I doubt that B&O calibrated their sound setting indication to the levels of the 5500 when configuring the 7000. There are others here more knowledgeable than me on the topic, but I have owned both systems, and have both a Beomaster 6500 and 7000 now.
The 5500 was 2x60W at 8 Ohms; while the 7000 was rated at 2x110W. Which means there can be little doubt as to which was rated the most powerful - whether you ever use that power is doubtful. I have been running some very power hungry passive speakers from a 7000 with excellent results, which almost has me believing that B&O were conservative in rating the Beomaster 7000.
Both the 5500 and 7000 are very clean sounding amps - I think that if you ran both simultaneously, you would have little doubt that the 7000 packs a greater punch.
Do check the connection panel in the back of the 7000, and that the LINE OUT port has the proper stop in it. On mine this is the port at the bottom left of the connection panel, when you are looking at the rear of the unit. That should be plugged, with a special plug with leads in it.