SEDs for simulations with black hole masses similar to M87 (blue curves, HIGH-mass) and SgrA* (orange curves, LOW-mass) for SIM20 with the same accretion rate. The three vertical lines correspond to 86 GHz, 230 GHz, and 345 GHz, respectively. The figure also marks the optically thin and optically thicker regions of the thermal synchrotron which lie on the right and left sides of the thermal synchrotron peak marked by the red diamond.