Figure 3: Yoke Mount Drilling Dimensions - NorthStar 951X Installation Manual

SECTION TWO - Installing the unit
Whether you're flush- or yoke-mounting the unit, allow at least 2½-inch
Flush and
clearance at the rear for cables and connectors. For yoke mounting, leave
yoke-mounting
ample room (usually two inches) all around the sides and top to avoid
crowding the unit. For the recommended drilling dimensions, see
Figure 3 below. Before drilling holes, rotate the unit to the desired angle
to ensure proper clearance for cables and operation of the unit.

Figure 3: Yoke mount drilling dimensions

951/952 INSTALLATION MANUAL Revision B Page 11