I recently chatted with mastering engineer Ryan Smith at Sterling Sound in NYC. He mastered Beyonce's "Live at Roseland: Elements of 4," Iron Maiden's "Flight 666" DVD, and James Taylor's "One Man Band," so you can see he's a pretty versatile engineer. When he was a kid the sound of Michael Jackson's "Thriller" turned him around, and the first Guns 'n' Roses album made a big impression.
My first question was simply this, "Does the process start as soon as you hear the album for the first time?" If he's not cringing, he immediately starts to imagine how he would like the music to sound, and how he's going to make that happen. Sometimes, but not always, that might involve dynamic range compression, and Ryan said, "I might be thinking about what kind of impact is required, or it might be more about what sort of equalization would serve the music." If the mix is basically good Smith might want to just make it a little clearer or bigger, but he never wants to change the character of the sound. Smith stressed that's his approach, but some mastering engineers go further and put their stamp on the sound. He also feels the entire album should have a cohesive sound, but if it's a single, Smith might take another approach. Singles are treated differently than album tracks.
The producer or band might be very explicit, and say, "We want to sound like this band, or we didn't like the sound of our last record and now we want it to be more like this." Not all clients request additional compression; producer Perry Margouleff recently brought in a folk recording and he wasn't at all interested in maximum loudness. Smith finds he can lighten up on compression when he masters reissues of older recordings.
Each mastering session is unique, and Smith's first priority is to make his clients happy with the sound of their music. If Smith doesn't, for example, compress the music enough to satisfy the client, he might be asked to do it again, or worse, they might take the job to another mastering house. Smith seemed to think Mastered for iTunes is a good thing, and iTunes tracks sound a little better than they used to, but still not as good as a CD. The new mastering tools provide a preview of what the finished iTunes files will sound like. The iTunes master is a 24-bit/44.1 kHz file.
For now the best-sounding format most people will hear is still the CD, and that's where Ryan focuses his efforts. He started out as a recording engineer, but if he recorded something now, he'd bring it to another mastering engineer to get a fresh set of ears involved in the project.
He recently worked with another Sterling Sound engineer, Greg Calbi, on a forthcoming reissue of Paul Simon's "Graceland" LP. They used the original master tapes and compared the sound of the new master to original LP pressings, trying to make the new "Graceland" better than ever. That's what mastering is all about.