GRAND TOURING® SERIES
Automotive Subwoofers
GT800, GT800d, GT1000, GT1000d, GT1200, GT1200d, GT1500, GT1500d Owner’s Manual
G E N U I N E J B L
Thank you for choosing a JBL GT Series subwoofer. GT Series subwoofers are designed to suit a broad range of mobile audio applications and can be used in a wide variety of enclosure types to produce extended, powerful bass in a limited amount of vehicle space. To ensure maximum subwoofer performance, we strongly recommend that installation be left to a qualified professional. Although these instructions explain how to install a GT Series subwoofer in a general sense, they do not show box construction details and exact
installation methods for your particular vehicle. If you do not feel you have experience, do not attempt the installation yourself, but instead ask your authorized JBL dealer about professional installation options.
Remember to keep your sales receipt with this manual in a safe place so both are available for future reference.
Your Car and Bass
Reproduction
Depending on the size of the vehicle’s interior listening space, reproduced bass frequencies below 80Hz are actually boosted by nearly 12dB per octave as frequency decreases. NOTE: This effect, known as the vehicle’s transfer function, plays an important part in shaping the overall in-car response and is displayed graphically along with freespace response on the enclosed data sheet for your GT Subwoofer.
Enclosure Calculations
and Building Boxes
Use the recommended box designs on the enclosed data sheet or look for them on our Web site at www.jbl.com. Choose cabinet dimensions to fit your vehicle, but do not change the enclosure’s volume. Doing so will change the tuning frequency of the enclosure and may adversely affect final performance. If you cannot perform the necessary calculations yourself, please contact your authorized JBL dealer for help and information about JBL Speakershop™, a dedicated enclosure-design software program for experienced car-audio enthusiasts.
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