Boston Acoustics GT-42 manual

GT-42 4-Channel, High-Curr ent/High-Power Amplifier[...]

2 T able of Contents Parts List 3 Features and Specifications 3 Control Functions 4 Control functions (cont.) 5 Control functions (cont.) 6 Mechanical Functions 6 Control cover r emoval and reinstallation 6 Multi-position mounting feet 6 Mechanical functions (cont.) 7 Amplifier linking 7 Wi re connection 7 Fuses 7 General Installation Precautions[...]

Included Hardwar e (1) owner’ s manual (1) female quick-connect terminal for remote input (1) 2mm hex wrench (for speaker input) (1) 3mm hex wrench (for power input) (6) mounting screws 3 Parts List GT -42 Specifications 14.4VDC Power @ 4 Ohms 4x100W @ 2 Ohms 4x150W @ 4 Ohms (mono) 2x300W @ 2 Ohms (mono) 2x450W 12.6VDC Power @ 4 Ohms 4x75W @ 2 O[...]

4 Contr ol Functions FRONT RCA Inputs RCA cables marked “FRONT” from head unit or fr om other line level device should be connected here. Use both inputs (L & R) for ster eo. FRONT Remote Input Use the supplied FEMALE quick connector to connect the REMOTE trigger lead from the head unit to the amplifier . Amplifier turns “ON” when hea[...]

5 Contr ol Functions (cont.) “Q” Control “Q” Control is active when the highpass cr ossover is engaged and is centered on the selected crossover point. The range of operation is 0.7–1.2. REAR RCA Inputs RCA cables marked “REAR” from head unit or other line level device should be connected here. Use both inputs (L & R) for ster eo.[...]

6 Mechanical Functions Recessed RCA Inputs The input jacks are r ecessed into the body of the amplifier to provide clear- ance in tight mounting locations. Control Cover Removal and Reinstallation The cover panel is secured with two (2) captive coin-slotted scr ews. Coin-slotted screws allow a coin edge to be used as a scr ewdriver to remove the p[...]

7 Mechanical Functions (cont.) Amplifier Linking The design of the side panels enables multiple amplifiers to be used together without additional hardwar e. Wire Connection Amplifier accepts stripped wire dir ectly into the terminal blocks. Speaker outputs accept 8-gauge, and the DC power and ground accept 4-gauge. Tighten with supplied hex wren[...]

8 Before Y ou Install Before you install the unit, disconnect the negative (–) battery cable in the engine compartment of the vehi- cle. Doing so will prevent damage to both the electrical system of the vehicle and the amplifier during installation. Wire Routing Do not run the power wire near any low-level signals or audio cables such as the RCA[...]

9 13mm ( 1 / 2 ”) 548mm (21 5 / 8 ”) 225mm (8 7 / 8 ”) Choose the Mounting Location Plan your installation so that the amplifier is mounted where adequate ventilation is available. Never mount an amplifier in the engine compartment of a vehicle! W ARNING! Before driving the mounting scr ews thr ough any surface, be sure of what is behind th[...]

10 Passenger and T runk Compartment Mounting If the amplifier is mounted under a seat, be sure that the vents do not become blocked. Do not allow seat padding or other obstructive material to press down on the amplifier . All Boston GT amplifiers have top panel controls. If the amplifier is mounted under a seat, position the amplifier so the c[...]

Power/B+ and Power/GND Connection Strip approximately 5 / 8 " (16mm) of insulation. The positive (+) power wir e is installed into the amplifier terminal marked “B+.” The negative (–) wire is installed into the terminal marked “GND.” The ground wir e should be as short as possible and connected directly to the chassis of the vehicle[...]

12 Mono Subwoofer Operation If the amplifier is to be bridged and used with a subwoofer connected to the REAR channels, use the “SPEAKER OUTPUT” terminals marked for mono use. W ARNING! Subwoofer impedance must not fall below 2 ohms when in MONO mode. Installation—Fuses and Wiring (cont.) 1) Music The material chosen for head unit/amplifier[...]

13 Setup T uning—Full-Range Speakers (cont.) 4) Head Unit The head unit should have all controls such as bass, tr eble, balance, and fader set to the flat or centered position. The volume control should be at the minimum setting. If the head unit has any equalization or bass management features such as boost, they should be defeated at this time[...]

14 8) FRONT “Q” Control Once the FRONT highpass crossover point has been determined, use the FRONT “Q” control to incr ease the bass information centered ar ound the crossover point. Setting the front “Q” contr ol is done in conjunction with setting the levels on the input sensitivity and highpass crossover fr equency controls. Y ou may[...]

15 5) REAR Input Sensitivity Control Tu rn controls all the way counter clockwise (minimum position). In this position, the amplifier will be less sen- sitive to the input signal from the head unit. Slowly r otate this control clockwise until maximum undistorted playing level is heard fr om the subwoofers. Listen closely for faults such as bottomi[...]

16 System Examples System A—Full-Range Front with Full-Range Rear 6 . 5 L F 6 . 5 L F 6 . 5 L F 6 . 5 L F fuse to + battery terminal to ground fuse to + battery terminal to gr ound System B—Full-Range Front with Rear Fill 6 . 5 L F 6 . 5 L F 6 . 5 L F 6 . 5 L F fuse to + battery terminal to ground fuse to + battery terminal to ground[...]

17 System Examples (cont.) System C—Main Speakers with Single Subwoofer (2 Ω ) System D —Main Speakers with Parallel 4 Ω Subwoofers (2 Ω load) 6 . 5 L F 6 . 5 L F 10.5LF 2 Ω fuse to + battery terminal to ground fuse to + battery terminal to gr ound 6.5LF 6.5LF 6 . 5 L F 6 . 5 L F fuse to + battery terminal to ground fuse to + battery te[...]

18 Amplifier T r oubleshooting Guide Status LEDs on Amplifier not Lit — Head Unit (Sour ce) T urned “ON” V erify Remote turn-on wire fr om source to amplifier has pr oper voltage Power (B+) connections at amplifier , terminal blocks, and battery are secure Ground (GND) connections at amplifier and vehicle chassis ar e secure Battery B+ f[...]

19 Contact and W arranty Information 300 J ubilee Drive Pe a b o d y, MA 0 1 960 U.S.A. (978) 538-5000 Boston, Boston Acoustics, and the Boston logo are r egister ed trademarks of Boston Acoustics, Inc. © 2003 Boston Acoustics, Inc. All rights reserved. Specifications subject to change without notice. P/N 042-001630-1 www .bostonacoustics.com Lim[...]