Boston Acoustics GT-20 GT-222 manual

GT-20 GT-22 2-Channel, High-Curr ent/High-Power Amplifiers[...]

2 T able of Contents Parts List 3 Features and Specifications 3 Control Functions 4 Control functions (cont.) 5 Mechanical Functions 6 Recessed RCA inputs 6 Control cover r emoval & reinstallation 6 Multi-position mounting feet 6 V ents (side & rear) 6 Mechanical functions (cont.) 7 Amplifier linking 7 Wi re connection 7 Fuses 7 General I[...]

Included Hardwar e: GT -20 & GT -22 (1) owner’ s manual (1) female quick-connect terminal (1) 2mm hex wrench (for speaker input) (1) 3mm hex wrench (for power input) (4) mounting screws 3 Parts List Te chnical Specifications GT -20 GT -22 14.4VDC Power @ 4 Ohms 2x55W 2x100W @ 2 Ohms 2x100W 2x175W @ 4 Ohms (mono) 1x200W 1x350W @ 2 Ohms (mono)[...]

4 Contr ol Functions RCA Inputs RCA cables from head unit or fr om other line level device should be connected here. Use both inputs (L & R) for ster eo; use “L” input for mono. 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 head u[...]

5 Contr ol Functions (cont.) Lowpass Crossover Contr ols To use 12dB/octave crossover , move switch to right-hand position. Lowpass crossover fr equency is adjustable from 50Hz to 350Hz by r otary control. (Moving switch to left-hand position will bypass crossover functions.) “Q” Control The “Q” Control is active when the highpass cr ossove[...]

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 & 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[...]

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 57mm (2.5") 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 that sur- face. Check for gas tank, brake li[...]

10 Passenger & 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[...]

Power/B+ & 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 vehic[...]

12 Mono Subwoofer Operation When the amplifier is configured for mono operation, 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 & Wiring (cont.) 1) Music The material chosen for head unit/amplifier system setup must be both clear in recor [...]

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 tim[...]

14 8) “Q” Control Once the highpass crossover point has been determined, use the “Q” contr ol to increase the bass information center ed around the cr ossover point. Setting the “Q” control is done in conjunction with setting the levels on the input sensitivity and highpass crossover fr equency controls. Y ou may find while setting the[...]

15 4) Input Sensitivity Control Tu rn contr ol all the way counterclockwise (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 subwoofer(s). Listen closely for faults such as bottoming f[...]

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

17 System Examples (cont.) System C—Single Subwoofer (2 Ω ) System D —Parallel 4 Ω Subwoofers (2 Ω load) fuse to + battery terminal to ground 10.5LF 2 Ω fuse to + battery terminal to ground 10.5LF 4 Ω 10.5LF 4 Ω[...]

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 042-001565-2 www .bostonacoustics.com Lim[...]