If you feel this is a mistake or your post should be allowed, please send the moderators a message. Re: Loopback for Mac? The 127.0.0.1 is a loopback (self) address and that is why the router is not accepting that. Loopback makes it easy to pass audio between applications on your Mac. If you're using a VPN it may mess with the crack too, try disabling it. power of Loopback, it's easy to pass audio from one application to another. There are more than 10 alternatives to Loopback for various platforms. When you open Loopback, the home menu appears. The utility Soundflower got some brand recognition among music and audio nerds after its introduction way back in 2004, and it does still have people working on support. The most liked alternative is VB-Audio VoiceMeeter, which is free.Other great apps like Loopback are Soundflower (Free, Open Source), JACK … Loopback pipes audio around for you.