Ever wandered about fairness in stereo competition?.
There are three different classes in the normal N.S.P.L. competition. These classes are the beginner class, the amatuer class, and the pro class, N.S.P.L. stands for National Sound Pressure League. The object in this competition is to acheicve as much bass pressure in an automobile as possible. There are certain specifications and reules that each competitor must follow within each class. There also many sub-classes in each of the three main classes, genereally pertaining to the power of the ampilfier(s) in a competitors vehicle. There have been these sub classes made to ensure that the competiton runs fair ( for example this will ensure that a setup powered by 100 watts dosent compete against a system that is powered by 2000 watts).
The Beginner SPL is for first time competitors who do not work in the 12 volt industry of electronics as an installer, or salesperson. A beginner vehicle must retain the rear seat with the system installed behind it. There cannot be a wall in a Beginner vehicle and the speaker box must be 12 inches or more from the roof. A Beginner Car vehicle may be a hatchback car (Ex: Honda CRX, Ford Probe). A beginner may also be a Truck/SUV vehicle (Ex: Chevy Blazer, Ford Ranger, Ford Explorer). If in the vehicle, hearing protection (ear plugs, headphones, etc.) must be worn.
The amatuer class is a little more strict in the rules by which a competitor is to compete. Upon entering the judging area, the power class/speaker class verification must take place before SPL testing. All amplifiers must be visible. All woofers must be shown to the judge if they have a grill cover before judging. The vehicle must be in park with the emergency brake applied. All windows in the vehicle must be rolled up. The doors must be closed. The engine may be running or cut off. (If running, there will be no revving. Engine must be no more than 2000 rpm.