This is IASCA ’s SPL competition format. IdBL Divisions (Amateur, Stock, Stock Advanced, Advanced and Ultimate) are based on the experience and industry position of the competitor and the level of modification to the vehicle. IdBL Classes are based on the cumulative total of all subwoofer cone surfaces in square inches (see cone area calculation chart).
Sound Pressure Level (SPL) measurements in deciBels (dB) are registered using the Official IASCA SPL meter . Determining the winner is simple; the highest score in each class wins! Any metering system may be used at SPE or DPE events, however at TKE’s and WRE events, the Official IASCA SPL meter must be used.
Typically, most show promoters will offer two scoring attempts, giving each competitor the opportunity to increase their previous score. The highest score of the two attempts will prevail.