The activation method is a widely used technique to measure charged-particle induced cross sections for astrophysical applications. This two step technique is used for example to measure alpha-induced cross sections in γ-process related studies. The first step - in which a target is irradiated with a proton/alpha beam - is followed by the determination of the produced activity. Especially in p-process related studies in the heavier mass range, the produced radioactive nuclei decays mainly with electron-capture, resulting intense x-rays. The activity of the reaction products hence can be determine via the counting of these x-rays, and not only by counting the usually much weaker γ-rays. In this paper we compare the minimum detectable activity (MDA) of two High Purity Germanium (HPGe) detectors used for x- and γ-ray counting in activation experiments.