Here is the DB Drag rule on source material.
General Rules 1-1
-Competitors may use the program material of their choice while competing.
Additional Guidelines:
* The program material being played must originate from a source unit that is specifically designed for installation and operation in a 12-Volt auto sound environment. This includes cassette decks, CD players and changers, DVD players and changers, VCR's and VCP's, MP3 units, AM / FM / Satellite radio tuners, and any other playback device that is specifically designed for installation and operation in a 12-Volt auto sound environment.
* The program material may consist of music, test tones, or any other type of recorded audio signal.
* The program media may be from a commercial source (such as a CD you purchase) or a custom, homemade recording.
* Tone generators, frequency multipliers, harmonizers, etc. are prohibited.
Exceptions:
* Competitors must use the officially approved dB Drag Racing competition CD at all multi-point events. If an event takes place prior to the release of the official CD, then the previous year's CD may be used in the interim. (Please visit http://www.termpro.com/dbdrag/rules for more information regarding the current season's officially approved CD.)
* Competitors are limited to playing frequencies between 20 and 80 Hz at all multi-point events. If a competitor's highest SPL is achieved at a frequency below 20 Hz or above 80 Hz, then that competitor's score will be disallowed. If the violation occurs during the qualifying rounds, the competitor may be granted a retry at the sole discretion of the head judge. If the violation occurs during the elimination rounds, the competitor will be eliminated from the competition, regardless of the competitor's score.
