Rimshot
Great info Danny!  I never knew that mixing engineers like to present a "flat" mix to the ME.  I never did that in my day but in today's digital markets, it does make sense to me the way you described it.  I think I will try that on my next song.  Try to mix flat and then do the color shaping in the mastering.  
 

Yeah Rimshot, try it out. It's definitely a cool way to work. You don't want to go too flat though. Flat was probably the wrong word. We want more of a neutral sound actually. But see how you fair.

In the big leagues of course, the producer has the vision, so most times if something is going to get pushed in the mix, he wanted it that way. But a lot of the times they are really going for a neutral sound that isn't over done. This way they can enhance things and really do it right. Even there during the mastering though, the producer is making all the decisions.

Even if you have Bob Ludwig mastering, the producer is going to at.least sketch a picture and then he may allow Bob to paint things his way due to his skill. But you never know. Some producers run the entire show based on their vision and stick to their guns. At the end of the day, everyone should have fun mixing and mastering on their own. You only really need it when you're going to sell an album in my opinion. :)

-Danny

Actually, in the "big leagues" the producer situation widely varies. In reality, there are a whole lot of variables involved. Here in the 21st century, the ecosystems have changed from the old school "big record label" mentality to more control to the artists. Thanks to the internet, artists are now more free to publish work to a wider audience as opposed to relying on a "record deal".  With that comes a change in the presentation medium. Yes there are still those stuck to vinyl and need "mastering". A vast majority of people listen to their music through crappy earbuds anyway. Few people, if any, will hear your music through studio grade precision monitors. I do agree with Danny though, that everyone should have fun mixing and mastering on their own.

Actually Pete, though what you say there has some merit, we're talking the big leagues. I doubt Beyonce or foo fighters master their own material even though they have control over their productions. Another thing to keep in mind, though it's possible and probably happens from time to time, it happens way less that people in our field are referencing home mastered stuff by people without a deal. I'm sure it happens, but less often.

Unfortunately I have to agree with you on the crappy listening experience of buds. I actually had a client ask me for two masters of their album to be included on their cd. One mastered on real monitors, the other through his personal preference of Sony ear buds and the mastered material needed to sound good and compensated for at 192 kb for mp3. Though this makes me cringe, I can see how someone would want something like this. It also made me a little.more cash and was a "different" experience to say the least.

-Danny

Danny Danzi
Unfortunately I have to agree with you on the crappy listening experience of buds. I actually had a client ask me for two masters of their album to be included on their cd. One mastered on real monitors, the other through his personal preference of Sony ear buds and the mastered material needed to sound good and compensated for at 192 kb for mp3. Though this makes me cringe, I can see how someone would want something like this. It also made me a little.more cash and was a "different" experience to say the least.

But this is the whole point of the mastering process... The consumers aren't listening to your stuff on your expensive monitors, they're listening on their ear buds, home "hifi" and car stereo.
The mastering process is intended to make that sound as close as possible to what you heard when you mixed it in your studio..

It is not intended to 'improve' your mix.

Some interesting perspective and food for thought here. :)
 
I have a busy day today but I thought I'd chime in just to address some points brought up by Danny, as to clarify my position.
 
The low cut at 40 seems arbitrary, and to a certain degree it is. I guess I was partially influenced to take the decision by some (maybe questionable) common wisdom. Other key factors were the genre (rockabilly/swing) and overall production feel I had in mind, and personal taste.
 
Furthermore, considering that my set up doesn't allow me to make an informed judgement on what's going on down there. The way the little mono set up in the gym reacted also gave me the impression that there was too much going on in the low frequencies.
 
240 dip: most of the stuff I listen to seem to have some kind of dip in that region compared to my own mixes. So it's not just the reference mix, which, to be honest, I didn't really attempt to duplicate. As a matter of fact, I simply played back a few passages to give me a feel, but didn't really analyze it. For all the reasons you mentioned.
 
Same for the high shelving. My own mixes tend to be very flat I guess. It always seems easier for me to  bring forth those frequencies later on than to try to get rid of any nasty side effect afterwards.
 
