You’re about to buy an album on iTunes when you see that there’s a remastered version just below it. Surely something that’s "remastered" must be better, right? To adequately answer that question, you have to understand a far more basic query: what is mastering?

First, a little background. There are many tracks that comprise a song. The drums occupy several tracks, as do the vocals, along with the various other instruments. A recording engineer artfully mixes all those recorded tracks together to create the song. It’s all mixed down into two channels, left and right, which gives you a final stereo recording.

"Once that final mix is done, it’s done. Think of each track like a color of sand going into a jar," says Greg Milner, a journalist who writes about music and sound and author of Perfecting Sound Forever. "It’ll have layers of red, blue, and green, but you can’t separate or remove any of the individual colors. You’d have to start the filling process over. That rainbow-colored jar is the final mix."

Mastering engineers start with that final jar of sand, meaning they can’t change individual tracks. For example, they can’t make the vocals louder or the drums quieter. Pre-digital, the final mix was delivered on actual tape to which the mastering engineer applied final touches to make the recording pop and shine. "When mastering for vinyl, they make sure certain frequencies of the overall album weren’t too high or harsh. Aggressive frequencies can make the turntable’s stylus leap out of the record’s grooves," Milner explains.

For vinyl albums, you’re trying to add back the technical elements that were lost

Frequencies are important for vinyl because records spin at different speeds in the center than on the outside, so the high frequencies need to be adjusted so the album sounds the same from start to finish. Equalizing the length of side A and side B is vital. Longer sides mean more compromises. "Sometimes bass will be reduced to fit a longer side," says Bob Katz, a master engineer credited on more than 600 albums and owner of Digital Domain. "In the old days, they’d try to squeeze 20 or 30 minutes per side, so you’d have to lower the volume and the surface noise, and reduce the bass. Those things take up more physical space on the record."


When a mastering engineer was happy, the final master was transferred to analog tape used to press the master disc from which all other records were stamped. Then came CDs. "Early on, engineers didn’t know what they were doing with CDs," Milner laughs. "They used the same master tapes for vinyl and cassettes for CDs, but CDs need different processing." And now, with digital recordings, everything’s being recorded without an analog master, so the master itself is digital.


Some Girls (Remastered)

The Rolling Stones

Make sense so far? That brings us to remastering, which is redoing that whole process again. "Sometimes it works, like with ‘Some Girls’ by The Rolling Stones, remastered by Bob Ludwig, [who is] one of the best in the field. His version was vastly superior because it sounds cleaner, less harsh and brittle, and more nuanced." Milner pauses before adding, "though sometimes remastering is just gimmicky, used by people who don’t know what’s going into the process but thinks the marketing sounds good. Remastering isn’t always better."

Why would you want to remaster an album? "Maybe the first time, it was mastered for a CD but poorly and now they want to get it right," says Katz. For vinyl albums, you’re trying to add back the technical elements that were lost when the first record was pressed. "Older records in the Sixties and Seventies don’t have a ton of deep bass. To fit more on the album, they cut everything off at 40 or 50 hertz," explains Katz. "Audiophiles today are more critical, demanding a response down to 20Hz. It takes more skill to fit that low-end material on a record.” Other remastering reasons include the pitches were originally wrong, adjusting levels that weren’t perfect, and reducing noise. "If the original was hissy in an annoying way, we can reduce that without a sonic compromise," shares Katz.

As for how you remaster an album, the answer is: carefully. "Original analog tapes are delicate and can deteriorate with each play," Katz says. "Record companies are precious with original tapes so, to avoid the master eroding, usually everything is transferred to digital format, at high resolution, ideally 24bit/192khz. You then work from that digital file."

Thriller (Remastered)

Michael Jackson

Tweaks like adjusting the amount of compression come next. "Jazz and classical audiophiles have a knee jerk reaction against compression because it destroys the dynamics of the music," says Katz who has remastered the likes of Dizzy Gillespie and Wynton Marsalis. "Avoid adding too much where you lose the original recording’s snap and surprise factor, but an ideal amount of compression in pop or jazz or rock helps it sound punchy and powerful. There’s an optimal loudness where it sounds just right."

Louder isn’t always better. Michael Jackson’s Thriller was mastered at least four times and each succeeding time it was made louder. "The fourth remastering really sucks," says Katz. "Why would you mess up a well-engineered record? The loudness race. It’s self-defeating because no one wins it. Loudness adds distortion and fuzz, so it’s going to be worse."

If you’re buying new music, there’s no point to buying vinyl.

With much of our music being consumed digitally, the question becomes whether an artful remastering even matters. "With streaming services, not really," says Milner. "You’re hearing a data compression so much of the audio is stripped out." Katz agrees, noting that "over 90 percent of the time, remastering is pure hype on streaming services."

Spotify, iTunes, and Tidal don’t share a global standard of file parameters, so compression or equalization to optimize for one platform can sound off on another. "For the best sound everywhere, be conservative and level," says Katz. "For example, Spotify has loudness normalization that peak-limits albums to keep volume equal from album to album."


The Dark Side of the Moon (Remastered)

Pink Floyd

Digital audiophiles should get remastered albums from HD Tracks, where the ardent and skillful work of engineers like Katz can be appreciated, and sometimes sound superior to vinyl. "There are so many remasters of Dark Side of the Moon [and] the last few vinyl releases don’t sound as good as the HD Tracks version because the digital version came from the master tape when it was in better shape," says Katz.

As for separating remastering triumphs from the bullshit, Katz recommends perusing the Dynamic Range Loudness War database. This free website will show you how good—or bad—the dynamic range is on any version of most albums. If you’re looking for proof of that Thriller got worse over the remasterings, Katz suggests checking this out.

Maybe you’re reading this and concluding that you should revert to records, that vinyl reigns supreme. "For old stuff, absolutely," Katz says. "If you’re buying new music, there’s no point to buying vinyl. You can make new LPs, and I’ve done some for dance artists, but it’s a fad without much of a point. The original was recorded digitally, and never went to analog tapes. To get rich sound, you’d need to put no more than 17 minutes on one side, which means for a 45-minute album, you’d need three sides. If you’re a real audiophile, you’d want a 45 rpm disc, which would mean only one to two songs per side. Then again, there are some people out there who don’t seem to mind the masochistic tango of turning the LP over every song," Katz chuckles. "To each, their own."