HARMAN KARDON W12GTI
Owner's Manual

The Official Brand of Live Music
Thank you for choosing a JBL GTi Series subwoofer. GTi Series subwoofers are designed to provide maximum sound output in a variety of enclosure types while maintaining the superb sound quality associated with JBL. To ensure the best subwoofer performance, we strongly recommend that installation be entrusted to a qualified professional. Although these instructions explain how to install a GTi Series subwoofer in a general sense, they don�t show the specific installation procedures that may be required for your particular vehicle. If you feel you don�t have the necessary tools or experience, don�t attempt the installation yourself; rather, ask your authorized JBL dealer about professional-installation options. Warning: Playing loud music in an automobile can hinder your ability to hear traffic, as well as permanently damage your hearing. We recommend listening at low levels while driving. JBL accepts no liability for hearing loss, bodily injury or property damage resulting from use or misuse of this product. Your Car and Bass Reproduction Depending on the size of the vehicle�s interior listening space, reproduced frequencies below 80Hz may be boosted by nearly 12dB per octave as frequency decreases. This effect, commonly known as transfer function or cabin gain, plays an important role in defining the in-car frequency response of your subwoofer. It is displayed graphically, along with freespace response, on the enclosed data sheet for your GTi subwoofer. Power-Handling Limitations The power-handling capacity of any subwoofer is related to the excursion limit of its suspension and its ability to dissipate heat. A speaker reaches its excursion-limited power-handling capacity when its suspension is stretched to its limit. The excursion curve shown on the Enclosure Design Sheet (included with your woofer) displays cone excursion at the input power level required to drive the woofer to maximum linear excursion (Xmax). The input power shown may be used as instantaneous input only. Thermal power handling is determined by the amount of heat that may be dissipated by the driver�s voice coil. The powerhandling rating assigned to your GTi Series subwoofer is its thermal-power-handling rating. This rating assumes a clean (unclipped) signal. A clipped waveform has much higher average power, due to the longer duty cycle at the top and bottom of the waveform; it will heat the woofer�s voice coil faster than a clean signal and may damage the voice coil. A square wave has a 100% duty cycle and is extremely dangerous for any speaker. Audible distortion in the output of your woofer is an indication that your amplifier may be clipping, which could damage your speakers over time.

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