User manual JBL GT122

[. . . ] Although these instructions explain how to install a GT Series subwoofer in a general sense, they do not show box construction details and exact 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. [. . . ] 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 SpeakershopTM, a dedicated enclosure-design software program for experienced car-audio enthusiasts. 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. 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. 01 Specifications GT Speakers Specifications: Configuration Recommended power amplifier range Sensitivity (@ 2. 83 volt/1 meter) Frequency response Mounting Depth Top mount Bottom mount Dimensions Cut-out diameter GT800 8" woofer 18W ­ 200W 93dB 35Hz ­ 5kHz 3-13/16" (97mm) 4-5/16" (110mm) 7-1/8" (181mm) GT800d 8" woofer, dual voice coil 18W ­ 200W 93dB 35Hz ­ 5kHz 3-13/16" (97mm) 4-5/16" (110mm) 7-1/8" (181mm) GT1000 10" woofer 18W ­ 260W 94dB 30Hz ­ 3. 5kHz 5-1/8" (131mm) 5-5/8" (143mm) 9-1/4" (235mm) GT1000d 10" woofer, dual voice coil 18W ­ 260W 94dB 30Hz ­ 3. 5kHz 5-1/8" (131mm) 5-5/8" (143mm) 9-1/4" (235mm) Specifications: Configuration Recommended power amplifier range Sensitivity (@ 2. 83 volt/1 meter) Frequency response Mounting Depth Top mount 3-3/8" (86mm) Bottom mount Dimensions Cut-out diameter GT1200 12" woofer 18W ­ 280W 95dB 25Hz ­ 3kHz 5-3/4" (147mm) 6-1/4" (159mm) 11-1/8" (283mm) GT1200d 12" woofer, dual voice coil 18W ­ 280W 95dB 25Hz ­ 3kHz 5-3/4" (147mm) 6-1/4" (159mm) 11-1/8" (283mm) GT1500 15" woofer 18W ­ 300W 97dB 20Hz ­ 2kHz 6-11/16" (170mm) 7-3/16" (183mm) 13-15/16" (355mm) GT1500d 15" woofer, dual voice coil 18W ­ 300W 97dB 20Hz ­ 2kHz 6-11/16" (170mm) 7-3/16" (183mm) 13-15/16" (355mm) 01 Sealed enclosures exert the most control over the motion of a subwoofer because the air acts like a spring against the motion of the woofer cone. Larger boxes allow for more excursion (cone movement), thus more lowfrequency output for the amount of power used. When placed in a sealed box larger than the compliance (Vas) of the subwoofer, it will perform as if it were in an infinite baffle installation. Vented and bandpass enclosures have the lowest amount of excursion for the amount of sound output. Since speaker-cone excursion is different for each type of enclosure, power handling is different for each enclosure. · Voice-coil overheating and burning due to over-excursion is often caused by overdriving an amplifier into "clipping. " A severely clipped signal, or squarewave, contains nearly twice the power of a clean sine wave at the same level. Bass that sounds broken up and distorted at higher volumes usually indicates that the amplifier is being asked to deliver power beyond its ability. · Infinite baffle or "free air" mounting applications allow for greater cone excursion than subwoofers mounted in an enclosure. In order to compensate, recognize that the power-rating value of the subwoofer will likely be half its rated power in this application. · Study the excursion curves on the enclosed GT Series data sheet and note the differences for different enclosure applications. The type and size of box used will produce different excursion demands on the enclosed subwoofer and, consequently, different levels of power handling. As long as recommended parameters are used, the subwoofer will perform properly in its enclosed environment. However, any design deviation may result in less than optimum performance, and may also subject the subwoofer to overexcursion that can eventually damage the speaker. [. . . ] The type and size of box used will produce different excursion demands on the enclosed subwoofer and, consequently, different levels of power handling. As long as recommended parameters are used, the subwoofer will perform properly in its enclosed environment. However, any design deviation may result in less than optimum performance, and may also subject the subwoofer to overexcursion that can eventually damage the speaker. For additional help with this issue, please contact your authorized JBL dealer. Declaration of Conformity We, JBL Europe A/S Kongevejen 194B DK-3460 Birkerød DENMARK declare in own responsibility, that the products described in this owner's manual are in compliance with technical standards: EN 50 081-1/1992 EN 50 082-1/3. 1995 Steen Michaelsen JBL Europe A/S Birkerød. [. . . ]