BOSS RIOT MOSFET 4-Channel Power Amplifiers

Introduction

With the BOSS RIOT MOSFET amplifier series, BOSS Audio Systems introduces thirteen new amplifiers, all designed in the USA. This new series includes four 4-channel amplifiers: R2504M, R3004M, R4004M, and R5004M.

All RIOT models feature variable low pass and high pass crossovers and variable input gain controls. They also incorporate an input voltage sensitivity selector for added system flexibility.

For further flexibility in the use of a subwoofer, a 0-+18dB Bass Boost control has been included on all amplifiers. You can control the subwoofer level with the remote level control module.

BOSS Audio Systems understands that amplifiers are placed in many different kinds of installations, so we incorporated a very flexible system of controls in these amplifiers in order to help you integrate the amp into your system regardless of the nature of your input source.

What is Included?

When first unpacking your new amplifier, please check first that the package contains all of the items below. If something is missing, contact the store where you purchased the amplifier.

• RIOT Amplifier
• Remote subwoofer level control
• High input cable with connector
• Four (4) mounting screws

Features

Your new RIOT amplifier features the following:

• Class A-B operation
• Bridgeable outputs
• Tri-Mode capable
• MOSFET PWM (Pulse Width Modulated) Power Supply
• 2 Ohm stable stereo operation with output power increase
• Thermal and speaker short protection
• Soft turn-on circuit
• Remote turn-on/turn-off circuit
• Variable input gain control
• Variable low pass crossover(s)
• Fixed high pass crossover(s)
• Variable 0 to +18dB Bass Boost
• Nickel-plated RCA low level and high level inputs
• LED power and protection indicators
• Black anodized heatsink
• Remote subwoofer level control

About 2 Ohm Operation

Your RIOT amplifier has been designed to operate efficiently at loads down to 2 Ohms. This means that you can install four 8 Ohm speakers per channel, when using parallel wiring.

Doubling the number of woofers produces an acoustic coupling effect. This acoustic coupling effect increases the output by about 3dB for each doubling of the number of woofers.

When operating at 2 Ohms, the amplifiers will increase their output power by approximately 50%. The current draw will also increase by about the same amount, so be sure you have enough current to run the amplifiers into a 2 Ohm load.

If you lack adequate current, your music reproduction will be distorted.

General Precautions

Before installing and using your new BOSS amplifier, please become familiar with all the information contained in this manual. Please keep this manual in a safe place for future reference.

• Do not open or attempt to repair this unit yourself. Dangerous high voltages are present which may result in electric shock. Refer any repairs to a qualified service technician.
• To avoid risk of electronic shock or damage to the amplifier, do not permit any of this equipment to become damp or wet from water or drinks. If this does occur, immediately unplug the power wires and send the amplifier to your local dealer or service center as soon as possible.
• If there is smoke or any peculiar odor present during use or if there is damage to any of the component enclosures, immediately unplug the power wire and send the amplifier to your local dealer or service center as soon as possible.

Before making or breaking power connections in your system, disconnect the vehicle battery. Confirm that your head unit or other equipment is turned off while connecting the input jacks and speaker terminals.

If you need to replace the power fuse, replace it only with a fuse identical to that supplied with the amplifier. Using a fuse of a different type or rating may result in damage to your audio system or your amplifier which is not covered by the manufacturer's warranty.

Installation Precautions

Before you drill or cut any holes, investigate your car's layout very carefully. Take special care when you work near the gas tank, fuel lines, hydraulic lines and electrical wiring.

Never operate the amplifier when it is unmounted. Attach all audio system components securely to prevent damage, especially in an accident.

SHOCK HAZARD! Do not open the case of this product. There are dangerous voltages present within the unit. There are no user-serviceable parts within the unit.

Mounting the Amplifier

1. Find a suitable location in the vehicle in which to mount the amplifier.
2. Make sure there is sufficient air circulation around the intended mounting location.
3. Mark the location for the mounting hole screws by positioning the amplifier where you wish to install it. Use a scribe or mounting screw, inserted through each of the amp's mounting holes, to mark the mounting surface. If the mounting surface is carpeted, measure the hole centers and mark with a felt tip pen.
4. Drill pilot holes in the mounting surface for the mounting screws. Place the amplifier in position, and attach the amplifier to the mounting surface securely using screws.

Power and Speaker Wiring

4-Channel Mode

This mode connects speakers to individual channels (CH1, CH2, CH3, CH4). Speaker impedance should be between 2-8 Ohms for CH1/CH2 and CH3/CH4.

Power Connections:

• Connect the BATT+ terminal to the vehicle's battery via an inline fuse (rated appropriately, e.g., 25A for R2504M, 30A for R3004M, 35A for R4004M/R5004M). The fuse should be within 18" (45 cm) of the battery.
• Connect the REMOTE terminal to the remote output of the head unit using 16 gauge wire.
• Connect the GROUND terminal to a solid chassis ground point using 8 gauge (or heavier) wire, no longer than 39" (100 cm).

Speaker Connections:

• CH1 Speaker: Connect to the positive (+) terminal of the left front speaker.
• CH1 Speaker (-): Connect to the negative (-) terminal of the left front speaker.
• CH2 Speaker: Connect to the positive (+) terminal of the left rear speaker.
• CH2 Speaker (-): Connect to the negative (-) terminal of the left rear speaker.
• CH3 Speaker: Connect to the positive (+) terminal of the right front speaker.
• CH3 Speaker (-): Connect to the negative (-) terminal of the right front speaker.
• CH4 Speaker: Connect to the positive (+) terminal of the right rear speaker.
• CH4 Speaker (-): Connect to the negative (-) terminal of the right rear speaker.

