*** 1/2 out of *****

Canadian indie-pop sisters Tegan and Sara show signs of maturity on the duo’s sixth album, Sainthood.

Coproduced by Chris Walla of Death Cab for Cutie, the album is an attempt to graduate into thicker territory, proving that a new post-punk sound can make plain repetition vastly intelligent.

Tegan and Sara Quin are twins who burst onto the Canadian music scene 10 years ago with intricate, jittery harmonies. Since then, the sisters have kept listeners interested with self-written tunes of emotional longing and lovelorn delusion.

Most of Sainthood keeps with the women’s anxious, romance-soaked themes. In fact, Sainthood borrows its name from the lyrics of a Leonard Cohen song “Came So Far For Beauty.” The only difference between Sainthood and 2007’s The Con (also produced by Walla), is that these themes are now woven into a pattern of much heavier synth and jarring guitar.

In Sainthood fourth track, “On Directing”, the women sing, “I know it turns you off when I get talking like a teen.” But for many Tegan and Sara fans, “talking like a teen” seems to be the appeal — what they do so well is to dip themselves in a vat of nuanced, angsty love lyrics that sound like a frantic conversation.

This sort of distraught dialogue is evident in such tracks as “Arrow.” Listening to female expression of quiet turmoil amid a quivering synthesizer practically makes the listener break into a cold sweat.

Likewise, “Don’t Rush” rolls engaging lyrics along a heavy bass line. The duo switches to a lighter, catchier mood in tracks such as “Someday” and “Alligator.”

There are a few tracks on which the attempt at sounding more mature seems as if the women are trying to fit into metal-toed boots far too big for their feet. Such is the case in “Nightwatch,” where heavy lyrics such as “I deserve this anguish on my house” clash against inconsistent background noise.

The parts of the album that work are those that push that infatuated, sometimes delusional love. T he songs that don’t resonate are the tracks that exile both emotions and choppy guitar licks into corners far too deep.

Ultimately, Tegan and Sara grab us again with sounds of devotion and distress — and if this was Sainthood’s intent, then the women are martyrs for their cause.