The Pack A.D. packs a lot of sound

It’s no surprise to learn that the two members of the Pack A.D. embrace simplicity in their songwriting, or that the Vancouver, B.C., duo’s elemental brand of rock ‘n’ roll comes about through on-the-fly improvisation. But when guitarist Becky Black and drummer Maya Miller went into the studio to record their sixth album, “Positive Thinking,” they were more prepared than they’d ever been.

“We took a lot more time recording this album,” Miller said. “It’s not that we didn’t put care into the former albums. It’s just that we had so much touring going on that we left ourselves very little time to focus on the in-between.

“In one way, it’s good, because you get that quick inspiration and just go with it. But it was nice this time around to do it from a different approach. … This time around, we were very thorough about going about and having lyrics ready for the studio. Usually I’m doing a mad scramble, writing lyrics while (Becky’s) in recording another song. It felt nice to have it together sooner than later.”

Miller and Black have been playing as a duo for 10 years, and their current tour makes its way to the Bartlett on Tuesday. The Pack A.D.’s music invites obvious comparisons to other thumping rock duos – the White Stripes, the Black Keys, Death from Above 1979 – with Black’s purring growl and Miller’s driving rhythms producing so much sonic power that you hardly notice there are only two musicians onstage.

“I don’t think there was ever a point where we tried to get someone else involved,” Miller said. “I think it was intentional when we started, and then it just became forgetfulness. We never pursued anyone else. It just seemed easier to just meet up to practice and come up with stuff. … There was talk that there might be a chance we’d bring another player along to supplement some things, but it still hasn’t happened.”

In the decade that Black and Miller have been playing together, they’ve developed a chemistry that allows them to capture spontaneity on tape.

“We rarely find ourselves on opposite pages with a song,” Miller said. “We’re just really used to working with each other. … We generally get together to jam things out. Becky brings riffs and melodies that she’s come up with and recorded on her phone, and I’ll put a drum beat to them. Or I’ll start a beat and she’ll come up with something on the spot.”

Miller says “Positive Thinking,” the band’s sixth studio LP, is musically and thematically darker than its predecessor, 2014’s “Do Not Engage.” She describes it as a stylistic extension of the band’s 2011 album “Unpersons,” which is probably its sparsest, fuzziest and most punk-influenced record.

“I think we tried some things on (‘Do Not Engage’) that ended up going more toward the pop side of the spectrum,” Miller said, “and with this one, we reined that back in. And there are darker themes running through this album.”

You’ll be able to hear some of the Pack A.D.’s yet-unreleased songs at the band’s Bartlett set. The dozen tracks on “Positive Thinking,” which hits record store shelves Aug. 12, are more indebted to post-punk and trippy psych rock than anything on “Do Not Engage.”

Miller says there’s a more obvious thematic tissue linking these songs together: She and Black took lyrical inspiration from their own social anxieties, their frustrations over corporate proliferation and their love of Dan Simmons’ novel “The Terror,” a fictional retelling of a doomed Arctic expedition.

“A number of the songs are touching on depression and how you deal with it day to day,” Miller said. “It’s a weird time to be on this planet, thinking we deserve it.”