Wheatstone Unveils New Multiplex Power Wizard
Wheatstone has announced its new Multiplex Power Wizard, a new feature for its FM-55 audio processor and SG-192 stereo generator that reduces or eliminates the undesirable audio effects usually associated with the restriction of multiplex (MPX) power to minimize adjacent channel interference.
The new feature is targeted at broadcasters in Europe and other regions where short-spaced FM frequencies necessitate the reduction of average RF sideband energy through restrictive MPX power control.
With this new feature, broadcasters will be able to keep multiplex power pegged up to the legal limit as set forth by the European ITU-R BS.412-7 modulation standard, but without objectionable processing artifacts such as gain swelling or gain pumping.
The Multiplex Power Wizard utilizes a program-dependent prediction, detection, and measurement algorithm that continuously adapts the multiplex power controller’s behavior to the incoming program content. The algorithm allows for the extremely tight multiplex power control desired by broadcasters, but without contributing noticeable or undesirable control-related audio artifacts.
“Multiplex power controllers add yet another layer of processing on top of what is already being done by the processor, but our philosophy is that an MPX power controller should be able to do an exemplary job of controlling MPX power, and do so without compromising a station’s sound,” says Jeff Keith, Wheatstone’s Senior Product Design Engineer.
Wheatstone’s new Multiplex Power Wizard incorporates new processing techniques that can tightly control multiplex power without affecting audio quality. The Wizard’s location in the signal path permits it to be aware of audio power increases generated by all prior processing, including pre-processing that may have occurred prior to the FM-55 or SG-192. Energy increases contributed by the main and composite clippers are also accounted for, and it doesn’t matter how hard the clippers are driven or what pre-emphasis curve is in effect. Multiplex power is always effectively controlled.
The Multiplex Power Wizard is a standard feature in FM-55 audio processors and SG-192 stereo generators running software version 1.2.19 (or higher). Version 1.2.19 software can be downloaded free of charge from the Wheatstone web site (direct link FM-55 http://bit.ly/FM55SW) (direct link SG-192 http://bit.ly/SG192SW.