This is my first post here, so it may as well be audio-related, seeing as I too make 100% of my living in that world (Multi-Grammy engineer, 2 x Cinema Audio Society winner, 1 x TEC Award, blah blah blah). Also not meant to brag, just meant to say that I haven't seen the sun in almost 30 years, lol. Not until I got my P3D+, that is.
mswlogo - Your graph is pretty close to how my ears hear my system. The bass is a little bloated and the upper frequencies lack a little clarity. It's all minor, though. It should also be noted that the ECM8000 has a 3db rise at about 8k, which means the Model 3's upper frequencies are even a little less present than your graph indicates (unless your software compensates for the mic's rise, which I don't know). A slight bump in the upper frequencies (talking no more than 2.5db or so, explained why below) and possibly a tiny reduction in Low Mids to reduce boxiness cleans up the overall sound pretty well. In all honesty, the system right out of the box is VERY good and I usually just leave it flat, as designed. I was very pleasantly surprised when I played my usual test tracks (read: almost anything mixed by Bob Clearmountain, Hugh Padgham or Nigel Godrich, plus some of my own stuff as well just because).
I think spending any money to tweak this system is a waste and will in most cases make things worse. The only possible exception might be the strategic use of Dynamat, but only then if you have money to burn. I have $800k in audio equipment and won't spend one thin dime upgrading the audio in my Model 3. I'm satisfied.
Hecdog - I would agree with your observation that there is a lack of clarity in the low-mids, but I believe it's due to a little bit of frequency crowding. This is why I think a slight reduction in the low mids might be an improvement.
Also, I would respectfully suggest that there are a few reasons why you might not want to boost all frequency bands as much as you have. For one, doing so is not simply a flat increase of the overall output by 8db, nor does the overall EQ remain steady when doing so. One reason is that fundamentally, as with any amplifier, an increase in gain equals an increase in noise. The bigger issue for me is that, unless this is a linear phase EQ (which I'm sure it isn't), you will introduce phase anomalies when you boost across multiple bands. This is especially true when using broadband EQs with fixed, non-adaptive Qs, such as the Model 3's 5-band EQ. I start to hear phase shifting at about 3.5db of boost in my P3D+, which is why I'd boost highs no more than +2.5db (if I'm hearing them at +3.5db, they are certainly happening sooner than that). Phase anomalies are sometimes OK if you're EQing individual tracks within a mix, but they will certainly be destructive across a full mix.
Now, is phase shift on a mix necessarily wrong? No. Will most people hear it? No. Is it necessarily wrong to boost that much? Of course not. Just saying that if your goal is to faithfully reproduce the material as cleanly as possible, I'd suggest not over-boosting. I'm definitely a graduate of the so-called "subtractive EQ" school of mixing. Having said all that, if it sounds good, who cares what's right or wrong? Do what sounds good to you. To paraphrase the famous engineer Tom Lord-Alge: "The EQ goes to +8db for a reason. Use it!" (his original quote referred to the +15db on the SSL, but it works here).
But happy to move to PM too.
