Rockville ATOM S20 & S30 4-Channel Class AB Marine Amplifier Owner's Manual

Introduction

Thank you for purchasing the Rockville ATOM S Series Class AB Marine Amplifier. Rockville is committed to developing the latest technologies to bring you the best-sounding amplifiers at a reasonable price. These amplifiers are designed to be rugged, reliable, powerful, and best-performing, backed by a one-year warranty.

Please read this entire guide fully before attempting installation. For assistance, contact the Rockville technical help line at 1-646-758-0144, Monday-Thursday, 9am-10pm EST, and Fridays, 9am-3pm EST.

NOTE: All information in this manual applies to both ATOM S models (S20 and S30) unless otherwise noted.

Important Safety Instructions

CAUTION: RISK OF ELECTRIC SHOCK. DO NOT OPEN.

WARNING: Prolonged exposure to extreme high volumes may cause hearing loss or damage. Always keep sound volume at reasonable levels.

• Secure the amplifier tightly during installation to prevent injury or damage from abrupt maneuvers or sudden stops.
• Do not open the unit; there are no serviceable parts. Refer service to an authorized Rockville service center.
• Ensure the unit is situated in a properly ventilated area.

Installation

Installation Basics

Before installation, disconnect the NEGATIVE (-) terminal from your vessel's house battery to avoid short circuits. Rockville amplifiers operate on 12-volt negative ground systems only. It is recommended to lay out your sound system design on paper first to create a wiring flow chart.

Mounting The Amplifier

The ATOM S series amplifiers have four mounting feet. Mount the amplifier in a convenient location with unobstructed airflow, such as the rear of the vessel, underneath the dashboard, or below the seats. Mark the mounting hole locations, drill pilot holes (being careful of gas tanks, lines, and electrical lines), and secure the amplifier with the supplied screws. Do not overtighten screws.

IMPORTANT: Due to vessel vibrations, periodically tighten all power and ground connections.

Diagram Description: The diagram shows the mounting feet of the amplifier being attached to a surface with screws.

Wiring

1. Disconnect the NEGATIVE (-) terminal from your vessel's house battery.
2. Connect an 8-gauge or heavier wire to the amplifier's GND terminal and the other end to the vessel's NEGATIVE (-) terminal. For runs over 20 feet, use 4-gauge or heavier wire. Ensure a good ground connection, free of paint or insulation. For multiple amplifiers, mount them close together to share a ground point.
3. Connect the remote terminal to the head unit's remote output (or power antenna lead if no remote output exists) using 18-gauge or heavier wire. This turns the amplifier on/off with the system. If no turn-on leads are available, connect to an accessory lead that activates with the vessel's ignition.
4. Connect an 8-gauge or heavier wire from the vessel's POSITIVE (+) terminal to the +12V terminal. Install an in-line fuse holder within 18 inches of the battery for protection. Use a large ring terminal for the connection to the POSITIVE (+) terminal. For multiple amplifiers, use a distribution block.
5. Insert fuses into the in-line fuse holder(s) and ensure all connections are secure.
6. Before powering up, set all amplifier level controls to minimum, crossover/setting switches to desired positions, and head unit volume to 75%.

Diagram Description: The diagram illustrates the wiring connections for the amplifier, showing power (+12V), ground (GND), and remote (REM) terminals connected to the house battery and head unit, with fuses indicated.

Speaker Wiring

NOTE: Use spade connectors for best performance.

Diagram Description: The diagram shows how to prepare speaker wire by stripping sheathing and attaching a spade connector, then connecting it to the speaker terminals.

Use 16-gauge speaker wire for speaker connections. Speaker terminal size is 10-gauge.

Use 8-gauge power and ground cables. Use 18-gauge wire for remote connection. Power and ground terminal size is 4-gauge.

Settings

Adjusting the System

1. Set all crossover points to approximate settings. For a subwoofer system, set the Low Pass Filter (LPF) crossover around 100Hz and Bass EQ to 0dB (Channels 3-4). Use a small flathead screwdriver and do not apply excessive pressure.
2. Set the Input Sensitivity (LEVEL controls) by turning them counterclockwise to MIN. Adjust your head unit's volume to maximum before signal distortion (typically 75%-85%). Turn the amplifier's LEVEL control clockwise until distortion is heard, then back off one notch. For multi-amp systems, set each amplifier's level controls individually, starting with the bass amplifier. The LEVEL control is not a volume control; it matches the source unit's output to the amplifier's input.
3. Use equalizer controls to adjust the system's tonal level. You may need to reset amplifier level controls after equalization.

