You can also look on the back and see the model number of the receiver. HT-R560 goes with the 5100, HT-R580 goes with 5300.
The 5200 system uses the HT-R570 receiver which doesn't decode HDMI audio either like the 5100 receiver.
As far as the surround speakers, they're all sh!tty. Full range 3 1/4" driver only. Same speaker in all 3 systems, just in a different cabinet. I guess they had to change styles with each new model year.