ok, i've tired the by ear and i don't like it at all because you have no sense at how much power your sub is seeing and like the guy above said he did it by ear and the amp was over half way up but by ddm it was at a quarter. i can turn my amp to full gain by ear and it sounds fine to me but i know its clipping like a mofo and my only turn my hu to 3/4 max volume never higher which is 35/50. i've tired the voltage coming from my rca's on the back at 50/50 volume head unit and sub 8/8 it reads 2v so if i only ever play at 3/4 volume with the sub set to 8/8 its probably only seeing 1.5v but that's on a sine wave and not music. figured the bashing will continue but in this case using a ddm subwoofer lvl on hu middle or max? and i don't have the need to get a o scope (more bashing on how i'm going to kill my eqiupment //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif) but not everyone has the access to every tool ever made.
Edit: also wouldn't tuning by ear find the clipping point of the amp? and not the max power the sub can take? Because my amp says i does 1500rms but im sure its only reall 1200rms clean and only want to give my sa12 1000rms clean so i would be overpowering my sub before i reach clipping on my amp? or the speaker distorts with too much power?