We refer to these as split zip files. To unzip them, you first need to have all parts downloaded and in the same directory.
Generally, PSE will not provide download links for files larger than 3GB, because files of that size can often cause problems when you attempt to open them. However, many of our sound effects libraries are much larger than 3GB. As a result, we utilize a zip feature known as “volumes” (also known as a split or spanned archive). This allows us to deliver large libraries while keeping the inner folder hierarchy intact.
When zipping large amounts of data, we use archiving software to split the large zip file into several volumes. Each volume has the same maximum size; once that size is reached for the first volume file, a new volume file is created. This process continues until all of the data has been compressed. For example, say you ordered a sound effects library for download 4.75GB in size. If we provided you with a single 4.75GB zip file, you would probably encounter problems when you attempted to open or unzip it (in fact, zip files of this size are impossible on 32-bit systems). Splitting the zip file into 1 GB volumes would circumvent this issue, and would look like this:
File Name Size
Library.zip.001 1 GB
Library.zip.002 1 GB
Library.zip.003 1 GB
Library.zip.004 1 GB
Library.zip.005 750 MB
Although zipping in this manner splits the zip file into smaller files, it is still technically a single zip archive (that is, it is not five individual zip files). To successfully unzip the archive, you will need all the files, and you should only attempt to unzip the first volume (the file ending in .zip.001). Your zip program will automatically recombine the volumes and unzip everything at once. Zipping data in this manner is still considered lossless compression, so all of your data will be intact in its original form.
Mac OS X:
Unfortunately, the zip utility that is built into OS X cannot unzip split archives. To unzip split archives with OS X, we recommend Keka File Archiver Utility. This free utility is relatively simple to use and can uncompress files in several formats. To unzip the example above, double-click on the Library.zip.001 file after you’ve installed Keka. The Linux p7zip command line program is also available for OS X (see below).
Unfortunately, the zip utility that is built into Windows cannot unzip split archives. To unzip split archives with Windows, we recommend 7-Zip Utility. This free utility is relatively simple to use and can compress and uncompress files in a wide variety of formats. To unzip the example above, you can right-click on the Library.zip.001 file (after you’ve installed 7-Zip), select the 7-Zip menu, and then choose one of the “extract” options.
To unzip split archives under Linux, we recommend the p7zip utility. This command line utility is included by default in many flavors of Linux, and is available as an RPM package. To unzip the example above, you would use the following command:
user[at]localhost ~ $ 7za x Library.zip.001
The ‘x’ option will extract the archive while maintaining full paths. To learn more about the 7za command, review the 7za man page as well as the shared documentation installed by the package. It’s quite extensive.