It's hard to give you an exact answer without knowing more. It could be a combination of factors.

In terms of the harshness, what setup do you have outside the box? That is, mic, preamp, sound card, monitors. A shotty component could be your problem. When you finish a mix, do you try it on other systems? Your mix needs to translate everywhere and this might help.

In terms of creating space, it's awesome that this is a priority for you. But, think of this as an aim from the very start. Arrange your parts to try and suit the illusion you're trying to create. Have an idea of where the guitar will sit before you record, then adust your tone on the amp to suit. Similarly, move a synth up or down an octave, play your chords higher, etc. before messing with eq's to create space. I was lucky enough to play with some (digitalised) queen masters at a mates studio recently, and i swear, you move the faders up and it was almost completely mixed. A good band will mix themselves.

Anyway, much of this might have been completely irrelevant to you, but check your signal path for issues, get good moniting if you don't, and mix your tracks before you record them through tone and arrangement.

Also, I am the Stig.
I'm gonna go listen to Steely Dan now.

As far as equipment.....

Access Virus Indigo
Nord Modular G1 x2
Loads of VSTi
Neumann TLM-103
Summit Audio 2BA-221
RME DIGI96
M Audio Delta 1010
Mexi Strat
Mexi P Bass
Ibanez AFT75td
Korg Prophecy
Live 6
Cubase SX3

Now, I really don't think the problem is in the signal chain. More than anything else I'm starting to think it's a problem with sound choices. I gravitate to sounds that could be leads in themselves. Maybe that's a symptom of being a keyboard player first and foremost and wanting every instrument to "show up". I notice that ALOT of sounds occupy the same register and when I address this by dropping 12 I never get a satisfactory impact from the sound...even if I simplify it and sub the lost lower register harmonics with a different sound pitched an octave up. Eventually the lead key parts and the vox and or guitar are beating my ears to death by the time the hats join in. Im exaggerating, it's probably only 2db here or there but it's still cause for alarm. I really like what I've been able to secure in the low end and my kick/bass relationships have improved dramatically in the last year...

But when I ref my tracks, on any system, they don't translate like I want them to. All of them seem metallic in a way and not for a lack of dynamics...that's a tiger I think I've tamed. Fatiguing, brash, overly-hyped. THAT'S my problem. And it's difficult to overcome considering I subscribe to the church of substractive eq and have a deep-rooted fear of exciters and Waves C4 comps.

A large problem is that you are a big believer in "subtractive" equalization. You are subtracting too much. In fact, try it without any equalization. It's all in the balance of the mix, not the equalization. Many of my mixes are sans equalization. You select the proper microphones placed at the proper places and that's all the equalization you need. If your instruments are largely DI'd, you may need to program your sounds differently. You obviously have quality gear. Lay off the equalization, please. We don't all need parametric equalizers like George Massenburg. My Neve 3115's as equalizers as stupidly simple as the 1073's. And while they sound great, I'm happiest most of the time with hardly any use of them at all. They are there to enhance as opposed to correct for sound problems. So I rarely use them to the extreme. Tastes great. Less filling. Tastes great. Less filling.

Burp
Ms. Remy Ann David

I'll try that Remy. Correct me if I misunderstood, but the gist of that was "Get it right at the source. End game." Right?

Since everything except vox is recorded direct I have to create space for each instrument to exist in. I dont have the luxury of micing up cabs and experimenting with mic placements. Maybe my verbs are too shiny? Maybe the amp sims I choose in Guitar Rig are too aggressive? I don't cut alot out of the high end. Usually I high pass everything except bass and kick around 100hz and subtract slightly from between 1k and 4k with a tight Q depending on the unpleasantness. It's very rare that I have loads of upper mid and high end frequencies reduced. But, I find it's necessary to gently slope off some of the high end of the synth basses and tame the electronic drums with a dose of parametric eq just to keep things on the level. Still, though, I seem to constantly build up judicious amounts of sameness around 700hz-2k. Thats a total guess by the way but isn't far off the mark. Soloed the lowend is banging right as it should. But with all buttons on the "sheen" of everything else steals the show. Not acceptable.

This might be a good argument for "re-amping". Your DI recordings of synthetic material may be too rich in its harmonic content? Feeding some of those tracks out to a guitar/keyboard amplifier & putting a microphone on that to rerecord back into your DAW, might just be the ticket for your problems. And the microphone should be nothing more than a SM57 without any need for a boutique preamp. I keep telling people that they don't need 20-20,000 in frequency response on everything. That's counterproductive. Even though you are equalizing to create space, you are not creating a more natural environment for your sound. Heck, you don't even need a guitar amplifier to do this. But you don't want a wide range speaker either. A battery-operated pig-nose might be really groovy to use. Groovy meaning cool, hip, keen & all that modern jargon. What you are really say is that you need something more organic sounding. So throwing in a little old-fashioned acoustic coupling of microphone to Speaker between some air molecules will benefit you more than playing with equalization. Think about it then try it.

