An operating point model has been proposed to determine dependence of output on the head-to-medium spacing in a single-pole head and CoCr/NiFe double-layer medium system. We studied this dependence for various CoCr thicknesses and compared the experimental results with the analysis using this model. For each medium, the linear dependence changed at a specific spacing. Magnetic flux density at the operating point is proportional to permeance factor, P_r and P_r/(1+P_r) as the spacing changes. The theoretical values agreed well with experiments.