“In Stereo” is a romantic dramedy in which a broken-up couple, David and Brenda, spend much of the film in separate universes of self-involvement. There’s a germ of a good idea here, but it would have been nice to have a “David and Brenda” section at the front end, or least a more substantial preamble, so that we got more invested in this couple. Perhaps director Mel Rodriguez is trying to make us feel the confusion and disorientation of these New Yorkers as they struggle in a world where a romantic connection is getting harder to find. Whatever he’s doing, we can’t help but feel that key moments of the story are missing. [...] the film gets interesting late in the game, when Brenda and David go to David’s place after the opening of his photography exhibit. [...] even then, the fun possibilities get squandered, and we are treated to a head-scratching ending that is more befitting of “All My Children” than a feature film.