Ted Roof making early impression with his high-energy style in his Georgia Tech homecoming

ATLANTA – Georgia Tech players use words like "high-energy" and "intense" to describe their first week with new defensive coordinator Ted Roof.

Roof described the opening of spring practice as a sweet homecoming.

Roof, who played linebacker at Georgia Tech from 1982-85, is back for his second stint as an assistant coach. He made his first return to his alma mater in 1998 as an assistant and then defensive coordinator.

Last year, Roof had success leading Penn State's defense in the wake of the Jerry Sandusky scandal and NCAA sanctions. Now he faces the challenge of reviving the Yellow Jackets' defense.

Roof's departure from Penn State surprised some observers. He says his homecoming was a perfect fit.

"It's home," Roof said. "It's all about family. I've got a lot of pride in this place and a lot of sweat equity. Some of my best friends in the world are Georgia Tech graduates and my family is here, so it made sense for a lot of reasons."

Roof's return also made sense for Georgia Tech, which was looking for defensive help after ranking 65th in the nation with its average of 28.29 points allowed per game in 2012.

Al Groh's term as defensive coordinator ended in the middle of his third season when he was fired midway through his third season last year. Charles Kelly had mixed success after he moved up as the interim coordinator, but he left in January to coach Florida State's linebackers.

Georgia Tech allowed 40 or more points in six games last season, including in a 42-10 loss to Georgia. The Yellow Jackets' best performance came in a 21-7 Sun Bowl victory over Southern Cal to cap a 7-7 season.

Groh couldn't make a 3-4 alignment fit the Yellow Jackets' talent. Roof is installing a 4-3 scheme.

He's also bringing a renewed emphasis on intensity.

"A lot of coaches are high-energy, but I definitely sense his energy and he's a very personable guy at the same time," said defensive lineman Euclid Cummings. "He has a great balance.

"His first message was that we're a high-energy team and we set the pace for the entire team. And we finish strong."

Roof, the Duke coach from 2004-07, has a history of bringing improvements in his stints as defensive coordinator at Auburn, Minnesota, Duke, Georgia Tech, Western Carolina and Massachusetts.

Roof led the defense on Auburn's 2010 national championship team. Duke ranked 113th of 115 teams in rushing defense in 2001, and in Roof's first season as coordinator in 2002 the Blue Devils led the Atlanta Coast Conference in stopping the run.

Penn State ranked second in the Big Ten with its average of 19.1 points allowed under Roof last season.

Roof coached under Bill O'Brien at Penn State. The two worked together on George O'Leary's Georgia Tech staff from 1998-2001.

Roof said he had a flash of nostalgia as he walked past fraternity and sorority houses on Georgia Tech's campus and he remembered "seeing girls laying out sunning and guys having fun throwing the Frisbee in the front yard."

"It was pretty neat," he said. "You think about 30 years ago and then you think about 15 years ago and then you think, man I used to walk a lot quicker."

But most of his thoughts are on bringing improvement to a defense which returns eight starters.

"This challenge is the same," Roof said. "It's our responsibility to put a product on the field that we can all be proud of."

Defensive end Emmanuel Dieke said "it's like a whole new culture" with Roof.

"It's been great," Dieke said. "We're learning a whole new scheme. It's like a whole new atmosphere with a lot of talk about intensity. It's a whole new feel."

Roof said he is using the spring practice to learn about his players while making sure his players learn what will be expected on game days.

"I'm passionate about our guys getting better," Roof said. "When you work like we work, I don't know how you can't bring energy if you're passionate about it.

"I've always tried to be enthusiastic about whatever I'm doing. I certainly believe the old adage about habits, if we want to be enthusiastic players, then we have to practice with enthusiasm. Game days are going to be a reflection of our habits."