Want to send audio from one RPI to another over my network using sox. therefore need to run ssh without password. How to do this on a simple way?
You can achieve that by using ssh-keys.
ssh-keygen -t rsa -b 4096 on your client (your first RPI) and follow the instructions. Leave the passphrase empty.
Then copy the public key to your second RPI by running:
ssh-copy-id -i ~/.ssh/id_rsa.pub pi@secondRPI
Now you should be able to login without any password.