I was noticing how terribly my mixes suffered from playback in iTunes as compared to just playing back the file in a finder window, and I learned that the cause of that horrible sound was the "enhancer" in iTunes. I'm glad to have solved that problem, but I'm still left with this nagging question: Why did my mixes suffer so much more from the 'enhancer' than did the songs from some of the commercial CDs I own? This is really a broader question. I know I'm not using the finest equipment or plugins (I use the Logic plugins in the mix and PSP VW for finalising/"mastering"), and I know my monitoring equipment and room are nowhere near up to spec, but I've found that my mixes actually sound even better on pro monitors. They sound right. But then when I try them out on my two cheapo car stereos, they suffer so much more than commercial CDs do—huge peaks and valleys in the overall EQ that I just don't hear on my Radiohead or Badly Drawn Boy or Gillian Welch CDs? Is it too optimistic for me to hope that I could make my mixes as system-proof as these CDs? I try to take what I learn by hearing the mixes on junky systems into account, but I feel a bit like I'm chasing my tail. Also, as for volume. I read a lot of people on forums like this sneering at the notion of trying to up the volume of the final mix, but my ears keep telling me that even with a good deal of compression/limiting on my overall mix, my levels don't approach those of, say, Badly Drawn Boy's 'One Plus One is One,' which to my ears still sounds incredibly open and natural and dynamic. Am I supposed to believe that they're not using a ton of compression on their mix?