Costs and difficulties associated to testing can be an Achilles' heel for modern large-scale mixed-mode systems. Here, a low-overhead technique is introduced to enable the design of analog filters capable of checking their own parameters. The approach can also be applied to add such functionality to existing filter designs. The case of a switched-capacitor 2^nd order band-pass stage is used for illustration. The approach is based on the recently introduced complex oscillation based test methodology and permits to appreciate not just deviations in characteristic frequencies, but also the merit factor (and thus bandwidth and roll-off).