Can King Lear survive a monarch-sized hole at its center? The Quintessence Theatre Group production playing at the Sedgwick Theater through April 20 grapples with that question, as a critical piece of miscasting threatens to crater Shakespeare’s greatest tragedy.

Robert Jason Jackson, an unnecessarily imported actor from the Midwest, brings little more than a sonorous basso profundo to the hubristic ruler. Those who like to hear Shakespeare’s poetry intoned mellifluously will delight in his velvety timbre, but if you long to connect with Lear’s emotional journey, you might find yourself, like the old king, lost in the wilderness.

Jackson’s Lear remains remarkably sane and placid from first to last. He seems certain of his decision to cleave his kingdom into thirds and divide it among his daughters, as he should in that moment. But as his tether from reality progressively loosens, Jackson keeps an even keel, which results in a long and bland evening. (The production runs nearly 3½ hours.) Don’t expect a dark night of the soul, or even a momentary black cloud.

In recent years, Quintessence has presented some of the finest senior actors in Philadelphia: Frank X and Johnnie Hobbs Jr. in a brilliant Waiting for Godot; Dan Kern as the cantankerous professor in Uncle Vanya; Paul Hebron as both the preening Tyrone of Long Day’s Journey into Night and the broken Old Ekdal in The Wild Duck. It seems a waste to bring in a ringer when any one of those local gents could have delivered a more compelling performance.

It’s a shame, too, because director Alexander Burns assembles an unusually strong supporting cast. It will come as no surprise that J Hernandez continues to burnish his reputation as the region’s premier classical actor with his cunningly malevolent turn as Edmund, the scheming bastard son of the Earl of Gloucester (commanding, sympathetic E. Ashley Izard, in a sharp bit of gender-swapped casting). Or that Gregory Isaac, unrecognizable from his suave turn in Lantern Theater Company’s Betrayal, makes a dignified, earthy Kent.

Goneril and Regan come across not as cartoonish villains but as forces to be reckoned with in blazing performances by Donnie Hammond and Anita Holland, respectively. Eunice Akinola wrests Cordelia from wet-blanket territory with forthright clarity.

Burns — who also designed the striking minimalist sets and intrusive soundtrack — isn’t immune to bad ideas. He imagines the Fool (played here by a grating D.J. Gleason) as a cross between Buster Keaton and a borscht belt schlockmeister. His staging takes a peripatetic approach, moving the action — and the audience — throughout the Sedgwick at various intervals. This choice adds little more than chaos and confusion to the proceedings. The phrase herding cats comes to mind.

If you seek a fully satisfying Lear, you may need to turn to another Jackson — Oscar-winner Glenda, whose own interpretation opens on Broadway next week.

Theater

King Lear

Through April 20 at Quintessence Theatre Group, Sedgwick Theater, 7137 Germantown Avenue. Tickets: $15-35. Information: 215-987-4450; quintessencetheatre.org.