Bit: How did I miss this?! Sheesh! Glad I caught it before it faded into the abyss! Agree with Shad's comments, Bit. That's the only thing I sort of found "subjective" on this really. The mix is solid...completely audible, great performances etc.
I don't think the answer is "aggressive compression". My first thoughts are:
1. You're either stripping away too many good mids that are making things smaller...
2. You may need to select different instruments that come out of the gate with a larger sound size.
For example, if you don't mind me ripping things apart? I'd never "rip" you...no worries....I mean, systematically talking about each instrument. :)
Drums: They seem to be the smallest. The drums are just sort of there. No beef/meat/impact in the actual sizes of this particular drum kit. Again, maybe you're playing it too conservative and are stripping away too much mid range? Kick drum is border line acceptable. I hear some thumpage...could allow a little more.
Bass: sounds like it's a midi bass, correct? If you haven't already Bit, try that SI-Bass plug in Sonar. Honest when I tell ya, if you work that thing a little bit, you can make the bass so realistic you won't be able to tell it's not real. That plug alone made X1 (oh, wait, you don't have X1...shoot) worth the purchase for me for times when I don't have access to my bass or just don't feel like playing real bass.
That said, the bass sounds pretty decent low end wise and has enough percussive high energy in it. With a lower thrusted kick drum, it would take things over the top. When the instruments back down though, the kick and bass compliment each other nicely. When the rest of the music comes back though, we seem to lose the low end impact.
Guitars: I'd not touch a thing. The biggest offenders in this mix to me are the lack of size in the vocals, drums and bass. These guitars are definitely thick enough and doing their job.
Vocals: Great performance and use of effects. Again, to me a bit too small like you're removing too much good beef.
Other backing instruments: No problems there.
In my opinion, this is a nice balanced mix that a mastering engineer would have a good time with as you've left enough room for sculpting without over-doing anything. However, a little thickening in the core instrumentation and vocals would be where I would start first before you attempt to fix things via mastering.
Loved the song though and think it has mad potential to be a production monster with the right stuff added. It just lacks fullness. Like Shad said, it's not a separation or effect fullness that it's lacking...it's instrument size. You get that size by selecting the right instrumentation that has a big sound coming out of the gate. I have a few students that are experiencing this same thing. Spending a few bucks on some really good drum modules cures this most of the time and you get less robotic hits with the good ones because they give you more samples per velocity in each sample pool. I know...sometimes we have to make due with what we have...especially in this economy, but the above is where I would at least start.
You probably have some bigger sound sources in your immense library of sounds. I'd try there first and see how you fair then do a comparisson. You still did a fine job on this though brother....sound size is nothing to be concerned about really other than if you are comparing your stuff to national releases. I think you will fair well with either bigger sound sources or putting in some good low mids/mids to thicken things up. Sometimes we get so lost with trying to remove subs and low mid/mid mud we over-remove it. That may be the case here. Hope this helps...nothing but love and respect brother. Nice job!
-Danny