Don’t let the protective plastic fool you: Rodrigo y Gabriela are metalheads.

Without vocals, distortion pedals or even a drum kit, Rodrigo y Gabriela whip sold-out arenas into a frenzy using just two acoustic guitars. Rodrigo Sanchez’s fancy fretwork may be reminiscent of flamenco, but the driving beat laid down by Gabriela Quintero unmasks the duo’s major inspiration: heavy metal.

“We are big Metallica fans,” she says. “Also Pantera, Megadeth, Slayer, Anthrax.”

Sanchez and Quintero began their musical collaboration in the early 1990s, as part of a Mexican metal band called Tierra Acida. After a record deal fell through, the two sold their amplifiers and pedals and moved to Ireland. They made a living playing covers of their favorite bands’ songs, with Sanchez on lead guitar and Quintero filling in for the drums and bass with her signature percussive guitar style.

As their popularity grew, the pair began composing their own music and recorded several critically acclaimed albums. Their most recent album, “Area 52,” showcased the duo alongside a 13-piece Cuban orchestra. Working with the Cuban musicians, plus collaborating with composer Henry Jackman on the soundtrack for “Puss in Boots,” inspired Quintero to return to her melodic roots.

“I remembered that I love to play arpeggios and melodies and solos and bass lines, not always percussion,” she says. “I started playing guitar again.”

Rodrigo y Gabriela are now trying out new songs with greater melodic contributions by Quintero, and they plan to record these new compositions in September, Quintero says. Though she enjoyed working with other musicians, she’s excited to return to the basics: just Rodrigo y Gabriela and two acoustic guitars.

Stripping down their songs “shows that acoustic music has a power to captivate a whole rock audience,” Quintero says. “Guitar is such a noble instrument; you can play it in so many different ways.”

For her, that means varying degrees of fast and furious. On past tours, her fingers would swell up like sausages from all of the thrumming, but these days, she avoids injury by plunging her hands into ice water after every gig.

“I do a lot of warming up before going on stage and some massages afterwards,” she says. “It’s like running a marathon.”

Music Center at Strathmore, 5301 Tuckerman Lane, North Bethesda; Sun., 7 p.m. $58-$68; 301-581-5100. (Grosvenor-Strathmore)