We report an experimental protocol for measuring the frequency dependence of the bulk modulus carried out in a synchrotron x-ray facility based multi-anvil high-pressure apparatus. An oscillating pressure perturbation characterized by x-ray diffraction produces a volume strain measured by imaging. Together, these yield the bulk modulus of the sample. Here, we report data at 3 mHz as an example of the possibility of providing these data for the frequency range of 1 mHz-100 mHz.