WPHI-FM, "Boom 107.9", is a radio station owned by Radio One, that airs a classic hip-hop format. The station is licensed to Pennsauken, New Jersey and serves the Philadelphia market. It has studios located in Bala Cynwyd and broadcasts from a transmitter spire on top of One Liberty Place in Center City Philadelphia.
The station originally operated as WSNJ-FM in Bridgeton, New Jersey, first broadcasting on 98.9 in the 1950s before moving to 107.7. In the early 2000s, the station's frequency and city of license were changed to allow it to move into the more lucrative Philadelphia market. To clear space on the FM band for the new operation, high school station WHHS was moved from 107.9 to 99.9 MHz and a Philadelphia translator of classical station WWFM was taken off the air. During transmitter testing, 107.9 used the call letters WPPZ and broadcast gospel music; owner Radio One eventually gave that call sign and format a permanent home in the market on 103.9 FM. Before WRNB went on the air in 2004, the call letters were used for a Radio One-owned sister station in Dayton, Ohio, now called WROU-FM.
On September 1, 2011, Radio One moved WRNB's programming to 100.3, and the Urban Contemporary format of WPHI-FM (which moved away from rhythmic contemporary earlier that year) moved to the weaker signal 107.9 FM as "Hot 107.9" (after stunting that weekend as "Michael Vick Radio" and "Rickey Smiley Radio") on September 4 at 5PM. The first song on Hot was Hot In Herre by Nelly.
On November 6, 2014, at 7 PM, WPHI dropped the "Hot" format and became the third classic hip-hop station in the United States (following KDAY/KDEY in Los Angeles and sister station KROI in Houston) as "Boom 107.9". The last song on "Hot" was I Like It by Sevyn Streeter, while the first song on "Boom" was 99 Problems by Jay-Z.