FileSalvage is a file recovery utility created for Mac users who wish to easily restore the data they accidentally deleted from their computers. The application enables you to recover files from various models of storage devices, restores a wide variety of file formats, and immediately scans the selected drives or folders.
On the left side of the screen you will find a list containing all available drives (internal and external) as well as an option to select a folder for the scanning process. In my testing, the program took a small amount of time to scan the contents of a 150GB drive and immediately displayed the found data.
You can preview the found files before launching the recovery process. Furthermore, the application is capable of locating bad sectors on your drives.
The one thing that bothers me is that you cannot restore any of the found files if you're using the trial version of the application. You need to register the program in order to recover any data. Hence, you can't be 100% sure this utility will actually restore deleted files on your Mac.
Taking into consideration the aforementioned aspect plus the fact that it's a bit pricey, I think you should try a different file recovery tool on your Mac.