Introduction
Thank you for choosing the Nemesis Audio NA-2.5KD Monoblock Car Audio Stereo Amplifier. This manual provides detailed instructions for the proper installation, operation, and maintenance of your amplifier. Please read this manual thoroughly before attempting installation or operation to ensure optimal performance and safety.
Safety Information
Always observe the following safety precautions during installation and operation:
- Disconnect the vehicle's negative battery terminal before starting any electrical work.
- Ensure all wiring is properly routed and secured to prevent damage or short circuits.
- Use appropriate gauge wiring for power and ground connections as specified in this manual.
- Install the amplifier in a location that allows for adequate ventilation and is protected from moisture and excessive heat.
- Do not operate the amplifier if it is damaged or malfunctioning. Refer to the troubleshooting section or contact qualified service personnel.
- High sound pressure levels can cause permanent hearing loss. Adjust volume levels responsibly.
Package Contents
Verify that your package contains the following items:
- Nemesis Audio NA-2.5KD Monoblock Amplifier
- User Manual (this document)
- Mounting Hardware (screws, etc.)
If any items are missing or damaged, please contact your dealer immediately.
Product Features
The Nemesis Audio NA-2.5KD amplifier offers the following key features:
- High power handling: Up to 2500 Watts Max Power.
- Adjustable Bass Boost Frequency: 30 - 80Hz.
- Adjustable Subsonic Filter: 5 - 50Hz.
- Low Pass Filter (LPF): 40 - 180 Hz.
- Variable Input Sensitivity: 0.2 - 5V.
- Stable operation at 1-Ohm impedance.
Component Identification
Familiarize yourself with the various components and controls of your NA-2.5KD amplifier.
Top View
Figure 1: Top view of the Nemesis Audio NA-2.5KD amplifier, displaying the Nemesis Audio logo, model number NA-2.5KD, and '2500W MAX' indicating its maximum power output. The amplifier features a brushed black finish with ventilation grilles.
Power and Speaker Terminals
Figure 2: Rear panel of the amplifier showing the power input terminals (+12V, REM, GND) on the right and speaker output terminals (SPEAKER +, -) on the left. The speaker terminals indicate a 1 Ohm minimum impedance. All terminals are screw-type for secure connections.
- +12V: Main power input from the vehicle battery.
- REM (Remote): Connects to the head unit's remote turn-on output.
- GND (Ground): Connects to the vehicle's chassis ground.
- SPEAKER: Output terminals for connecting to subwoofers.
Control Panel
Figure 3: Side panel of the amplifier featuring RCA input and output jacks, along with various control knobs. From left to right, these include PROTECT and POWER indicator LEDs, REMOTE port, INPUT (RCA L/R), BRIDGE IN (RCA L/R), GAIN control, LPF (Low Pass Filter) control, SUBSONIC filter control, BASS BOOST FREQ (Frequency) control, and BASS BOOST level control.
- POWER/PROTECT LEDs: Indicate operational status.
- REMOTE: Port for optional remote bass knob.
- INPUT (RCA): Audio signal input from the head unit.
- BRIDGE IN (RCA): Used for bridging multiple amplifiers (advanced setup).
- GAIN: Adjusts the input sensitivity of the amplifier.
- LPF (Low Pass Filter): Controls the upper frequency limit for the output.
- SUBSONIC: Filters out ultra-low frequencies below the audible range.
- BASS BOOST FREQ: Selects the center frequency for bass boost.
- BASS BOOST: Adjusts the level of bass enhancement.
Setup and Installation
Proper installation is crucial for the performance and longevity of your amplifier. If you are unsure about any part of the installation process, consult a professional car audio installer.
Mounting Location
Choose a mounting location that is:
- Secure and stable.
- Protected from moisture and direct sunlight.
- Allows for adequate airflow around the amplifier's heatsink.
- Away from fuel lines, brake lines, and electrical wiring harnesses.
Wiring Connections
1. Power Connection (+12V):
- Connect a heavy gauge power cable (e.g., 4 AWG or larger, depending on total system power) directly from the vehicle's positive battery terminal to the amplifier's +12V terminal.
- Install an in-line fuse holder within 18 inches (45 cm) of the battery. The fuse rating should match the amplifier's maximum current draw (refer to specifications).
2. Ground Connection (GND):
- Connect a heavy gauge ground cable (same gauge as power cable) from the amplifier's GND terminal to a clean, unpainted metal surface on the vehicle's chassis.
- Ensure the ground point is free of paint, rust, or dirt for a good electrical connection. The cable length should be as short as possible, ideally less than 3 feet (1 meter).
3. Remote Turn-On Connection (REM):
- Connect a smaller gauge wire (e.g., 18 AWG) from the amplifier's REM terminal to the remote turn-on output of your head unit or a switched +12V source.
- This connection turns the amplifier on and off with your head unit.
4. RCA Input Connection:
- Connect RCA cables from the head unit's pre-amp outputs to the amplifier's INPUT RCA jacks.
