ventilation in stereo cabinet - advice?

I've picked up a new stereo cabinet and am concerned about ventilation.

Cabinet is approx 3' tall x 2' wide x 2 ' deep. Has a glass door at the front and two holes for wires at bottom (in the back).

Contains an RR2150 (at top), CD multi-changer (middle), and Apple Airport, surge protection, wires (bottom).

I've noticed that the ~3" gap above the RR2150 does get noticeably warmer than ambient if left running with the glass door closed.

I'm thinking of drilling a hole (or two) for ventilation at the top (in the back). Maybe adding a fan in there to move the air around.

Wondering if anyone had any guidance about their own cabinets and/or ventilation?

Thx.

A hole or two would help. The RR2150 is going to be your main heat source, so putting it at the top will help avoid dumping its heat across the associated devices. If you have some openings to allow airflow in (at the bottom) and out (at the top), that's a good place to start. A fan could be added later if necessary. I've also used a cheap indoor/outdoor digital thermometer to track temperatures in an equipment rack - most will remember the highest temperature recorded, so you can see just how hot it gets.

Two holes and much sawdust later ...

Thanks, Gonk. Great idea re: the thermometer. Have added that to the next shopping list.