Professional Installation Note: If your unit was professionally installed, do not change the gain settings set by the installer.

Using the Electronic Crossovers

ATOM S Series marine amplifiers feature adjustable 12dB/octave low-pass, high-pass, and full-range electronic crossovers.

• For low-pass systems: Set Channel 3 & 4 X-OVER MODE to LPF and Channel 1 & 2 X-OVER MODE to CLONE (for bridged systems). The LPF control for Channels 3 & 4 adjusts frequencies from 50Hz – 250Hz. For most installations, do not set the frequency lower than 80Hz.
• For coaxial or component speakers: Set all X-OVER MODE selectors to FULL or HIGH PASS. The HPF control adjusts frequencies from 50Hz – 250Hz.

Audio Preamp Input

Use high-quality, shielded RCA patch cords for preamp inputs to minimize electrical noise. Run RCA cables on the opposite side of the vessel from power and ground leads.

Input Configurations

4-Channel Amp in 2-Channel Mode

If your head unit has one pair of RCA outputs, connect them to Channels 1 & 2. Set the Input Mode switch to 2CH. The amplifier will automatically mix signals to Channels 3 & 4.

Diagram Description: Shows a source unit connected to the amplifier's Channels 1 & 2 inputs, with the Input Mode switch set to 2CH.

4-Channel Amp in 4-Channel Mode

If your head unit has two pairs of RCA outputs, connect Front Left/Right to Channels 1 & 2, and Rear Left/Right to Channels 3 & 4. Set the Input Mode switch to 4CH.

Diagram Description: Shows a source unit connected to the amplifier's Channels 1 & 2 and Channels 3 & 4 inputs, with the Input Mode switch set to 4CH.

Output Configurations

4-Channel Amp in 4-Channel Mode

Install component or coaxial speakers (minimum impedance 2 ohms) on Channels 1-4. For typical speaker installs, set Crossover Mode Switches to Full Range.

Diagram Description: Illustrates connecting component or coaxial speakers to Channels 1-4, with crossover mode switches set to Full Range.

4-Channel Amp in 3-Channel Mode

Connect component or coaxial speakers (minimum impedance 2 ohms) to Channels 1 & 2. Bridge Channels 3 & 4 for a subwoofer (minimum impedance 4 ohms). Set Channels 1 & 2 X-OVER MODE to Full Range, and Channels 3 & 4 X-OVER MODE to LPF.

Diagram Description: Shows speakers connected to Channels 1 & 2, and a subwoofer bridged to Channels 3 & 4, with appropriate crossover settings.

4-Channel Amp in 2-Channel Bridged Mode

Bridge Channels 1 & 2 for one woofer (positive to Channel 1, negative to Channel 2). Bridge Channels 3 & 4 for another woofer (positive to Channel 3, negative to Channel 4). Set the Channel 1-2 Crossover Mode Switch to CLONE and the Channel 3-4 Crossover Mode Switch to LPF.

Diagram Description: Illustrates bridging pairs of channels for subwoofers, with specific crossover mode switch settings.

RCA Outputs

The RCA pre-amp line outputs can feed a full-range signal to a secondary amplifier in a multi-amp system.

Diagram Description: Shows two configurations for using RCA outputs: 2-Channel Output/2-Channel Input and 2-Channel Output/4-Channel Input.

Public Address System

These marine amps feature a public address system with microphone and talk-over functionality. Connect the included microphone to the 3.5mm jack marked MIC. When the microphone is keyed, music fades to the background. Adjust microphone volume using the knob on the microphone.

Diagram Description: Shows a microphone and its connection point on the amplifier.

Bluetooth (S20 only)

Pairing

Place the Bluetooth switch to ON. The Bluetooth status LED will flash blue. Find and select "ATOM BT" on your device. The LED will turn solid blue upon successful pairing.

Operation

Browse, play, pause, and control volume from your device. To disconnect, disable Bluetooth on your device and set the amplifier's Bluetooth switch to OFF.

Diagram Description: Shows the Bluetooth switch and status LED on the amplifier.

