Japandroids guitarist Brian King, left, and drummer David Prowse sit still a second.

It may seem that not much has changed since Japandroids released their first album, “Post-Nothing,” in 2009. Guitarist Brian King and drummer David Prowse recorded their second record, “Celebration Rock,” in the same Vancouver studio, with the same equipment, the same engineer and the same less-is-more attitude. The band’s sound — loud, anthemic rock ’n’ roll — remains largely unchanged. Even the album covers are nearly identical.

In reality, much happened to King and Prowse in the four years since recording their debut. The band almost broke up, King was sidelined for months with a perforated ulcer, and yet, most importantly, the duo still played more than 200 shows.

“We’ve just gotten way better at playing our instruments, and we’re considerably better at playing with each other,” King says. “On top of that, we gained a lot more confidence in ourselves … We thought, if we just went [into the studio] and did the same thing, same methodology, same technology … we would inherently just come out with something better.”

Indeed, “Celebration Rock” is much more polished and focused than the first record, yet it retains the same energy and unbridled enthusiasm. Even though it’s only 35 minutes long with just eight songs, the album feels big — much louder and more expansive than you’d expect from a group of only two. “You’re just hearing a band tangibly get better,” King says.

“Post-Nothing” was “about being stuck in one place [Vancouver] and wanting to get out,” King says. The new album is “about getting out, because we did. It’s a ‘this is what happened and you should [try it] too’ kind of thing.”

As for the title, “Celebration Rock” seemed like an obvious fit to King.

“I couldn’t think of a more apt description — not just of the songs and the album, but of the band as a whole and coming to see us play,” King says. “We’re a rock ’n’ roll band. The kind of rock ’n’ roll we play is very celebratory.”

The disc even cues listeners to pick up on that festive feel: The sound of fireworks opens and closes the record.

Rock and Roll Hotel, 1353 H St. NE; Sat., 8 p.m., sold out; 202-388-7625.