4-Channel Amplifier Owners Manual GT-475 GT-4100
Table Of Contents Introduction Thank you for choosing Boston Acoustics® and congratulations on your purchase of the Boston GT® Amplifier. If you own other Boston products, the outstanding audio performance and ease-of-use of the GT Amplifier should come as no surprise. If you’re new to Boston, welcome – you’ve made a great choice.
Parts And Specifications Parts List Included Hardware: GT-475 GT-4100 Installation Manual Female Quick-Connect Terminal 1 1 1 1 1 1 4 1 1 6 (for remote turn-on input) 2mm Hex Wrench 3mm Hex Wrench Mounting Screws Specifications Technical Specifications: GT-475 GT-4100 Rated Power (CEA-2006-A): @ 4-Ohm (Stereo): @ 2-Ohm (Stereo) @ 2-Ohm (Mono) 75 Watts x 4 120 Watts x 4 250 Watts x 2 100 Watts x 4 150 Watts x 4 450 Watts x 2 Mixed Operation (CEA-2006-A): @ 4-Ohm (Stereo) & 2-ohm (Mono): 75
Connections Connections GT-4100 1 2 3 2 4 5 6 GT-475 1 u v w x y z { | 2 3 2 4 5 6 7 8 Front RCA Input Remote Turn-On (female spade connector supplied) Rear RCA Input Remote Gain Port (refer to GT-RSL manual for installation instruction) Front Left/Right/Mono Speaker Outputs (12-gauge accepted) Rear Left/Right/Mono Speaker Outputs (12-gauge accepted) 12v Power Input (4-gauge accepted) Ground Wire Input (4-gauge accepted) Top Panel Removal / Installation The cover panel is secured with t
Controls Controls GT-4100 1 2 3 4 6 5 7 8 9 10 11 12 GT-475 1 u v w x y z { | } ~ 2 3 4 5 6 7 8 9 10 11 12 Signal Routing Switch (Sends Front RCA Signal to Rear Channels) Front Channel Input Sensitivity (250mv to 8.0v - continuously variable) Front Channel Highpass Frequency Adjustment (20Hz to 350Hz - variable) Front Channel Highpass Crossover OFF/ON Switch Front Channel Highpass Crossover Q-Tune™ Adj. (0.707 to 1.
Installation - General Installation - General WARNING! Before driving the amplifier mounting screws through any surface, be sure of what is behind that surface. Check for the gas tank, brake lines, and any vehicle wiring harness. Never run wires outside or under the vehicle or where they could become broken or interfere with the safe operation of the vehicle. Before You Install Before you install the unit, disconnect the negative (–) battery cable in the engine compartment of the vehicle.
Amplifier Fuses Although the amplifier has an internal fuse, additional fuse protection should be installed as close as possible to the battery on the positive (+) power wire going to the amplifier. An inline fuse should be installed at no more than 18" (46cm) on the positive (+) power wire. The rating of the inline fuse should equal the value of the internal fuse of the amplifier if only the single amplifier is connected to this wire.
Tuning - Front and Rear Speakers Tuning The Amplifier - Front and Rear Speakers 1) Music The material chosen for system tuning must be both clear in recording quality and dynamic in amplitude. Many audiophile “test” discs have musical tracks with both of these characteristics and should be used. 2) Front Signal Routing Switch If using two sets of RCAs (independent front and rear RCAs), set the switch to DEDICATED FRONT AND REAR INPUTS .
6) Input Sensitivity Control Starting with the front channels, slowly rotate the control clockwise (refer to the diagram on page 5) until maximum undistorted playing level is heard from the speakers. Listen closely for bottoming from the speakers. If detected, rotate the input sensitivity control counterclockwise until it is eliminated. Repeat for the rear channels.
Tuning - Subwoofers Tuning The Amplifier - Front Speakers and Subwoofer (s) 1) Front Signal Routing Switch If using two sets of RCAs (independent front and rear RCAs), set the switch to DEDICATED FRONT AND REAR INPUTS . If you are using one set of RCAs for both front and rear channels, set the switch to SEND FRONT RCA SIGNAL TO REAR. (refer to the diagram on page 5). 2) Head Unit The head unit should have all controls such as bass, treble, balance, and fader set to the flat or centered position.
Highpass Crossover Control (Front Channel Only) Cont. Slowly rotate the input sensitivity control clockwise until maximum undistorted playing level is heard from the speakers. Listen closely for bottoming from the speakers. If detected, rotate the input sensitivity control counterclockwise until it is eliminated. Slowly rotate the highpass crossover control counterclockwise while listening for bottoming. You are lowering the crossover point, which means that more bass signal is being sent to the speakers.
Amplifier Troubleshooting Guide Status LEDs on Amplifier not Lit—Head Unit (Source) Turned “ON” Verify Remote turn-on wire from source to amplifier has proper voltage Power (B+) connections at amplifier, terminal blocks, and battery are secure Ground (GND) connections at amplifier and vehicle chassis are secure Battery B+ fuse and amplifier fuse are OK B+ at battery and B+ at amplifier have proper voltage Status LEDs Lit, no Output from Speakers—Speakers in Normal Operating Condition Verify High-level cable
