DB drag racing
Encyclopedia
dB drag racing is a competition rewarding the person who can produce the loudest sound inside a vehicle. The "dB" means decibel
s of sound pressure level (SPL). In these competitions, Sound Pressure Level (SPL) of 155 dB can be reached, and it is not unheard of to see more than 160 dB as well.
Competitive vehicles can range from a small vehicle with a single amplifier and subwoofer
up to a large van with dozens of amplifiers and subwoofers powered by dozens of car batteries and with upgraded electrical wiring and alternators.
There were 10,000 competitors in 2003 and 300 "races". U.S. National Championships were held in Tennessee
.
During a competition, the vehicle must be driven 20 feet. Nobody is allowed to sit in the vehicle during trials because injury would be certain. The vehicles are sealed tight to maximize containment of the sound energy for the decibel level meter. The competitor stands away from the vehicle with an on/off switch control while a computer voice announces the stages for the "races". The test tone consists of a very short resonating tone between 30 Hz and 70 Hz, called "the burp".
For comparison:
The perceived loudness doubles with every 10 dB increase. Direct comparisons, however, can only be made with the same measurement techniques, and the same weighting scale.
Decibel
The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...
s of sound pressure level (SPL). In these competitions, Sound Pressure Level (SPL) of 155 dB can be reached, and it is not unheard of to see more than 160 dB as well.
Competitive vehicles can range from a small vehicle with a single amplifier and subwoofer
Subwoofer
A subwoofer is a woofer, or a complete loudspeaker, which is dedicated to the reproduction of low-pitched audio frequencies known as the "bass". The typical frequency range for a subwoofer is about 20–200 Hz for consumer products, below 100 Hz for professional live sound, and below...
up to a large van with dozens of amplifiers and subwoofers powered by dozens of car batteries and with upgraded electrical wiring and alternators.
There were 10,000 competitors in 2003 and 300 "races". U.S. National Championships were held in Tennessee
Tennessee
Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...
.
During a competition, the vehicle must be driven 20 feet. Nobody is allowed to sit in the vehicle during trials because injury would be certain. The vehicles are sealed tight to maximize containment of the sound energy for the decibel level meter. The competitor stands away from the vehicle with an on/off switch control while a computer voice announces the stages for the "races". The test tone consists of a very short resonating tone between 30 Hz and 70 Hz, called "the burp".
For comparison:
- 163 dB—Windows break
- 150 dB—Jet engine at 30 m
- 140 dB—Threshold of pain
The perceived loudness doubles with every 10 dB increase. Direct comparisons, however, can only be made with the same measurement techniques, and the same weighting scale.
A-weighting
A Weighting curve is a graph of a set of factors, that are used to 'weight' measured values of a variable according to their importance in relation to some outcome. The most commonly known example is frequency weighting in sound level measurement where a specific set of weighting curves known as A,...
External links
- dB Drag Racing Website
- "This American LifeThis American LifeThis American Life is a weekly hour-long radio program produced by WBEZ and hosted by Ira Glass. It is distributed by Public Radio International on PRI affiliate stations and is also available as a free weekly podcast. Primarily a journalistic non-fiction program, it has also featured essays,...
" radio broadcast ("Auto Show"). - Extreme SPL Racing
- CNN report
- World Record 180.5 dB from a Single Subwoofer