We present our analysis of a set of populations of massive black hole binaries generated in the recent semi-analytic model of galaxy evolution (SHARK). We focus on studying gravitational wave emission produced by these inspiraling binaries in terms of their detectability with current and future detectors, i.e. PTA (Pulsar Timing Array) and LISA (Laser Interferometer Space Antenna). The key advantage of SHARK is that it provides a way to explore a number of distinct models of black hole and galaxy evolution processes within a consistent framework and it was also successfully tested against EM observational data. In our work, we study 12 models varying in seed formation scenarios and test two different BH growth and feedback models. We show that all of the models fit well within current observational constraints on GWB and BH mass functions and that complementary LISA and PTA detections will be able improve our understanding of MBH and galaxy co-evolution processes.