Alpine R2-A75M & R2-A60F Power Amplifiers

User Manual

Introduction

This document provides detailed instructions for the Alpine R2-A75M Mono Power Amplifier and R2-A60F 4-Channel Power Amplifier. It covers safety precautions, installation, connections, switch settings, system diagrams, and specifications.

Important Safety Information

WARNING: Read this manual carefully before use. Failure to follow instructions may result in serious injury or death.

Do not operate functions that distract from driving. Stop the vehicle safely before adjusting.
Maintain a safe listening volume to hear external sounds like emergency sirens. High volumes can also cause hearing damage.
Do not disassemble or alter the unit, as this may cause accidents, fire, or electric shock.
Use only for 12V mobile applications.
Use the correct fuse ampere rating when replacing fuses.
Do not block vents or radiator panels to prevent overheating and fire.
Ensure correct connections to prevent fire or product damage.
Use only with 12-volt negative ground systems.
Disconnect the negative battery terminal before wiring to prevent electric shock or injury.
Arrange cables to prevent entanglement with moving parts or sharp edges.
Do not splice into electrical cables; this can exceed wire capacity and cause fire or shock.
Avoid drilling into pipes, fuel lines, tanks, or wiring to prevent fire.
Never use bolts or nuts from brake/steering systems for ground connections, as this can disable vehicle control.
Keep small objects like batteries out of reach of children.
Halt use immediately if a problem occurs to prevent injury or damage.
Have wiring and installation performed by experts.
Use only specified accessory parts and install them securely.
Route wiring away from moving parts and sharp edges. Use grommets for holes in metal.
Avoid installing in locations with high moisture or dust.

Service Care

This amplifier has been type tested and complies with FCC Rules Part 15 for Class B computing devices. Record your unit's serial number for permanent records. For warranty questions, consult your store of purchase or dealer.

Accessories

Self-Tapping Screw
Hexagon Wrench (1 Set)

Installation

Due to high power output, the amplifier generates considerable heat. Mount it in a location allowing free air circulation, such as a trunk. For alternative locations, contact an authorized Alpine dealer.

Installation steps:

Use the amplifier as a template to mark four screw locations.
Ensure no objects behind the surface will be damaged during drilling.
Drill the screw holes.
Position the amplifier over the holes and secure with four self-tapping screws.

Removing the Top Cover: To access the top inner panel, remove the top cover using the included Hexagon wrench.

Connections

Ensure all audio components are powered off before making connections.

General Connection Points:

Speaker Output Terminals: Connect speaker leads using the hexagon hole screw. Ensure correct polarity (+ to +, - to -).
Subwoofer Input/Output (R2-A75M only): Input is stereo, output is monaural. Reversing polarity may improve bass performance.
Bridged Connections (R2-A60F only): Connect left positive to speaker positive, right negative to speaker negative. Do not use speaker (-) terminals as a common lead.
Remote Bass Control (optional): Connect the RUX-KNOB.2 for remote level adjustment.
Pre-Out Jacks (R2-A75M only): Provides a line-level, full-range output for driving a second amplifier.
RCA Input Jacks: Connect to head unit line-out leads using RCA extension or Speaker-RCA conversion cables. Match channels (Left to Left, Right to Right).
Fuse: R2-A75M uses 40A x 2; R2-A60F uses 30A x 2.
Power Supply Terminal: Connect Ground Lead, Remote Turn-On Lead, and Battery Lead using the hexagon hole screw.
Ground Lead: Connect securely to a clean, bare metal spot on the chassis. Verify continuity with the battery's negative terminal. Ground all components to the same point to prevent ground loops.
Remote Turn-On Lead: Connect to the head unit's remote turn-on lead. If unavailable, use a switched power source (ACC) with a 3A fuse. The "REMOTE SENSING" function may work if the head unit's power antenna lead is used, but may not be reliable depending on the source.
Battery Lead: Add an external fuse (e.g., 80A for R2-A75M, 60A for R2-A60F) near the battery's positive terminal. Use specified wire sizes for connections.

Cautions on Wire Lead Connections:

Check wire size and use specified gauge.
Strip wire ends 7-10 mm (9/32"-13/32"). Twist wire tips.
Ensure proper exposed wire length to avoid poor connections or short circuits.
Tighten hexagon hole screws securely.
Use insulated shrink tubing to cover exposed wire.
For safety, connect battery leads last. Do not use cabling to carry the unit.