 
Ok. Wife's birthday - I must run.
But I'll be back! :)

There's also consumers that have high end systems and expect the quality of the music to match them. A big mistake is to assume ear buds, hifis and car stereos can't sound amazing. I can't see any mastering engineer worrying about how anything sounds outside his studio because he'll know it's perceived quality is a pure reflection of the system it's being monitored on by the consumer. If the client requests something specific then why the hell not.
If a record company asked me to submit them something in particular then I would ask an ME to do it for sure.

A point I want to make is that we as writers, engineers, and producers, want the best product we know how to get.  
I agree that for major commercial releases, choices will be different.  However, most of us are doing our best without having the option to engage ME's.  So we learn by doing and listening and try to get better at it in time.
 
As far as making your mix sound good on crappy earbuds, I don't go there.  I use good headphones, my studio speakers, and my car.  All of these have at least a decent dynamic range and frequency response.  
 
My son is 17 and he uses Dr. Dre's with his iPhone. My wife listens in her 2014 Nissan Altima which has a good stereo. Anyway, the point being that none of my family's playback systems are crappy and my mixes seem to hold up well on them.  That is all I can hope for at this stage of my career.
 
So to all that strive for getting better at this - more power to you and keep experimenting and learning.  It truly is a lifetime's work.
 
Rimshot
 

I think one misconception is that high end speakers like audiophile monitors "make" things sound better.  If they sound better it is because they are better drivers, but they are not forcing that sound through processing or design.  They will reveal more detail and make it easier to correct issues or weaknesses.  The better results will trickle down to consumer end listening devices.   That is one of the reasons you see mastering engineers use these high end audiophile loudspeakers with clean amplification rather than studio monitors.  The sound is no-compromise honesty and detail.  

As far as personal tastes are concerned, if I had the option, I'd probably buy the pre-master, flat mix version of most of the records I own. That's how I like my music.
 
For rock, I am no fan of modern mixes, where the entire spectrum of frequencies is filled to full capacity. Remove what's not essential instead of cramming as much as possible into it. I always feel like music nowadays leaves no room for the listener. It doesn't drag you in, it corners you and beats you into submission.
 
Me, I prefer albums which aren't as "produced". Paranoid by Sabbath, Physical Graffitti by Zeppelin, stuff like that. 
 
Or then, give me something like Moving Pictures by Rush - that's probably the most modern sounding, polished and produced album which I'm in awe of, in terms of balance and use of the frequency spectrum. For rock.
 
So at this point, I'm pretty happy with my mix, but I do realize that it sounds a little unpolished by post-1977 standards.
 
I wouldn't feel comfortable having it denatured into something too different, but I can see the point in making it a tiny bit less personal and taking it at least a couple of steps closer to certain references.
 
 

Here are a few of my thoughts.
 
1 Mixing and mastering are not the same thing and should not be done at the same time. They are very separate processes and should be treated so.
 
2 In the right hands mastering can just take a track up another level. Hard to describe. It is not a big mix fix either. I prefer mixes that are excellent to start with. It is something else again. It is that fine EQ tuning that just makes a track sound nicer and more well balanced across the spectrum. It is that very slight compressor conditioning that just adds a touch of pro evenness and leveling to a mix and it is that limiter which can just kick it up a notch in level without destroying the mix.
 
3 CakeAlexS is correct, MOST mastering engineers are very average and they routinely make most mixes worse by far.
 
4 Genre has a lot to do with how obvious great mastering is. In a classical situation it may be very subtle. In a pop or hip hop situation it can make or break a tune!
 
5 I would not hand over my track to a ME and not be there either. It is important to compare the unmastered sound to the mastered sound at exactly the same volume so the level shift or loudness thing is removed. Then what you hear is only how they have made your track sound worse! (or hopefully nicer)
 
6 Reference tracks are vital especially if they are right in the ball park of your style and music.
 
7 Mastering is a very delicate operation and the music is SO easily ruined or made worse. Most ME's are too heavy handed. And many pass the mix through way too many processes as well. It takes skill to actually make it nicer.