JBL ES150PCH 300-Watt Powered 10" Subwoofer - Cherry (Discontinued by Manufacturer) A JBL computer-optimized bass-reflex port provides deeper bass and less turbulence. Use of premium components gives you less distortion. These speakers are designed to look good anywhere with a style that equals their substance. The JBL ES Series uses cellulose-fiber cones reinforced with a ploymer coating for uniform pistonic motion: this eliminates internal resonances, without increasing cone mass. This means tighter, more precise imaging over a wider listening area.