I used to do custom audio work in high school and college years ago.
I entered a local crank it up contest and got booted for running modified equipment in the modified and unlimited class. There sound measuring devices said I had far more power than what my amp specs said I should have. Plus they were the ones that pointed out most of what You read below!
I sat in the parking lot with my windows down and walked all over several of the high end cars with name brand everything and crappy actual sound quality.
I had people ask me why I was not competing? They said my sound quality was very nice. Well balanced smooth and rich yet loud at the same time. The pro cars were loud but distorted and just not that pleasing to the ear.
I told them they booted me from the unlimited and modified class for knowing how physics works! It went agianst their rules. Plus I didnt have my car covered in peel and stick "steal my stuff" stickers.
I had many "experts" tell me running my amps with zero gauge welder cable for the power supply end will burn them out because its not fine enough stranded cable or because its not properly polarized!
And that running my free air rated subs free air will make them fall apart? plus the size of the box does not determine a subwoofers acoustical resonant frequency, the wattage of the amplifier does. Free air uses the whole trunk for the box.
And that running 12 gauge speaker cable from my amps (18 inches away) will cause so much power loss the amps will overheat or burn out. Plus if its not properly polarized the electrons cant flow in the right direction and will back up and cause wire fires!
I had several "audio experts" tell me I need sound ramping devices so that if I turn it up all the way from dead off my speakers will fly apart Because they need to get moving gradualy.
Also I was told time and time again that an amplifier can only do what its rated for no matter how much you modify it. Raising the rail voltage 50% and changing the output devices to run at 6 times their factory designed current limits and modifying the feed back, protection circuitry, and power supply to handle that change wont do anything because that number on the case determines everything, The factory lable determines what its capable of not how its built or been rebuilt!
To bad I was only 19 at the time.