waves at various DC motor speeds—not as a response to audio signal—it could not play music. The driver was mounted in a stepvan owned by Tim Maynor but was too powerful for the amount of applied reinforcement and damaged the vehicle. MTX's Loyd Ivey helped underwrite the project and the driver was then called the MTX "Thunder 1000000" (one million). Still unfinished, the vehicle was entered in an SPL competition in 1997 at which a complaint was lodged against the computer control of the DC motor. Instead of using the controller, two leads were touched together in the hope that the motor speed was set correctly. The drive shaft broke after one positive stroke which created an interior pressure wave of 162 dB. The Concept Design 60-inch was not shown in public after 1998. MTX Jackhammer The heaviest production subwoofer intended for use in automobiles is the MTX Jackhammer by MTX Audio, which features a diameter cone. The Jackhammer has been known to take upwards of 6000 watts sent to a dual voice coil moving within a strontium ferrite magnet. The Jackhammer weighs in at and has an aluminum heat sink. The Jackhammer has been featured on the reality TV show Pimp My Ride. See also Bass management Mid-range speaker Power Alley Super tweeter Rotary woofer Thiele/Small Tweeter Woofer References Loudspeakers In-car entertainment Audio engineering Film and video technology Bass (sound) Loudspeaker technology Audio hobbies