Originally Posted by dkersten
Flat isn't always good as everyone has their own preference. Flat just means you are hearing it like the original sound editors wanted you to hear it. Many people like a lot more punch and a LOT more of the deep rumble, so they run their bass up 5-15db over flat.
I haven't see a lot of evidence this is true^ I have seen a lot of evidence that makes me believe people "THINK" that it is true, but reality is often they also don't know.
If you add 5-15db of midbass most would agree it won't sound great- especially the higher stuff. You get close the critical area where accuracy is preferred, and human hearing ability increases and becomes more acute- so smaller changes are perceived easier.
I'm nearly certain that if I went and dialed up +10db of midbass on anyone's system they would think it sounds worse. I used 10db because it's halfway between your 5-15db range you gave.
My understanding of what BASS is for clarity is all frequencies under the middle C on a piano. That is about 250hz or so, without my looking it up.
That gives you three ranges. The lower bass is the common sub woofer territory of 16-80hz. The mid bass starts above that and reaches to about 150hz, then you have upper bass which is 150-250hz. The definitions are confusing because midbass can mean the middle of the bass range, or it can be interpreted by some to be a half blend of bass and midrange- which really is more upper bass in the 150-400hz range if you take half of bass and half of midrange as your meaning. But clearly from 200hz and up I would say it sounds like midrange to many laymen, and if you polled people to guess what frequency it was, or call it bass or midbass, or midrange I am guessing 200hz+ would be guessed to be midrange because that is what it sounds like, and it's part of the vocal range.
The upper bass register is the most sensitive to SPL increases as hearing becomes more acute in that territory. Adding +10db from 150hz-250hz would not sound good IMO. It would be quite unbalanced, and sound unnatural. In the 80hz-150hz perhaps it might be more tolerable, and certainly below 80hz it becomes even more tolerable because as frequency drops so does your ability to hear it. Adding +10db at 20hz isn't generally a problem for sound quality- and it certainly provides you more of that pant flapping, house shaking aspect.
One point too- +10db has a dramatic increase on the required wattage so makes sure anyone trying to add big boost has a big amp and plenty of extra power.
But I would maintain that above 150hz, it's somewhat important to be relatively flat- and that will all sound there is always an element of balance. Someone who says midbass is lacking often has a room problem, so the sound is weak- a flat or slightly elevated midbass would be perceived to them as relatively more I think, because their problem is not that there is not enough, it's that it's being manipulated by the boundaries of the room.