Last time I shared about our mtx sledhammer single 12 box in the jeep liberty we got it up to 140.6 db at 46 hz 141.8 db at 44 hz so far on my meter still with no boost at idle and 142.2 db at 2000 rpm and the meter could be up to 2 db low so a pontential 144.2db on 600 watts rms on a stock mtx box...voltage drop only drops to 12.6 to 12.8 volts at which is our best hit frequency with that box.....I also found out that spl best hit frequencies can change at maximum volumes so low volume testing may not be accurate in some cases....thought id pass that on