Preventing External Noise:

Route leads at least 10 cm (4") away from the vehicle's harness.
Keep battery power leads away from other leads.
Connect ground lead to a bare metal chassis spot.
Connect optional noise suppressors away from the unit. Consult your Alpine dealer for advice on noise prevention.

Connection Check List

Check your head unit for remote turn-on lead availability. If the head unit lacks a remote turn-on lead or has specific power antenna lead behaviors, connect the amplifier's remote turn-on lead to a switched power source (ignition) via a 3A fuse. An optional SPST switch can be installed for manual control. Ensure the switch is off when the vehicle is not running to prevent battery drain.

Switch Settings

Before switching, turn off the power and use a small screwdriver. Access switches by removing the top cover.

R2-A75M Switches/Controls:

Auto Turn-on Switch: Select "DC" for DC offset detection or "REM" for remote turn-on signal.
Input Level Switch: Set to "LO" for pre-out RCA input, "HI" for speaker-level input via RCA conversion cable.
Subsonic Filter Adjustment Knob: Cuts ultra-low frequencies (below specified frequency) at 24 dB/octave to protect speakers and prevent wasted power.
Crossover Frequency Adjustment Knob (LP FILTER): Adjusts crossover frequency from 50 Hz to 400 Hz.
Bass EQ Adjustment Knob: Adds up to +12 dB bass boost at 50 Hz.
Input Gain Adjustment Knob: Adjust gain to match head unit output without distortion.

R2-A60F Switches/Controls:

Filter Mode Selector Switch (CHANNEL-1/2):

OFF: Full frequency bandwidth output.
HP: High-Pass Filter (50 Hz - 400 Hz) for tweeters/midrange.
LP: Low-Pass Filter (50 Hz - 400 Hz) for subwoofers.

Crossover Frequency Adjustment Knob (HP/LP FREQ.): Adjusts crossover frequency from 50 Hz to 400 Hz.
Crossover Frequency Adjustment Knob (HP-H FREQ.): Adjusts crossover frequency from 400 Hz to 6 kHz for tweeter systems.
Input Channel Selector Switch (CHANNEL-3/4): Select "1/2" to copy CH-1/2 signal to CH-3/4, or "3/4" for independent CH-3/4 input (requires 4-channel source).
Filter Mode Selector Switch (CHANNEL-3/4):

OFF: Full frequency bandwidth output.
HP: High-Pass Filter (50 Hz - 400 Hz) for tweeters/midrange.
LP: Low-Pass Filter (50 Hz - 400 Hz) for subwoofers.
BP: Band-Pass Filter, attenuates frequencies below a set point (controlled by Knob 12) and above another set point (controlled by Knob 13).

Crossover Frequency Adjustment Knob (HP/LP/BP-L FREQ.): Adjusts crossover frequency from 50 Hz to 400 Hz. Used with BP mode for lower cutoff.
Crossover Frequency Adjustment Knob (BP-H FREQ.): Adjusts crossover frequency from 400 Hz to 6 kHz. Used with BP mode for upper cutoff.

Power Indicator

The power indicator lights up when the unit is on and is off when it is off.

Blue: Amplifier circuit is normal.
Red (blinking): Operating temperature is high. Turn down volume or cool the vehicle interior.
Red: Amplifier circuit is abnormal (short circuit, high current) or power supply voltage is too high. Turn off power, eliminate cause, and consult dealer if problem persists.

System Diagrams

Various connection diagrams are provided to illustrate setups for different speaker configurations, including subwoofer systems, multi-speaker systems, and bridged connections for both R2-A75M and R2-A60F amplifiers. These diagrams detail the connection of speakers, head units, power sources, and control signals using the amplifier's terminals and specified cables.

Key connection types illustrated include:

Subwoofer Systems (single, dual, dual voice coil)
4 Speaker + Subwoofer / 2 Amplifier Systems
2 Speaker Systems (Bridged Connections)
Front 2-Way Systems
Front 2-Way + Subwoofer / 2 Amplifier Systems

Instructions are given for setting input level switches and channel selector switches based on the system configuration.

Connecting to Speaker Input Level System: Use the Speaker-RCA Conversion Cable and set the Input Level Switch to "HI". The "REMOTE SENSING" function may not require a separate remote turn-on lead connection.

