The Classic stones are the smallest rock formations that we make. These models are available with a choice of three loudspeaker systems rated below as good, better and best selection based on sound quality and performance. (Standard) 125 Watt / 6-1/2” Two-Way 8 ohms better for small & medium sized areas including pools, spas and tennis courts. Sensitivity 89 db spl 1 watt / 1 meter Freq. Response 55hz - 20 khz +/- 3db.