Editing Dbx (noise reduction) (section)

==dbx for program delivery via the American NPR Public Radio Satellite System ==

The first generation [[Public Radio Satellite System]] (PRSS), introduced in 1979 and used by the American [[National Public Radio]] for delivery of network programming to their member stations via satellite, was a [[single channel per carrier]] (SCPC) system that had about 40&nbsp;dB of analog (recovered) signal to noise. dbx modules that were set for 3:1 were used to increase the dynamic range of the system. Typically this worked well but for some low frequencies the distortion exceeded 10 percent THD. Also the dbx modules varied in how they tracked the compressed audio so the expanded audio was not an exact representation of what was compressed at the uplink. Still, the use of dbx allowed NPR to be known for its high fidelity standards on its satellite system as commercial broadcasters chose NPR to up-link a number of commercial radio music programs and concerts by commercial radio networks who demanded high fidelity in the analog era. Many of these problems were resolved when the PRSS moved to their second-generation system in 1994, the SOSS (Satellite Operations Support System), in which the feeds were sent digitally.