Subsonic Forum

Answer is yes - I am running both 4.6 & 4.7b3 on the same server.
But I am running on Windoze so cannot help further but I followed Glenn's (Bushmans) excellent guide
viewtopic.php?f=5&t=9226&p=44097&hilit=2+instances+of+subsonic#p44097
If you can adapt that for your OS then you are good to go

Can't you just run it as a different user, obviously with different ports, under Linux?

I've found that the simplest way to run multiple Subsonic instances on the same machine is to run standalone instances and pass parameters to define the new home directory and port numbers.
Example:
$ cd subsonic4.7-standalone
$ sudo ./subsonic.sh --home=/var/subsonic2 --port=4041 --max-memory=256

or to run it under a subsonic user account for security
$ sudo su -c "./subsonic.sh --home=/var/subsonic2 --port=4041 --max-memory=256" subsonic