Albert,
I listened to the 6 pieces on your website and I’m of the opinion that you’ll never going to get these pieces to sound ‘good’. And neither will a pro engineer.
The problem isn’t so much the sound — the sound itself is actually not all that bad (I’ve heard much worse in pieces posted here on the forum) — the problem, in my opinion, is that you program and balance your instruments in ways which are so far removed from what a conditioned ear (which is what we’re all equipped with, I’m afraid) expects them to sound and behave like, that you’ve ended up with a near-continuous conflict between, on the one hand, the sampled instruments built-in aspiration towards realism (as solo instruments and as an ensemble), and, on the other hand, your complete disregard of that.
See, the moment you use a sampled bassoon, you create all kinds of expectations — expectations based on what people assume a bassoon to sound and behave like —, on top of the assumptions which a sampled bassoon itself already brings to the music. If you ignore all those expectations/assumptions and make the instrument behave in a way that is completely alien to its assumed identity, or if you balance it among other instruments in an equally unrealistic fashion, there’s no avoiding that the results will sound ‘jarring’. And ‘jarring’ is indeed how all your pieces sound. (I really like plenty of your ideas though.)
And that ‘jarring’ has got nothing to do with the EQ’s or the compression or the reverbs or whatever, it’s just that you treat your instruments in a manner they were never designed nor equipped to be treated as. Your approach tends to bring out the artificiality of the sounds and tools which you use, rather than hide it behind the veil of illusion which is so vital to the digestibility of a mock-up.
Two solutions: either you take this approach much further, until all remaining connections with reality are severed — which would be my choice, as it’ll give you a creative freedom, unshackled by mock-reality, which your music would very much welcome, I believe — or, you start again from scratch but this time observing much more how the instruments, which you use in simulated form, actually sound, behave and blend like in reality. Or, in other words: try to make a much more conventional and believable mock-up.
Either solution will solve a lot of what you, at the moment, consider to be mixing issues.
_