For more than 50 years, midrange and high frequency horns have been the hands-down choice for movie theater sound engineers. From the softest whispers... To the highest impact sound... Hrn drivers have no equal when it comes to clarity and dynamic range. The BIC Formula Theater Series carries on the legacy of the first Formula Series introduced in 1973. They offer an output capability of up to 116dB (live rock band levels), while offering refinements that surpass all of its predecessors.