BARNESVILLE, Ga. • Last fall, the Southeastern Conference announced something that, in these parts anyway, amounted to a seismic shift. The collegiate sports league said it was expanding, inviting two schools to join the fold.

One of them, however, the University of Missouri, stands to make the most noise.

Think sonic boom.

Mizzou is about to get a bass drum the size of a hotel hot tub.

The 9-foot-tall, 800-plus-pound instrument, thought to be the largest in the country, was built at a Barnesville machine shop by a Gordon College music instructor. It took him four months.

The builder, Neil Boumpani, his last name befitting of a percussionist, got a call last winter from a fraternity at Missouri. The school already had a 6-foot bass drum named "Big MO," but it wanted more "MO" to bang on at home football games.

Prominent drum companies turned them down. They found Boumpani on the Internet.

"We want a 9-foot base drum," they told Boumpani, who said, "Whoa," and then, "Let me think about it."

Boumpani, 55, a New Jersey native who directed the marching and pep bands at Duke University from 1987 until 2005, figured, "Why not?"

Purdue and Texas Tech have 8-foot drums, but as far as Boumpani knows, the only one larger is a 10-footer in China.

Boumpani's creation, which has cost close to $50,000 to make, has a fiberglass shell that was made from a custom mold in Alabama. An auto-body shop in Griffin, Ga., later painted it metallic-black. The plastic, 108-inch drum heads on either side cost $1,500 apiece. He plans to ship the drum to Missouri soon. But not before he records its low boom to remember it by.

Even so, he said, "This is not something you make for sound. It's more to ... aggravate the other team."