Irradiance measurements from the IPHIR instrument flown on the Phobos 2 mission to Mars are used to derive phase differences and gains between broadband relative irradiance signals and full-disk velocity variations for l = 0, 1, and 2 mode with order ranging from 12 to 32. These data are compared with contemporaneous measurements of photospheric velocities obtained during four intervals within the 155 d observation period of Phobos 2. It is found that the phase difference between irradiance at 500 nm and velocity is roughly constant with an average value of -119 +/- 3 deg from 2.5 mHz up to about 4.3 mHz with a slight increase suggested by data up to 4.6 mHz. The phase differences between the green and red channels do not differ significantly from zero below 2.8 mHz, while a small difference of about 13 +/- 5 deg exists at higher frequencies, with the red signal ahead of the green. This jump appears to coincide with a jump in the separation between the l = 0 and l = 2 eigenfrequencies.