Hey Pat,
Just to clarify, the EQ in iTunes is just to manage what's already in the file...you aren't doing a mixdown of separate instrumental tracks, just the range of frequency's from the mp3, wav, AAC, AIFF, or whatever format you got running with iTunes. I buy CD's too, download to sample here and there, but mostly like to own a collection in retail form. As for my vocal settings, I tend to lower them that much because it reduces dead noise(crackle/fuzz)...and good metal doesn't need unintentional noise, it makes enough of its own. Vocals seem to be able to take the hit harder, as far as adjusting the EQ goes. By lowering the 7th below the middle(50%) mark, I find it makes the overall feel of the album sound like it's recorded in a vacuum, devoid of disruption....and I feel like I'm there too! I haven't heard a cd yet that the vocals died as a result of lowering it to the 20-50% range.
Granted our forum's venue here, I'll throw a Demonoid example out. Wargods is the song. The riff at 1:53 and again at the outro happens to be one of my favourite strings of sound I've ever heard. Natually I wanted to hear it as rich as possible. It all comes down to personal preference, of course, but 'Personally' I've found these following settings a great way to boost the CD as a whole. Using said riff as a demo try this, and toggle it on and off:
1st(32) -- Around 3rd-4th notch down.
2nd(64) -- Little higher than the previous.
3rd(125) -- Same as the first.
4th(250) -- Almost cranked, mybe first notch down.
5th(500) -- Same as previous, maybe little lower.
6th(1K) -- Dead middle(default)
7th(2K) -- 4th line from the bottom.
8th(4K) -- 3rd notch down.
9th(8K) -- Around the same as last.
10th(16K) -- Same again.
And...sweetly enough, while I still have my ordered copy of the ROTA CD, if you were to burn is off with these settings and play in a generic cd player, you'll still hear a world of difference. Just my 2cents...hope it's actually helpful for some people, as this simple run-around worked wonders for my music life.