Confused

[Jakeeck 10+ year member]

i had my gain at about 80-85%.. its from 9v-.2v.. i set it by ear.. but today i decided to set it by dmm with a 50 Hz test tone.. so i calculated that with 900w wired at 2 ohms i should be getting an output of 42.4v.. so i set my gain to 46v with the dmm

just hooked everything back up and it was a little quieter than before.. gain is at about 4.4-4.7v.. i have the output measured at 46v since i know you can set the gains higher with music than a test tone.. but can i still turn it up a little more?

and also.. when i calculated all of this with an online calculator my gain should have been at 2.36v in order to put out 900w with my hifonics 1208d wired at 2 ohms(see pic)

what could be affecting this? i had no load hooked up to the amp when i set my gain with the dmm but i read another thread on here saying that shouldnt matter..

sub is a 15" ia li.. deck is an eclipse cd3100 5v preout

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[PaulD 10+ year member]

when you use the calculator and DMM or oscope method, you are setting the gains so the amp will never clip. In reality, with real music it will clip about 10-20% of the time at med volume levels if the gains are set right. This is not bad and will not even be noticeable. All of this is assuming mid/tweet amps and speakers, for the subs you can clip them quite a bit more beforee it is noticeable.