Features

• Bass Equalization Circuitry: A preset 45Hz equalization circuit allows up to 12dB of bass boost. Use to tailor bass response, ensuring speakers can handle the extra power.
• Audio Output Section: Features studio-grade, high-current Bi-Polar audio transistors for clean, low-distortion output.
• Power and Protection Circuitry: Unique IC-controlled protection monitors internal temperature and voltages, adjusting the amp automatically. A status LED indicates amplifier status (green for normal, red for diagnostic condition). The amplifier enters self-preservation mode and may shut down if a diagnostic condition persists.
• Thermal Protection: Shuts off the amplifier at 80°C (176°F). It will automatically restart when cooled. Consider additional cooling fans in hot climates or enclosed spaces.
• Speaker Short Circuit Protection: Detects speaker short circuits or low impedance. The status LED turns red. Turn off the system, disconnect speakers one by one to identify the fault, correct it, and restart the amplifier (turn OFF/ON via remote power).
• Input Overload Protection: May cause the amplifier to shut down or spurt on/off. Turn off the system and reduce amplifier gain or head unit volume.
• DC Offset Protection: Prevents DC voltage at speaker terminals, protecting speakers from damage.
• Resetting the Amplifier: After correcting a diagnostic condition, reset the amplifier by turning it OFF and then ON again. If the problem persists, the amplifier may be faulty.
• Mute Circuit: An anti-thump, mute, and delay circuit eliminates irritating turn-on/turn-off transients.
• Battery Voltage: Rated for 13.8V and below. Increasing voltage to 14.4V increases power output. Maximum input voltage is 14.4V, minimum is 12V.

Specifications

S20

• Dyno Certified RMS Power Output: 110W x 4 @ 2 Ohms, 70W x 4 @ 4 Ohms, 220W x 2 @ 4 Ohms Bridged (all <1% THD+N @ 14.4V)
• Peak Power Output: 400W x 4 @ 2 Ohms, 260W x 4 @ 4 Ohms, 800W x 2 @ 4 Ohms Bridged
• Low Pass Filter: 50Hz – 250Hz
• High Pass Filter: 50Hz – 250Hz
• Minimum THD at Rated Power: <0.05%
• S/N Ratio: >90dB
• Frequency Response: 10Hz - 50kHz
• Damping Factor: >85 @ 100Hz
• Fuses: 2 x 25 Amp ATC
• Dimensions (W x H x L): 6.7" x 2" x 11.6"

S30

• Dyno Certified RMS Power Output: 150W x 4 @ 2 Ohms, 100W x 4 @ 4 Ohms, 300W x 2 @ 4 Ohms Bridged (all <1% THD+N @ 14.4V)
• Peak Power Output: 600W x 4 @ 2 Ohms, 400W x 4 @ 4 Ohms, 1200W x 2 @ 4 Ohms Bridged
• Low Pass Filter: 50Hz – 250Hz
• High Pass Filter: 50Hz – 250Hz
• Minimum THD at Rated Power: <0.05%
• S/N Ratio: >90dB
• Frequency Response: 10Hz - 50kHz
• Damping Factor: >85 @ 100Hz
• Fuses: 2 x 40 Amp ATC
• Dimensions (W x H x L): 6.7" x 2" x 14.7"

Additional Features (Both Models)

• High-Speed MOSFET Power Supply
• Tertiary Supplies Circuit
• Digital Voltage Display
• Built-in Bluetooth wireless audio streaming (S20 only)
• Optical Coupler Class "AB" Technology
• Fully Adjustable 12dB/Octave Crossover with Differential Circuitry
• 2CH/4CH Input Mode Switch
• Input Level Control
• RCA Input
• 8-Volt Preamp Circuitry
• Under Voltage Protection at 10V
• Over Voltage Protection at 16V
• All channels have bridgeable crossovers
• 4 Gauge power and ground terminals; 10 Gauge speaker wire terminals
• Painted Conformal Coating PCB Board
• Rustproof aluminum heatsink with dark grey anodized finish
• Stainless steel end panels and mounting hardware
• Bottom panel is aluminum
• Microphone Input (PA Microphone included)

Woofer Wiring Guide

SVC Configurations: Minimum impedance load is 2-ohm stereo and 4-ohm mono bridged. Do not mix different impedance speakers in series/parallel combinations.

Diagram Description: Various diagrams illustrate wiring configurations for Single Voice Coil (SVC) woofers with different impedances (2Ω, 4Ω, 8Ω) to achieve desired load impedances.

DVC Configurations:

Diagram Description: Various diagrams illustrate wiring configurations for Dual Voice Coil (DVC) woofers with different impedances (2Ω, 4Ω) to achieve desired load impedances.

Troubleshooting

Amp goes into protect mode

• Short circuit protection: Check power, ground, and remote wire connections. Ensure proper voltage (12-14.4V) from the power wire and 5V from the remote wire.
• Thermal protection: Amplifier overheats. Check subwoofer compatibility and wiring.
• Blown speaker: Disconnect speakers; if protect mode clears, a speaker is faulty.
• Wrong speaker impedance: Replace speakers with correct impedance.
• Speaker wires touching: Ensure positive and negative wires do not touch at terminals.
• Reverse polarity protection: Correctly connect positive and negative speaker wires.
• Power wire gauge: Ensure power and ground wires are of sufficient gauge.
• RCA cables: Faulty RCA cables can trigger protect mode. Test with known good cables.