- Ensure proper left and right channel connections.
5. Speaker Connection:
- Connect your subwoofer(s) to the amplifier's SPEAKER output terminals.
- Observe correct polarity (+ to + and - to -).
- Ensure the total impedance of your connected speakers is not below 1 Ohm, as indicated on the amplifier. Refer to your subwoofer's specifications for impedance ratings.
Operating Instructions
Once the amplifier is installed, follow these steps to configure and operate it.
Initial Setup and Gain Adjustment
- Turn the GAIN control on the amplifier to its minimum (counter-clockwise) position.
- Set your head unit's volume to about 75-80% of its maximum level.
- Play a dynamic piece of music.
- Slowly increase the GAIN control on the amplifier until you hear distortion, then back it off slightly until the sound is clear. This sets the amplifier's input sensitivity to match your head unit's output.
Filter Adjustments
- LPF (Low Pass Filter): Adjust this control to set the upper frequency limit for your subwoofer. A common starting point is 80-100Hz, but this depends on your subwoofers and other speakers in your system.
- SUBSONIC Filter: This filter removes frequencies below the audible range that can damage subwoofers and waste amplifier power. Set it slightly below your subwoofer's port tuning frequency (if ported) or around 20-30Hz for sealed enclosures.
Bass Boost Adjustment
- BASS BOOST FREQ: Select the frequency range where you want the bass boost to be most effective (e.g., 45Hz for a punchy bass).
- BASS BOOST: Use this control sparingly. Excessive bass boost can lead to distortion and potential damage to your speakers or amplifier. Adjust it to enhance bass without compromising sound quality.
Maintenance
Your Nemesis Audio NA-2.5KD amplifier requires minimal maintenance to ensure long-term performance.
- Cleaning: Periodically wipe the amplifier's exterior with a soft, dry cloth. Do not use harsh chemicals or abrasive cleaners.
- Ventilation: Ensure that the amplifier's ventilation grilles are not obstructed by debris or other objects. Proper airflow is essential for cooling.
- Connections: Occasionally check all power, ground, remote, and speaker connections to ensure they are secure and free from corrosion.
Troubleshooting
If you experience problems with your amplifier, refer to the following common issues and solutions before contacting support.
| Problem | Possible Cause | Solution |
|---|---|---|
| No power / Power LED off | Blown fuse; Loose power/ground/remote connection; Faulty wiring. | Check in-line fuse near battery; Verify all power, ground, and remote wires are securely connected and have proper voltage. |
| No sound / Protect LED on | Speaker short circuit; Overheating; Low impedance load; Faulty RCA connection. | Check speaker wiring for shorts; Ensure adequate ventilation; Verify speaker impedance is 1 Ohm or higher; Check RCA cables for secure connection. |
| Distorted sound | Gain set too high; Improper filter settings; Poor ground connection; Damaged speakers. | Reduce GAIN setting; Adjust LPF/Subsonic filters; Ensure solid ground connection; Inspect speakers for damage. |
| Engine noise (whine) | Poor ground connection; RCA cables routed near power cables; Ground loop. | Improve ground connection; Reroute RCA cables away from power wires; Install a ground loop isolator if necessary. |
Specifications
Technical specifications for the Nemesis Audio NA-2.5KD Monoblock Amplifier:
| Feature | Specification |
|---|---|
| Model | NA-2.5KD |
| RMS Power @ 4-Ohm | 445W |
| MAX Power @ 4-Ohm | 990W |
| RMS Power @ 2-Ohm | 684W |
| MAX Power @ 2-Ohm | 1368W |
| RMS Power @ 1-Ohm | 1176W |
| MAX Power @ 1-Ohm | 2500W |
| Frequency Response | 8Hz - 180Hz |
| Signal to Noise Ratio | 70dB |
| Bass Boost Level | 0-12dB |
| Bass Boost Frequency | 30 - 80Hz |
| Input Sensitivity Level | 0.2 - 5V |
| Subsonic Filter | 5 - 50Hz |
| LPF (Low Pass Filter) | 40 - 180 Hz |
| Dimensions (L x W x H) | 11.26" x 6.61" x 2.36" (28.6 cm x 16.8 cm x 6 cm) |
| Weight | Approx. 8 lbs (3.6 kg) |
| Number of Channels | 1 (Monoblock) |
| Minimum Impedance | 1 Ohm |
| Operating Voltage | 12V DC (Typical Automotive) |
| UPC | 636655223633 |
Note: The amplifier operates on a standard 12V DC automotive electrical system. The '5 Volts' mentioned in some product specifications typically refers to the maximum input signal voltage.
Warranty and Support
Nemesis Audio products are designed for reliability and performance. For warranty information, technical support, or service inquiries, please contact your authorized Nemesis Audio dealer or visit the official Nemesis Audio website. Keep your purchase receipt as proof of purchase for warranty claims.
