Ten Bucks Theatre production of “Macbeth,” running through July 22 in the woodsy outdoor arena at Indian Trail Park in Brewer, reminds me of Julia Roberts. When she did her first Broadway show this year, everyone knew she brought a big dose of star power and beauty to the stage. But could she also bring the heft needed for live theater?

The two leads in “Macbeth” – Putnam Smith in the title role and Kat Johnson as his wife – give rise to a similar question. They are gorgeous individually and as a couple. They have proven themselves capable actors with a local track record. Yet somehow they aren’t quite right for the roles in this heavy-lifting tragedy about power gone awry.

Smith gets off to a moody start, and it’s hard to believe his “brave Macbeth” could slaughter a traitor from head to hip. Even his servant overpowers him vocally. Yet he goes all out in every way in the final combat scene. (It’s worth the wait.) But it takes a long time for him to conjure up that engaging action. Johnson looks so maiden-like – despite costumer Tamela Glenn’s flowing red robe dress – and spends so much time grasping her stomach, that it’s hard to take her Lady Macbeth’s surge of testosterone seriously. Frankly, I’d like to see her as Juliet and him as Hamlet. But that’s another story. Or two.

On the other hand, this is not a case of the leads dragging down a show, because each of them has resonating moments. And they both are easy in their roles. It’s just that one expects more potency from two of Shakespeare’s most fascinating, ambitious and flawed characters. It’s also entirely possible that these dark-haired beauties might have been more compelling had the microphone system functioned better. Too many lines were lost in static and sound dropouts on opening night. The frustration of trying to hear or catch up at times overwhelmed the performances.

Because of that, it is natural to be drawn to the actors with vocal power – Ron Lisnet as Duncan and a murderer, Arthur Morison as a porter and Ross, John Greenman as the doctor and a murderer, Josh Snowden as Malcolm. Emily Gammon, Jenny Hart and Starsha Schiller are surreally sexual in their writhing portrayals of the otherworldly witches, who, in one scene, recall the camp of “Ghostbusters.” They dash from behind Chez Cherry’s set of gray boulders (a la Stonehenge) like bugs on a ghastly but gamesome mission. Their flutterings are far more welcome than the actual bugs that keep the audience slappingly restless and spraying on OFF!

If you’ve seen past summer Shakespeare productions by Ten Bucks, then you’ll come away thinking director Julie Arnold Lisnet is pushing to take the theater to a new place with this show, particularly the second half, which rocks, so to speak. She captures the atmosphere of murderous mystery and is fearless about but never gratuitous with the physical and political bloodiness of this story. The lessons of Macbeth himself are a good reminder of the dangers of blind ambition – and Lisnet knows this but she doesn’t beat up the audience. “Macbeth” is Shakespeare’s shortest play but perhaps one of the more difficult for community theaters. Lisnet is to be admired for taking it on, and for taking it as far as she does. If you’ve liked what you’ve seen at Ten Bucks, you’ll be impressed with this piece.

Nevertheless, crackling mikes and irregular volume only reinforce the old superstition that “Macbeth” can be an unlucky play to stage. Ten Bucks can’t do anything about the bugs – so bring your own repellent and lots of it – but the creative team still needs to work out the maddening audio kinks in outdoor productions, which are so important to the greater Bangor-Brewer area. In the meantime, you can avoid being hobbled by this technical annoyance: Read the play. Then if a few words drop out in performance or a line gets lost when an ambulance goes blaring by, you’ll be able to fill in the blanks and you won’t have to wait until tomorrow and tomorrow and tomorrow to figure out the complicated plot.

Ten Bucks Theatre will present “Macbeth” at 8 p.m. July 20-22 at Indian Trail Park in Brewer. Tickets are $10 for adults, $5 for students. Bring chairs and blankets for festival seating.