The Qi65CB speaker has been designed to offer exceptional value in terms of performance and cost its efficiency is particularly high in fact it requires less than half the amplifier power of the standard Qi65C to produce the same volume of sound. It is also incredibly shallow making it Q Installs slimmest speaker with a maximum rear depth of just 73 mm. The full range driver has been carefully designed to give good bass extension a detailed mid-range for voice reproduction and an extended high frequency range without the need for a conventional crossover and tweeter arrangement.