The E.M. Long LF-165 is an 18-inch bass driver utilized in professional audio applications where powerful and clear low-frequency sound is essential. The driver is known for its ability to produce deep, extended bass notes, stemming from the specific design principles of E.M. Long's patented method for low-frequency extension. It is often used in specialized "ELF" (Extended Low Frequency) speaker systems which rely on this technology. The driver features a robust build quality, including a large diaphragm and durable materials, making it suitable for demanding use in large sound systems, home theaters, or car audio installations. The design focuses on high excursion to achieve powerful bass reproduction without distortion at high sound pressure levels (SPLs).