使用PHP强制下载更大的外部文件

I want to force download larger files using PHP from an external domain. I tried lot of things (especially cURL) like How to protect a file on sub-domain of main site from download without auth in wordpress, How to force download of big files without using too much memory?, etc., but none working fine (either working fine for smaller files or if file exists in same domain). Can any one able to provide a solution?

Will mod_xsendfile work for this case (larger files from external domains)?