Bridging an Amplifier: Proper connection using stereo/mono pair line outputs is crucial for bridged operation. Using only one channel input may result in low output.

Cautions on Power Supply Wires

Use specified wire sizes according to total fuse capacity and wire length. Examples are provided for installing a single amplifier or multiple amplifiers, detailing wire gauge (AWG/mm²) and external fuse capacity requirements. A distribution block is recommended for multiple amplifiers or long cable runs.

Specifications

R2-A75M

Performance
Power Output	Per Channel, Ref.: 4 Ω, 14.4 V	500 W RMS × 1
	Per Channel, Ref.: 2 Ω, 14.4 V	750 W RMS × 1
THD+N	Ref.: 10 W into 4 Ω	≤0.04%
	Ref.: 10 W into 2 Ω	≤0.06%
	Ref.: Rated Power into 4 Ω	≤1.0%
	Ref.: Rated Power into 2 Ω	≤1.0%
S/N Ratio	IHF A-wtd + AES-17 Ref.: 1 W into 4 Ω	>75 dB
	IHF A-wtd + AES-17 Ref.: Rated Power into 4 Ω	>102 dB
Frequency Response	+0/-3 dB, Ref.: 1 W into 4 Ω	10 Hz - 400 Hz
	+0/-1 dB, Ref.: 1 W into 4 Ω	15 Hz - 325 Hz
Damping Factor	Ref.: 10 W into 4 Ω at 100 Hz	>250
Control	RCA Input Ref.: Rated Power into 4 Ω	Hi: 0.4 - 10 V Lo: 0.1 - 4.0 V
Crossover	Variable LPF	50 Hz - 400 Hz (-24 dB/oct.)
	Variable Subsonic	8 Hz - 40 Hz (-24 dB/oct.)
Equalizer	Bass EQ (fc=50 Hz)	0 to +12 dB (Variable)
Remote Level*	Linear Attenuation	0 to -20 dB
General	Input Impedance	>10 kΩ
	Preamp Output	CH-1/2 Input Pass-through, Buffered, 4 V max
Dimensions	Width	282 mm (11-1/8")
	Height	55 mm (2-3/16")
	Depth	165 mm (6-1/2")
Weight		3.5 kg (7 lb 10 oz)

* Requires optional RUX-KNOB.2.

R2-A60F

Performance
Power Output	Per Channel, Ref.: 4 Ω, 14.4 V	100 W RMS × 4
	Per Channel, Ref.: 2 Ω, 14.4 V	150 W RMS × 4
	Bridged, Ref.: 4 Ω, 14.4 V	300 W RMS × 2
THD+N	Ref.: 10 W into 4 Ω	≤0.04%
	Ref.: 10 W into 2 Ω	≤0.06%
	Ref.: Rated Power into 4 Ω	≤0.5%
	Ref.: Rated Power into 2 Ω	≤1.0%
S/N Ratio	IHF A-wtd + AES-17 Ref.: 1 W into 4 Ω	>80 dB
	IHF A-wtd + AES-17 Ref.: Rated Power into 4 Ω	>100 dB
Frequency Response	+0/-3 dB, Ref.: 1 W into 4 Ω	10 Hz - 45 kHz
	+0/-1 dB, Ref.: 1 W into 4 Ω	20 Hz - 20 kHz
Damping Factor	Ref.: 10 W into 4 Ω at 100 Hz	>100
Control	Input Select	CH-3/4: CH-1/2 or CH-3/4
	Input Sensitivity	RCA Input Ref.: Rated Power into 4 Ω	Hi: 0.5 - 10 V Lo: 0.2 - 4.0 V
Crossover	Variable HPF/LPF/HPF-H	CH-1/2: HPF/LPF: 50 Hz - 400 Hz (-12 dB/oct.) HPF-H: 400 Hz - 6 kHz
	Variable HPF/LPF/BPF	CH-3/4: HPF/LPF/BPF-L: 50 Hz - 400 Hz BPF-H: 400 Hz - 6 kHz (-12 dB/oct.)
Remote Level*	Linear Attenuation	CH-3/4: 0 to -20 dB
General	Input Impedance	>10 kΩ
Dimensions	Width	282 mm (11-1/8")
	Height	55 mm (2-3/16")
	Depth	165 mm (6-1/2")
Weight		3.3 kg (7 lb 3 oz)