Features
Controls
Input and Output Notes

Features

Dual Mode Capable: The Boston Acoustics GT-40 allows for 1-ohm stereo or 2-ohm mono operation, increasing the amplifier's application flexibility. The GT-40 amplifier excels in combining full-range and subwoofer applications.

Tri-Way Capable: The amplifier's front and rear channels can both be bridged but only the rear channels contain a low-pass crossover allowing you to connect a subwoofer. The amplifier can be set-up in a Tri-Way configuration to provide power to your full-range speakers and subwoofers. In this application the front channels will power a set of full-range speakers (with or without using the high-pass crossover) and the rear channels are bridged to power one or two subwoofers with the low-pass crossover engaged. In this mode the amplifier is rated at 55 watts RMS x 2-channel at 4 ohm and 240 watts RMS x 1-channel at 2 ohm.

Low-Profile Design: The compact and low-profile design allows for installations in tight locations where other amplifiers will not fit.

DPS (Dynamic Power System): This technology ensures high efficiency at the output stages, increased power with lower impedance and maximum dynamics and instantaneous response.

Forced Air Cooling: This advanced cooling system allows you to mount the amplifier in various positions. You can even mount the amplifier upside down. This design also offers reduced weight and increased cooling efficiency over traditional heat sinks. The amplifier is equipped with side and rear vents.

Mosfet Output Stages: The amplifier uses highly efficient Mosfet output stages for quick recovery under heavy transient conditions.

Q-Tune: This technology combines sophisticated crossover adjustments with Q-Control settings to seamlessly transition rear bass to the front sound stage.

Multi-Position Mounting Feet: The mounting feet are designed to slide in both directions to clear installation obstructions on the mounting surface to make for an easier installation.

Amplifier Linking: The design of the side panels enables multiple amplifiers to be used together without additional hardware. This allows for a very clean and professional look for multi-amp systems.

Status LED Indicators: The LED indicators on the amplifier lets you know when you amp is on or when it is malfunctioning.

• Green Indicates normal operating conditions.
• The Green and Red Indicator light will come on when the amplifier is first turned on. The red will turn off after a few seconds.
• When both Red and Green remain on, the amplifier is in thermal shutdown mode.
• When only the Red LED is on, it indicates a fault condition.

Controls

Removable Control Cover: The GT-40 amplifier features a removable aluminum control cover that conceals all controls of the amp. The cover provides a cleaner look, and it prevents accidental adjustment of the settings once they are set.

Front Input Switch: The Front Input Switch allows you to connect two pair of RCA inputs giving you fading capabilities of front and rear channels or allows you to connect only one pair of RCA inputs incase your head-unit only features one set of preamp outputs. In this mode, only the Left and Right Front RCA inputs are connected but the connection still sends the audio signal to both the Front and Rear channels of the amplifier.

Rear Input Switch: You may select stereo or mono operation, depending on your application for the rear channels.

Input Sensitivity Control (Gain Control): The amplifier features independent gain control for the front and rear channels. This control is used to match the incoming signal from your CD receiver to the amplifier to give you the best overall sound quality. Turn control clockwise to increase the amplifier sensitivity and counterclockwise to decrease the amplifier sensitivity.

Front and Rear High-pass Crossover Controls: The high-pass crossover controls allow you to filter out frequencies between 20Hz to 350Hz to your front speakers and 50Hz to 350Hz to your rear speakers that you want to keep certain bass frequencies from to prevent distortion. You can turn the High-pass filter off for full range use.

Rear Low-pass Crossover Controls: The low-pass crossover controls allow you to permit only frequencies between 50Hz to 350Hz to your subwoofers when connected to the rear channels to prevent any distorted high frequencies from playing through your subs. The front channels do not have a low-pass crossover setting.

Q Control: The "Q" Control is active when the high-pass crossover is engaged and is centered on the selected crossover point. The range of operation is 0.7 to 1.2. Use this control to increase the bass information centered around the high-pass crossover point.

Subwoofer Level: The amplifier can be used with the optional GT-RSL wired subwoofer level controller (sold separately). The wire controller uses voltage control amplification to adjust subwoofer level, eliminating noise and phase error issues. The Subwoofer Level switched should be turned set to "Off" when not in use and set to "On" when in use. The connection for the GT-RSL controller is found on the front of the amplifier behind a removable plastic panel held in place by two small phillips screws.

Input and Output Notes

Connections: All input and output connections are located on one side of the amplifier to make installation and wire management easier.

RCA Inputs: The amp includes two sets of recessed RCA inputs to connect from the RCA outputs of your head unit or processor. The recessed design provides clearance in tight mounting locations.

Dual Remote Inputs: The supplied female quick-connector can be used to connect the remote turn-on lead (not supplied) from the head unit to the amplifier. This lead turns the amplifier "On" when head unit is turned "On". The amplifier has separate remote turn-on inputs for the front and rear channels but they are wired in parallel inside the amplifier so only one needs to be connected.

Power Connections: The amplifier accepts stripped bare wire into the power and ground terminals. Both terminals can accept up to a 4-gauge wire. The set screws can be tightened with the supplied 3mm hex wrench.

Speaker Connections: The amplifier accepts stripped bare wire into the speaker terminal blocks. The speaker outputs accept up to an 8-gauge wire. The set screws can be tightened with the supplied 2mm hex wrench.

Subwoofer Level: Proprietary 9-pin connection for optional GT-RSL wired remote controller found behind plastic panel held in place by two phillips screws.

Fuses: The amplifier accepts standard AT-style automotive blade fuses. It comes equipped with two 25amp blade fuses.