Diagram Description (Four Channel Mode): The diagram illustrates the amplifier's terminal layout for 4-channel mode. Power connections include BATT+ (positive battery terminal), REMOTE (for head unit turn-on signal), and GROUND (chassis ground). Speaker outputs are clearly labeled for CH1, CH2, CH3, and CH4, with positive (+) and negative (-) terminals for each channel. Minimum speaker impedance is noted as 2-8 Ohms for CH1/CH2 and CH3/CH4.

Bridged Mode

This mode allows for higher power output by combining two channels into one. It is typically used for subwoofers.

Power Connections: Same as 4-Channel Mode.

Speaker Connections:

• Connect the LEFT Subwoofer to CH1 (+) and CH2 (-).
• Connect the RIGHT Subwoofer to CH3 (+) and CH4 (-).

Minimum speaker impedance for bridged mode is 4 Ohms.

Diagram Description (Bridged Mode): The diagram shows how to configure the amplifier for bridged mode. For the left subwoofer, the positive (+) terminal connects to CH1 and the negative (-) terminal connects to CH2. For the right subwoofer, the positive (+) terminal connects to CH3 and the negative (-) terminal connects to CH4. Minimum speaker impedance for bridged mode is 4 Ohms. Power connections remain the same as 4-channel mode.

Tri-Mode Operation

Tri-mode operation allows you to connect this amplifier to a pair of main speakers plus a subwoofer on one pair of output channels. The main speakers will operate in STEREO while the subwoofer simultaneously operates in MONO.

To set up the amplifier to run in this mode, put the crossover switches in the FULL position. Insert high pass filter capacitors and a low pass filter inductor into the wiring as shown below. Be sure to check the table at the bottom of this page to determine the correct capacitor and inductor values for the crossover frequency you wish to achieve.

Component Values for 6dB Passive Crossover:

Diagram Description (Tri-Mode): This diagram details the Tri-Mode setup. It shows how to connect main speakers to CH1 and CH2, and a subwoofer to CH3 or CH4. Crucially, it indicates the placement of a low-pass filter inductor in the subwoofer line and a high-pass filter crossover in the main speaker lines. Component values for these filters are provided in a separate table. Power connections are also shown.

Connecting the Amplifier

Before doing any wiring, look through this manual and identify the diagrams to follow for power, input and speaker connections for your particular installation. Be sure you understand all the connections before you proceed.

1. Connect the power ground terminal to the closest point on the chassis of the car. Keep this ground wire to less than 39" (100 cm) in length. Use 8 gauge (or heavier) wire.
2. Connect the remote terminal to the remote output of the head unit using 16 gauge (or heavier) wire.
3. Connect an empty fuse holder within 18" (45 cm) of the car battery, and run 8 gauge (or heavier) cable from this fuse to the amplifier location.
4. Check that the fuse holder is empty. Then connect the fuse holder to the "BATT+" connection on the amplifier.
5. If multiple amplifiers are being used in your system, either:
   • Run a separate pair of cables from the battery and a chassis ground point to each amplifier. Each (+) cable must have its own inline fuse.
   • Run a #4 cable from the fuse holder at the battery to a distribution block at or near the amplifier's location. Then run separate cables from the amplifier to this distribution block and to independent chassis ground points.
6. Connect all line inputs and outputs (if used) using high-quality cables. Connect all speakers, following the diagrams in this manual. Be sure to observe proper polarity to avoid audio phase problems.
7. Insert fuse(s) into the battery fuse holder(s).
8. Recheck all connections before powering up the amplifier.
9. Set all level controls to minimum position, and set all crossover controls/switches to the desired frequency points.
10. Power up the head unit and the amplifier. Then set the volume control on the head unit to about 3/4 volume, and adjust the amplifier's input level control(s) to just below the level of distortion.
11. Further fine tuning of the various controls may be necessary to obtain best results.

Don't misuse the level control!

Do not mistake the input level control for a volume control! It is designed ONLY to match the output level of your audio source to the input level of your amplifier.

Do not adjust this input level to maximum unless your input level requires it.

Ignoring these instructions will result in an input overload to the amplifier, and excessive audio distortion. It can also cause the protection circuit to engage.

Low Level Input Wiring

Low-level (RCA) input wiring is preferred for best audio performance. Always use a high-quality RCA cable for best audio performance.

NOTE: Do not connect BOTH the high level and low level inputs from your receiver to your amplifier at the same time!

Diagram Description (Low Level Input): The diagram illustrates low-level (RCA) input connections. It shows RCA cables from the 'FRONT Audio Outputs' of a head unit or signal processor connecting to the CH1/CH2 LOW LEVEL INPUTS on the amplifier. Similarly, 'REAR Audio Outputs' connect to the CH3/CH4 LOW LEVEL INPUTS. The Remote Subwoofer Level Control is also shown connected.

High Level Input Wiring

The high level input(s) should only be used when your head unit lacks RCA outputs. If the RCA outputs are not present, connect the speaker outputs from the receiver to the high level input connector of the amplifier. Be sure to observe polarity to avoid audio phase problems.

NOTE: Do not connect BOTH the high level and low level inputs from your receiver to your amplifier at the same time!

Diagram Description (High Level Input): This diagram depicts high-level input wiring. It shows speaker wires from the 'Speaker Terminals of a head unit' connecting to the HIGH LEVEL INPUT connector on the amplifier. This method is used when the head unit lacks RCA outputs. The Remote Subwoofer Level Control is also shown connected.

Troubleshooting

If you experience operation or performance problems with this product, compare your installation with the electrical wiring diagram on the previous pages. If problems persist, read the following troubleshooting tips which may help eliminate the problems.

Specifications

4-Channel MOSFET Amplifiers

All specifications subject to change without notice.