FOX40 CMG Sonik Blast Whistle Properties: Referee and coach whistle. The latest model from FOX 40 Sonik Blast CMG official. The latest technology used in these whistles makes them the most effective in their class. This model emits a sound power of +120 dB. The whistle has two chambers and four sound resistors, making it much louder than its predecessors, the Fox Classic. The whistle is packed in the original blister!