Beachfront SPL (Beach SPL) - this category is designed to identify the loudest cars in the front and rear, the category has 5 classes with different distinctions from the more casual to true volume maniacs.
The measurement lasts 30 seconds, during which time the participant must achieve their best performance. During this time, the sensor captures the entire frequency spectrum from 100 to 18,000 Hz and from 60 to 16,000 Hz for BDW classes. The measurement takes place on a randomly selected track at the venue on the day of the competition. The format publishes the tracks where the measurements will be taken before the start of the season.
For classes Gate 1-6, Wicket 6-10 and Wicket 10+ - the sensor can be located at a height of 60 to 100 cm from the ground (at the participant's choice, in 1 cm increments) and 1 meter from the measured door, as well as 40 cm from the car, the direction of the microphone is in the center of the measured door.
- The participant must inform the judge at what height they want the sensor to be set, for example, 74 cm. If the participant does not indicate the desired height, the sensor is set at the last mark placed.
For the Back Door Wall class, the sensor is also located in the center of the measured surface at a distance of 2 meters and from 1 meter to 1.5 meters from the ground, with a step of 1 cm.
The participant must inform the judge at what height they want the sensor to be set, for example, 1 meter 22 cm. If the participant does not indicate the desired height, the sensor is set at the 1 meter mark.
Measurements are based on standard 6.5-inch speakers. So, if the speaker size is 8x6.5, then it's 5x8 inches. Each driver counts as one 6.5-inch speaker. The tweeter area is not included.
For example, if 6 6.5-inch speakers equal 1283.88 sq. cm, then 4 8-inch speakers fall into this class, since their total area is 1296.52 sq. cm.
The measurement is based on the useful area of the speaker!
IMPORTANT: The sensor is positioned 40 cm from the side of the vehicle in front of the door being measured, with the 1-meter measurement taken from the outermost point of the trim. For BDW classes, the distance to the sensor is also measured from the outermost point of the vehicle or trim, depending on the class.