Jbl Shock Wave 4T. 4” Aluminum Bullet Horn Super Tweeter with Titanium Diaphragm 35W RMS @ 4Ω Bullet Type Phase Plug Horn Design The bullet type phase plug horn is capable of providing remarkably efficient, high output for a given input power. The tweeter helps optimize sound dispersion by controlling directivity, allowing greater SPL whether on or off axis. Compression Driver Technology The tweeter uses compression driver technology for increased maximum SPL, sensitivity and bandwidth, as well as reduced harmonic distortion. High Quality Die Cast Aluminum Housing The elegant aluminum die cast housing allows for a classy aesthetic integration in any car. Titanium Diaphragm The extremely rigid titanium diaphragm is light weight and low density, allowing for a flatter response, broad frequency range and pinpoint accuracy. Versatile Fitting Options The Shock Wave 4T is conveniently designed with a 37mm (1.5-inch) mounting depth and 72mm (2.8-inch) cutout diameter, allowing it to be installed in either car door or A pillar. Supplied Capacitor Two 2.2uF/100 volt capacitors are included to help eliminate potentially harmful low end frequencies.