All of the auto sound equipment used in the competitor's sound system must satisfy the following guidelines:
All auto sound equipment must be designed for installation and operation in an auto sound environment.
All auto sound amplifiers must be linear in nature.
The amplifiers used in the sound system should be designed for audio reproduction. For clarification purposes, the amplifier's output waveform should be a close facsimile to that of the input signal. In addition, the amplifier's output magnitude should be proportional to that of the input signal. All of these guidelines apply to frequencies between 20 and 80 Hz. The determination as to whether an amplifier is acceptable for use in dB Drag Racing competition shall be at the sole discretion of the dBDRA.
The program material must be reproduced using conventional loudspeakers (subwoofers). The determination as to whether a loudspeaker is acceptable for use in dB Drag Racing competition shall be at the sole discretion of the dBDRA.
The dBDRA defines a conventional loudspeaker as a sound reproducing electro-mechanical transducer that incorporates a cone, surround, basket, and voice-coil.
The loudspeaker must be powered directly by the audio amplifier(s).
Loudspeakers incorporating servo mechanisms, actuators, or any other form of mechanically powered motor are specifically prohibited.
Compressed air, explosive devices, etc. are expressly forbidden.
Competition vehicles and/or auto sound installations may NOT be altered during competition at the dBDRA Championship or at ANY multi-point event without obtaining approval from the head judge first.
The period of time from which alterations are prohibited begins with the start of the event (registration) and ends with the awards ceremony at the conclusion of the event.
If an alteration request is granted, the contestant will still be responsible for competing during his or her designated time.
Auto sound equipment may be replaced or exchanged at the contestant's discretion provided no other applicable rules are violated.
You may adjust the tuning frequency of your enclosure by adjusting the enclosure's vent.