Hi Danni,
With all due respect, your interest in playback correction systems just started making a lot more sense.
Mixing down there makes it difficult to hear a balance of the frequencies. The 77dBSPL to 85dBSPL range, described all the way back in the early 1970s, is where the phenomena described by Fletcher Munson curves begins to balance out and you get adequate bass response without turning up the low end EQ. If you get much louder the high end gets too loud and you'll probably mix that too low.
That's the range where most folks perceive a balanced frequency response.
That's why the theater business identified that range as the target range and suggested that consistency in that range would provide a quality experience to people where ever they are. The reason theater presentation has been a good guide is that the audience doesn't get to turn volume knobs or EQ... so you have to do your best to provide something enjoyable. (I know, I know... a lot of theaters play back too loud and some just sound suck ass).
It has been recognized for so long that speaker designers target that range as well and make sure the cross overs or bi amp designs seem balanced in there. If they design a speaker to sound full range without supplementary EQ at 70dBSPL it will sound like boomy dog doo at 85dBSPL.
If you mix down at 70dBSPL, I think it is fair to say that you
need EQ correction to craft a mix that translates.
You can see that 90 has nice flat low end... but that's too loud for just about everyone to work at for very long without losing their ability to sort out the details. 90dBSPL may be great for the party but tedious for mixing.
all the best,
mike
edited