Over-gassed 11.5.. cut to 10.5 help at all??

[MegademiC]

https://en.m.wikipedia.org/wiki/Choked_flow

https://en.m.wikipedia.org/wiki/Orifice_plate

From choked flow:

"The choked flow of gases is useful in many engineering applications because the mass flow rate is independent of the downstream pressure, and depends only on the temperature and pressure and hence the density of the gas on the upstream side of the restriction. Under choked conditions, valves and calibrated orifice plates can be used to produce a desired mass flow rate."

Thanks, I was specifically referring to the behavior of supersonic gasses, and the theory behind what causes them to slow down... or is that explained by the above and I'm just not getting it?