
  3. In the Info dialog, tick the “Open in 32-bit mode” checkbox.

When you now launch Reason it will run in 32 bit mode.