It may not seem like school is the best place to crank up the bass for glass-cracking extreme energy, but subwoofers just might make better teaching and learning tools than they do music makers. Faced with the fact that electricity is invisible, electrical technology students encounter significant challenges in the classroom when abstract concepts and principles are introduced to illustrate the behavior of electricity. An electro-dynamic machine that can deliver 160 decibels of raw sound power, however, quickly captures a student's attention, and can go on to serve as a platform from which instructors can launch many lessons in electricity. The scope of instructional activities involving subwoofers is scalable and can be varied widely to bring students in contact with seemingly mysterious electrical phenomena. Depth of instruction and learner activities can be controlled to meet teacher goals and objectives by breaking the subwoofer up into its teachable parts: electrical, mechanical, and acoustical. (Contains 8 figures.)