Depending on the amplifiers you are using, you may want to use either one or several subwoofers in the same enclosure to maximize the power available from your amplifiers. To achieve the maximum amplifier output possible, you should design a speaker system that provides the lowest impedance that your amplifier is rated to drive safely. When designing a subwoofer system, consider the following rules: 1. Don't mix different subwoofer or enclosure types in the same system. We recommend that you avoid connecting separate woofers in series. The amplifier-damping factor (the amplifier's ability to control the motion of the woofer) is expressed as a ratio of terminal impedance (the sum of speaker impedance, wire resistance and the D. resistance of any crossover coil connected to the woofer) to amplifier-output impedance. Therefore, connecting separate woofers in series reduces the damping factor of the amplifier to a value less than 1. This will result in poor transient response. Most amplifiers deliver exactly the same amount of power bridged into a 4-ohm load as they do running a 2-ohm stereo load. To design a subwoofer system that maximizes available amplifier power, keep the following rules in mind: 1. The total system impedance of woofers in parallel can be calculated using the formula: 1 Impedance = 1 1 1 + w + w. w1 2 3 where w is the nominal impedance of the woofer. The total system impedance of woofers in series can be calculated using the formula: Impedance = w1 + w2 + w3. The diagrams at right show parallel and series speaker connections. Figure 1. Parallel connection RED STRIPE POS ( + ) BLACK STRIPE NEG ( ­ ) POS ( + ) NEG ( ­ ) Figure 2. Series connection RED STRIPE POS ( + ) BLACK STRIPE NEG ( ­ ) POS ( + ) NEG ( ­ ) 2 Specifications JBL GT4 Series GT4-10 10" Automotive subwoofer Power handling (RMS) Power handling (Peak) Sensitivity (2...