Close-up: 50 Cent

Rapper and entrepreneur Curtis Jackson, better known as 50 Cent, recently became the latest recording artist to lend his name to a line of headphones—and one of the few to launch his own audio company.

Jackson's foray into audio equipment began last year, when he unveiled a line of headphones at the Consumer Electronics Show in Las Vegas. But before the headphones hit the market, Jackson cut ties with his partner, Sleek Audio, saying he was unhappy with the products' quality. "I didn't want to be part of a licensing agreement I didn't have control over," says Jackson, whose ventures include G-Unit Records and Street King energy drinks.

So Jackson started a company called SMS Audio and purchased headphone maker KonoAudio of Florida. This winter, he debuted his line of Street by 50 headphones, which cost $130 to $400 a pair.

To help the line stand apart from brands backed by hip-hop artists—most notably Beats by Dr. Dre and Soul by Ludacris—Jackson is targeting a wider audience. The thumping bass of Beats headphones is optimized for hip-hop, says Jackson, but SMS products are tuned to suit many genres.

Jackson is also pledging to donate a portion of sales to Feeding America, a charity that supports food banks. "If every company built a giveback program like this into its business model," he says, "it would really make a difference."