Hi Vlazyh,
Welcome to the Heartland Owners Forum. We have a great bunch of folks here with lots of information and all willing to share their knowledge when needed.
I had a 3055RL and the radio/stero unit was in the cabinet behind the glass door above the desk. The speakers were mounted on the ceiling and the bass was in the bottom of the cabinet in the desk area. I don't have pictures, but maybe someone else will jump in with more info.
Enjoy the forum and check out the Heartland Owners Club.
Jim M