When uploading files in the browser the maximum file size is limited by server configuration. WP-Filebase does NOT have a file size limit!
To uploading larger files, the upload_max_filesize and post_max_size need to be increased in php.ini.
If your server configuration allows it you can add this line to your .htaccess:
php_value upload_max_filesize 30M
If you are on managed/shared hosting, ask your hosting provider to change these values!