- Automotive Subwoofers Owner’s Manual P1040 P1042 P1240 P1242 
- Choosing an Enclosure JBL Pro Power GTp Series Thank you for purchasing a new JBL GTp subwoofer. Subwoofer installation requires woodworking skills and some experience disassembling and reassembling automotive interiors. If you lack the tools or necessary skills, have your subwoofer installed by an authorized JBL dealer. Warning: Playing loud music in an automobile can permanently damage your hearing as well as hinder your ability to hear traffic. We recommend listening at low levels while driving. 
- Connecting Your Subwoofer to Your Amplifier JBL Pro Power GTp Series JBL GTp subwoofers are available in two different configurations: single 4-ohm voice coil and dual 4-ohm voice coils. Depending on the amplifier you are using, you may use either single-voice-coil or dual-voice-coil subwoofers in singles or multiples to maximize the power available from your amplifier. 
- Specifications JBL Pro Power GTp Series P1040 10" Automotive subwoofer P1042 10" Automotive subwoofer, dual voice coil P1240 12" Automotive subwoofer P1242 12" Automotive subwoofer, dual voice coil Power handling (peak) 1400 Watts 1400 Watts 1400 Watts 1400 Watts Power handling (RMS) 350 Watts 350 Watts 350 Watts 350 Watts Sensitivity (2.