In a studio in Manhattan last Friday, Liev Schreiber was recording the narration of “Brooklyn Dodgers,” a two-part documentary that HBO will show on July 11. He was a few hours from heading uptown to the Longacre Theater, where he is starring in the Broadway revival of “Talk Radio” as Barry Champlain, an abrasive talk show host who loathes his listeners and is losing control of himself just as his program is being syndicated.

The lacerating tone he uses to animate Champlain is a characterization apart from his cool, elegant narrating, which has gone from a sidelight to a thriving second career.

In an ill-ventilated soundproof booth made stuffier by his cigarette, Mr. Schreiber read his “Dodgers” script from a music stand. “Ebbets Field is gone forever,” he said, recalling the team’s beloved little ballpark without sounding overly elegiac. “The men who played there are now ghosts in a place where once they were gods. But a half-century later after they vanished, the spirit of the ghosts of Flatbush endures in Brooklyn and far beyond. So, too, does one question: Why them?”

Two days later he would be in another Manhattan studio, narrating the third of four parts of “De La Hoya-Mayweather 24/7,” a behind-the-scenes documentary series that has followed the boxers Oscar De La Hoya and Floyd Mayweather Jr. in advance of their heavily marketed World Boxing Council junior middleweight title fight on Saturday in Las Vegas.