I like air molecules in my recordings
Ms. Remy Ann David

That's a great idea. Gonna try that tonight with a 58 and my little 15watt guitar amp. I think you're on to something with the comment about there being too much harmonic content in the synth passes.

MOST synth sounds are way too rich in harmonics. They are good for solo or leading instruments but when you start putting several in an arrangement then they get in each others way.

The source is everything.

And the arrangement.

Multiple layers of the same notes with different sounds is going to show up at the mix as problems here and problems there.

Unless you are writing orchestral arrangements that play in counter harmony and counter rhythm to each other. Its here that these large hamonic synths can operate on their own. A Yes, or a Kansas, or a Gentle Giant kind of arrangement can support these big sounds because the various counters leave room for them.

If you are supporting voice with chordal synth sounds and you are using a lot of them together, you are going to always have a struggle with each part being clearly delineated over another.

So, a change at the source.....a serious look at the purpose of a particular sound in an arrangement....a simplification of the arrangement...an approach to mixing which doesnt involve solo'ng any track but to simply bring it all up at once and start leaving out parts that may sound cool on their own but detract from the purpose of the song....

These are all things that will move you one step closer to perfection.

You mentioned AJA. Really listen to the arrangement of the sounds. Its lush and full...sure...its also really simply constructed with every part having its own arrangement space regardless of the type of sound it is.

And then its played to perfection by really good musicians who know exactly how much emphasis to place on the notes. And the notes...ie:quarter,half,whole,and all segments of the beat are so finely spaced. Lots of room if you really study it.

I've spent the day with a project that I couldn't really get the mix quite right on. It never felt solid or rich...always just sort of wispy here and washy there. Since it's a pretty poppy dance-oriented track there is no sellin that.

So. Left the faders where they were. Bypass all channel eqs. Bypass all channel compression. Bypass brickwall limiter on the master bus.

Pressed play.

Wow. My levels were a WRECK. The vocal was all over the place, the drums were disjointed, the bass was blubbering at best. Really a shock.

I deleted all my automation, removed all channel eq and comp, put everything up level and started paying attention.

Pulling down all the "ornamental" tracks and leaving the meat and potatoes, revealed alot of good, interesting harmonic relationships that I'd previously worked REALLY HARD to remove by using eq just to give certain tracks a little pocket to showcase within. I had 8db gutted on the vocal group at 400hz! And another HP at 200! And was hipassing the FM7 lead keys at 500hz! The Access Indigo bassline was carved to the point of nearly being just a sub. To make room for a really shitty sounding drumkit, I suppose. It went on and on like that. The snare was compressed and boosted to cut through....what? All the crashing sheen I'd just created by removing the entire middle of the spectrum on the whole track?

The mistake I commonly make, for whatever reason, is to start compressing drums and cutting here and there to make room for things that aren't even needing the space yet. Somewhere along the way I developed a habit of "guessing" where eq cuts need to go to make room for other sounds to poke through. I've been doing it over and over and over. Bass, 30hz down-cut 24db. Cut some more where the kick is gonna be. I haven't chosen the kick yet! But I fell into a routine of mixing this way and it made the task SO much more convoluted and frustrating as the process unfolded.

Today, working on this pain-in-the-ass project finally yielded a very nice piece of work. All I had to do was remove all the things I preemptively did to fix all the problems I assumed I would encounter and instead listen to what was really there. That's really easy. In the end, I removed about 12 unnecessary equalizers, nearly as many compressors and only had to introduce a sidechain comp to keep things bubbly in the lowend.

Careful level control, panning, verb and very very small amount carefully placed eq was all it took.

Thanks Remy and Dave.

I figured you were a good Sport. I mean, I figured you were good, Sport. That is to say, Sport, I figured you were good.

Yeah, LESS IS MORE & KEEPING IT SIMPLE STUPID, is stupidly simple. I mean, I'm a simple stupid. That is to say, I'm stupid enough to be simple. Or, something to that effect, or not to affect an effect? Either way.... Look! A chicken! But I digest.

I laugh & joke & tell people, "I'm the laziest engineer I know". That's because, I'm stupid. It's that simple. I do less. That's why I get paid, sometimes. But what really works best with clients, is when you turn a knob that does absolutely nothing and their response is "that's perfect", is my favorite. Not like using the "suck" knob in the Gary Larson cartoon, which you already experienced firsthand.

So? Can we hear it now?
Ms. Remy Ann David

I'm so glad it's simple to be stupid. Even more glad that stupid simply works.