First, what does "double-down" really mean? To me, it means if an amp clips at say 100 watts into 8 ohms with 1.0%, then it would test at 200 watts into 4 ohms, with the same distortion. I was under the impression that only amps like big boulder monoblocks can really do this. Even some amps that "spec" doubling into 4 ohms, don't show it a lab test...ie, Classe monoblocks down to their 40lb cav-75 75x6 amp. Can someone point to/show me links to lab tests with amp doubling into 4 ohms?