Wayne & Russell,
I can only respond based on my own experiences as of late. What Karsten is hearing is between his ears only. You both know darn well that as an engineer, I know all about A/B, blind listening and all the rest. Anybody got a spare $1M or so...we'll put together one for ya.
The fact is, your very livelihood (well, to some degree anyway) depends on your clients "trusting" you, your technical abilities and ultimately, your hearing. How many times have you botched something during a take that can't be re-done. You've had to "fix it in the mix" and, although you may have been sweating bullets, you did and your client never noticed. Whew...pulled that one off!
Don't tell me you haven't 'cause I've been there. If you've been working any length of time at all - it's happened. And the fact is, it's a testament to 2 things. First, your client's inexperience and second...your own hearing ability and talent. There isn't a professional on the planet that wouldn't consider your getting away with it as anything other than a feather in your cap.
Why? Because you knew what to do to fix it and had the
ability to hear the difference. You had just the right combination of hearing and talent to make something that would have been a tragedy...paletable. The odds are, you'll be the only one that ever knows too...unless you tell.
Now how is that? Why can you tell right where that mistake is and almost nobody else ever will? The answer is obvious on one level - you were the one that made the mistake. But...I'll bet you listened to that track dozens of times and made many adjustments before you were satisfied that it might pass by un-noticed by the public. Repetition is the key...listening over and over to the same thing. Sooner or later the brain locks in and figures it out.
Of course I'll be first to admit that with regards to frequency, hearing memory sucks. I had a Crown EQ2, 11-band
parametric EQ with high and low pass shelving AND with adjustable hinge points -at 18 years of age! You know the drill and I don't even want to think about all the wasted hours. I've mixed both live and studio sound, used/owned compressors, limiters, effects of all sorts - you name it. Why the heck do you think I built those darn Timepieces to begin with?!!! The same reason you bought them. They're MONITORS!!! It's only by a twist of fate that these audiophile guys even begin to get it.
But the one thing they DO have is the same as those of us that are experienced have OR ANYBODY HAS...ACUTE
DYNAMIC HEARING SENSITIVITY! You don't need a PHD from
http://www.fullsail.com/ to have a natural, in-born ability to hear subtle changes in dynamics. It's the dynamic changes that tell you a noise is the TV set or... someone dropped a glass in the kitchen...or broke a window and is coming to rape your wife and kill your children! We need it for survival and it is more acute than any other sense.
I guarantee your eyes don't have 120dB of resolution - neither does your sense of touch or taste or smell. You may be deaf beyond 8kHz but you can still tell if a sound is real or recorded. And it is in the
realm of micro-dynamics that the things Karsten and (now) I are hearing.
Specifically in my case - I'm lazy and the shop sucks to sit and listen in for very long. I don't have a system at home because my house is tore up from re-modeling. So...because I don't really care to spend all day out in the shop where it's almost always chilly and listen for hours on end (and don't have the time anyway) I listen to the same 2 discs over and over and over - every time and now it's been for years.
Those 2 discs are: Dianna Krall "Girl in the Other Room" and a CD that one of our first customers burnt for me. "Horsehead" made me a disc that has different cuts from David Grisman, Eleanor McEvoy, Nickel Creek, Diana Krall and even that famous Chinese Drum track (whatever their name is).
Yeah, once in a while I do a reality check on other stuff too - but I always go back to them. Why? Not because they're "perfect" and certainly not because I like them that much (in fact, I'm about as sick as you can get of them), but because doing so has made them "constants." If something changes - I hear it. Since almost forever I thought the Dianna Krall disc had an overloaded mic pre at times - the honk in her voice would get so bad. With the new "standard" crossover - "all gone." The FR is as flat as ever so don't even bother going there.
Then there's the issue of hearing brushes on drums - that's what they sound like now - distinct and separate from everything else rather than being "merged." I always thought that it was how they were miked before and "frequency masking/precedence" was at work. Same thing with voices...now I can count them individually...sounded like just a "massed chorus" before. When I'm hearing things on
those recordings that I
NEVER heard before, well...I'll be nice and NOT tell you what you can do with your ABX switch! I've ABX'd those recording until I'm nauseous.
So how's that coming from a "pro." Well, the only difference is that in the cornfields of Indiana, you can't make a living at it. But other than that, I use to be the guy every band in town called when they needed advice (for free of course). And I'm telling you other pros...this stuff is for real, it ain't a bunch of crap, I know enough to know what I'm hearing and I ain't deaf. How far you can go with it I don't know, but at this point I've heard enough to keep my mind open and not dismiss anything until I hear it for myself.
SO THERE!

That and 99 cents will get you a cup of coffee at Speedway.
-Bob
PS. I'm not beating up on you guys. I've been fighting with myself over this stuff for a while now. I'm biting my nails back to the bone waiting for the day I can prove it scientifically.