The Beatles released 1+ last week, a new collection that, most notably, includes dozens of rare music videos the band recorded over the years. But tucked away behind the two Blu-ray discs is a revamped version of 1, the 2000 compilation that features all 27 of the Fab Four’s No. 1 hits. Don’t ignore that disc. When the team behind 1+ decided to polish up the video clips, it decided to also remix the songs on 1 — and tapped Giles Martin, the son of esteemed Beatles producer George Martin, to head up the job.

“They still sound like the songs you love,” Martin tells EW. “It’s just that if you go back to the original, you should prefer what we’ve done. When you hear them you feel closer to the band than you ever did before.”

The motivation behind the project is mostly technological. As Martin began to assist with fixing up the audio tracks for the 1+ video clips, he realized that his goal of making them “more immersive” should also apply to 1. While modern remastering efforts — most recently the 2009 reissuing of the band’s entire catalog — cleaned up the audio, none truly optimized the recording for modern, high-definition sound systems.

“You have to understand, the original Beatles mixes were designed for mono playback,” Martin explains. “The stereos that we all know and love were done very, very quickly. The band was never present when the stereos were made.”

Martin’s mission was to pretend the Beatles were in the room with him and tailor 1‘s iconic hits for cutting-edge stereos — no easy task when you know the audience for your work will likely examine it with a fine-toothed comb. “My approach was to be respectful of everything,” the producer says. “I had sessions and sessions where I flipped between previously remastered stereos, the mono remasters, and the remixes we’ve done. I flip between everything and make sure I prefer what we’ve done.”

But honoring the past didn’t mean Martin refused to make necessary changes. Consider “Paperback Writer.” The band only recorded one and a half takes of the classic song — “I couldn’t believe it when I looked at the tapes,” Martin says — and the session’s spontaneity comes through on the recording. But Martin also heard a “layer of stuff” that’s not on the raw tapes. The problem mainly stemmed from an ill-conceived stereo mix he says was created just “for the sake of being stereo.” It isolated the band on one side, the bass on the other side, and the vocals in the center, even when the song “sounds better in our world coming out of two speakers.” By returning some of its elements to mono, Martin restored the “visceral feeling” that he thinks the band intended.

The fresh edition of 1 also improves the band’s famed recordings in ways the 2009 reissue project didn’t. “It’s vastly different,” Martin says. “The remasters went back to these final mix tapes and remastered them. They cleaned them up and then they EQ-ed them and released them. What we’re doing is remixing. We’re going not to the final mix, we’re creating our own mixes.”

That explains why Martin performed the same procedure on audio tracks from the Blu-ray discs that don’t appear on 1. He’s most proud of his work on “Strawberry Fields Forever,” which had much of its studio wizardry wiped away on previous stereo mixes. “It has this mellotron pulse that in the mono version goes under the vocal and sounds really cool,” Martin says. “It sounds much more intense to me, it sounds claustrophobic in a strange way. That’s what John would’ve wanted.” The original stereo mix isolated the mellotron pulse to the right-hand side, and couldn’t be repaired by the surface-level edits made in previous remastering projects.

“It has the feel of the mono, but it’s in stereo,” Martin says of the new version. “It sounds stronger, like it has a spine to it. Fans of the Beatles say you have to listen to the monos, but nobody’s going to do that. Only the fans are going to do that. I’m trying to create that attention to detail in a stereo format.”