values are nominal and since music is a constant changing signal, the impedence values that an amp sees is hardly ever just the stated speaker ohm value. What RF is saying is that when you hook up a 4 ohm load to a bridged circut, your seeing a nominal value of a 2 ohm load. With your stealthbox you would see a nominal value of 1.5. From my experience I have never really seen a well built modern amp have any issues with a set up like this as long as your not maxing out the amp all the time for extended periods of time and even then some amps don't flutter. Go for it and if worse comes to worse and it gives you problems get an Accumatch and be done with it.