Noise Level Peaks question

I am writing a report about an investigation into a clubs audio system. I have gathered the results using Rightmark, the measurements were taken with a Behringher ECM8000. I am stuck upon understanding why there are at peaks at roughly 650Hz and again around the 10KHz region.

The system configuration and the graph showing the results are attached.

Any help we be appreciated.

Cheers Stu

Those graphs mean nothing without the physical dimensions of the room and every object in it.