To determine the real power of an amplifier, there is a special formula, knowing which you will not be mistaken when choosing a product. In general, this value is easy to calculate by remembering Ohm's law from the school curriculum.
Instructions
Step 1
When choosing a car subwoofer, use a special formula to calculate its power. Often times, manufacturers can provide a generic value for multi-channel devices, which is confusing for inexperienced buyers.
Step 2
Find out the efficiency of the amplifier. It directly depends on the class of your device. Class A amplifiers have a positive effect on the sound quality of music, but have low efficiency - about 20-30%. This is a rather rare indicator, which is mainly used in very expensive device models, since the sound quality is almost perfect. Amplifiers of class AB give an efficiency of up to 50%, they are used in most audio systems for cars, which is typical, with such a high efficiency, they give very good sound quality. Class D amplifiers so far only work with subwoofer systems, they use digital signal processing and are up to 80 percent efficient. This type of amplifier is extremely rare, especially when compared with class AB devices.
Step 3
Calculate the output power of your amplifier using the efficiency data. Multiply the voltage of the vehicle's electrical system with the engine running by the amperage. Multiply this value by the efficiency, and you get the power output of the amplifier, which is usually indicated on the price tags. Also double-check this value when purchasing.
Step 4
According to how many channels your amplifier has, divide the resulting value by this number, since this is the sum of all channels at once. The general formula for calculating the amplifier power per channel is as follows: P = (U * I * E) / N.
