• 12" woofer

• Progressive wave diaphragm, double coated front and back side

• Undercut T pole with thick copper ring below and thick aluminum ring above

• Patented Intercooler system for low temperature and long life

The PHL 4021 is designed for use as a subwoofer in a recording studio or theatre. It has good bass extension with high. The cloth surround allows for smooth extended high frequency and long life. It features a very fast and tight punchy bass like an 8". Ruler flat to 500 Hz. crossover. For best performance use a 71 liter vented enclosure for -3dB at 33 Hz. The port tune is 35 Hz., use two tubes each 4" diameter by 17' long. 500 watt amplifier = 116 dB.