The SB Acoustics SB Acoustics SB29RDAC-C000-4 is a fabric Ring-Radiator tweeter features an extended high frequency response. This results in a low distortion sound representation within the range of the human hearing. The chambers within this tweeter unit are designed for improved dynamics. The driver also features a low Fs point of 600 Hz to allow for a low crossover point. A crossover point of at least 2600Hz is recommend with a second order 12dB/oct slope.