Since their modest beginnings as four guys who drove around southern California with their gear in their cars, practicing wherever they could steal a space, Cold War Kids have always exhibited two qualities in their music: intense passion and emotional truth.

Lithe and percussive, roaring and tuneful, the soul-punk on the Long Beach quartet’s first two albums “Robbers & Cowards” (2006) and “Loyalty to Loyalty” (2008) emerged like miniature gothic novels. Singer Nathan Willett channeled taut dramas of men on the edge, families in peril, and crises of faith. The musical literature of these four tight-knit friends — Willett, Jonnie Russell, Matt Maust and Matt Aveiro — was a sound that augured something bigger, something more universal.

Now, that “something” has arrived in “Mine Is Yours,” the quartet’s third album for Downtown Records, due for release on January 25, 2011.

More intimate than anything Cold War Kids have done to date, the new album is a collection of songs dealing with the push and pull of human relationships, the glue that holds them together, and the equilibrium they sometimes find. “Mine Is Yours” finds the foursome at their most sonically potent, and Willett at his most revealing and vulnerable.

“These are portraits of relationships and commitment — what is holding these things together and what does it all mean?” the singer says. “A lot has happened in the last two years — long tours, marriage, relationships, people going different directions. I felt the need to be more personal, to show the many sides of me.”

That urge came at a critical time for the band, who harbored a fierce independence from the days they were making songs in a Fullerton apartment, recording them raw, and playing them in claustrophobic Los Angeles clubs. Their DIY ethic engendered an innate distrust of anyone outside their inner circle, but, as Willett and his mates came to realize after “Loyalty to Loyalty,” it may have limited them creatively too. “I remember thinking that if ‘Loyalty’ is the last record we do, I’d be disappointed,” Willett says. “It was a step, but I thought, ‘We have to be about something bigger.’”

Cold War Kids also wrestled with the notion that being “indie” is somehow antithetical to being ambitious — that wanting to make music on a larger scale can compromise one as an artist.

“But if you and your friends are just sitting back and speculating in the abstract about what compromise is or isn’t, you’re not doing anything, are you? You need to be in the moment. Our band started from a thousand hours of late-night drinking talking about what it would be like to do this. But you don’t want to be an eternal student. There have been a bunch of great indie bands in recent years that have earned deserved success, and they got there by going for it.”

This led Cold War Kids to work for the first time with an outside producer, Jacquire King. King, who has worked with the likes of Tom Waits, Kings of Leon, Norah Jones and Modest Mouse, produced “Mine Is Yours” over the course of two sessions in Nashville and Los Angeles. During these sessions, they expanded on the quartet’s signature sound while keeping intact its minimalist elements.

“It’s a more produced record with more textures, but it still sounds like us,” Willett says. “Overall, there’s just a broader sonic palette.”

Working with King turned out to be a revelatory experience. “We needed somebody we could fight with a little bit, in a respectful way,” Willett says. “On the first two albums, we really had nobody saying, ‘What if you tried this?’ If somebody asks you ‘Why is this a certain way?’ and you don’t have a good answer, and you have to rethink it, that’s a good thing. We ended up having a pretty easy relationship. He was more of a listener and a reactor.”

The result is Cold War Kids’ most fully formed music to date, an album they only imagined they could have made back in the days of their guerilla practices and late-night conversations. Passion and honesty — “Mine Is Yours.”