Pioneer TS-A1688S 80W RMS 4-Way Speaker with Adapter and 350W maximum music power. The new, rigid carbon and mica-reinforced IMPP cone and Elastic Polymer Surround provide quicker response and higher sensitivity. Produces deep and rich bass sound. Pioneer’s OPEN and SMOOTH sound concept provides a seamless and smooth transition between the midrange and tweeter drivers and delivers uniform off-axis frequency response optimized for automotive applications where one or more speakers are often aimed away from the listeners’ ears. Based on recent research data, the design of the a-series adapter has been changed to offer only a wider range of installation options, but also higher damping and improved sound. Diameter: 6.5-Inch.