Note: Reset the amplifier by turning it OFF and then ON again after correcting a condition.

Amp won't power on

• Ensure external fuse is properly seated and making contact.
• Replace blown external fuse with one of the correct value.
• Check ground wire for secure connection.
• Check power wire connection to ring terminal; clean corrosion if present.
• Verify power wire is connected to the correct positive/negative terminals.
• Ensure remote turn-on wire is securely connected to the amplifier and receiver's remote turn-on terminal (not the antenna wire).
• Verify power wire is connected to the +12V terminal, not the ground terminal.
• Check power or ground wires for looseness.

Power but no sound

• Check for active protection lights; refer to protection circuitry sections.
• Ensure RCA cables are plugged into the RCA input, not output.
• Test RCA cables with a spare or multimeter.
• Verify speaker wire connections at the amplifier and speaker terminals are secure.
• Ensure correct polarity for speaker wires.
• Turn up the amplifier's gain.
• Check receiver settings for disabled RCA outputs or fader/balance controls affecting preamp outputs. Enable front, rear, and sub preamp outputs.

Amp is clipping

• Speakers/subs may be too powerful for the amplifier; check compatibility.
• Speakers/subs wired at lower impedance than recommended can cause clipping. Wire at the proper impedance.
• Gain setting too high: Turn receiver volume to 75%, slowly increase amp gain until slight distortion, then back off one notch. Gain is not a volume control.
• Poor ground cable connection can cause clipping. Ensure it's tight.
• Power and ground wires may be too thin. Use the proper gauge wires.
• If using multiple devices with volume controls (equalizer, processor, receiver, amp), lower the volume on one or two devices.

Distortion, background noise, crackling, or hissing

• Check wire routing: Run RCA cables and speaker wires separately from power cables to prevent feedback.
• Poor ground cable connection can cause noise. Ensure it's tight.
• Engine noise: Install a ground loop isolator on the receiver's power lead or ensure ground connections are tight.
• Gain setting too high or high receiver preamp voltage can cause noise. Set gain appropriately (e.g., receiver volume at 75-80%, slowly adjust amp gain until hiss is minimal).
• Bad RCA cables can pick up noise. Test with different RCA cables.
• Low-quality speaker wires can cause noise. Use high-quality insulated speaker wire.

Sound is too low

• Wiring at too high an impedance can result in low power output. Wire speakers/subs properly.
• Increase the amplifier's gain level.
• Thin power and ground wires can cause low sound. Use the proper gauge wires.
• Ensure speaker wires are not reversed.
• Check crossover settings; filter out high frequencies if necessary, or lower the low-pass crossover frequency.
• Adjust receiver preamp output level controls (subwoofer, front, rear).
• Amplifier may not be powerful enough; consider upgrading.

Amp keeps blowing fuses

• Main Fuse: If fuse blows immediately with everything off, check for a short in the power cable between the fuse and the distribution block or amplifier.
• Distribution Block Amp Fuse: If power is present on one side of the fuse but not the other, check for a shorted power wire or internal amplifier fault. Disconnect the power wire from the amp and check if the fuse still blows.
• Internal Amplifier Fuse: If the fuse blows when the amp is turned up, check subwoofer compatibility and impedance. Rewire for proper impedance or replace subwoofers. Ensure power/ground wires are not crossed.

Amp gets very hot

• Overheating is often caused by very low impedance loads or insufficient power for the subwoofer. Ensure proper impedance and wiring, and use compatible subwoofers.
• A poor ground cable connection can cause overheating. Ensure it's tight.
• Ensure the amplifier is mounted in a location with proper ventilation.

Amp or powered sub does not turn off

• Remote turn-on wire may be connected to a constant 12V power wire instead of the receiver's remote turn-on terminal. Reconnect correctly.
• Remote turn-on wire may be touching the power wire. Ensure it is properly seated and not making contact.

One channel on the amp isn't working

• Test RCA cables with a spare or multimeter.
• Ensure RCA cables are plugged into the correct preamp outputs (red/white) on the receiver, not the video input (yellow).
• Check receiver settings that might disable RCA outputs or affect preamp outputs. Enable all relevant preamp outputs.
• Ensure speaker wire connections at the amplifier and speaker terminals are secure.
• Verify correct polarity for speaker wires.
• Ensure the amplifier's gain is turned up.

Installation Notes

Space for user notes.