300W 2.1 Channel Speaker Protection Board – Relay Module
300W 2.1 Channel Speaker Protection Board – Relay Module
300W 2.1 Channel Digital Amplifier Speaker Protection Board
Keep your audio system running cleanly and safely with this 300W 2.1 Channel Relay Speaker Protection Board. Designed for DIY audio builders, home theater enthusiasts, and electronics hobbyists, this board provides delay startup and DC offset protection to guard your speakers from potentially damaging signals. Made in Mainland China.
Key Features
- Delay & DC Protection: Built-in startup delay and DC offset detection (default 1.8V control, adjustable DC sensitivity) prevent unwanted transients from reaching your speakers.
- Optocoupler Isolation: Uses an optocoupler for input/output isolation, providing excellent electrical insulation and strong anti-interference capability with unidirectional signal transmission.
- Common Mode Suppression: The low-resistance current-type input of the optocoupler delivers superior common mode rejection for a cleaner audio signal path.
- Three Independent Channels: Each of the 2.1 audio channels (Left, Right, Subwoofer) is independently managed — suitable for non-common ground and BTL circuit amplifiers.
- Power & Audio Source Separation: Power and audio source are kept separate so the sound source signal remains unaffected by power fluctuations.
- High-Quality Relay Core: Songle relay as the core component ensures lossless audio transmission and resists contact oxidation and sparking.
- Heavy-Duty PCB Construction: Built on a 1.6mm thick 1A copper surface PCB with double-sided tin plating for reliable, long-term performance.
- High-Current Design: 7.62 pitch terminal blocks with 1/2W metal film resistors and reduced internal resistance, optimized for high-current applications.
- Power Indicator LED: Red power-on indicator light confirms normal operation; relay auto-adjusts engagement timing on startup surge.
Specifications
- Voltage Input: DC 12–16V or AC 12–16V
- Channel Design: 3 independent channels (2.1)
- Max Supported Power: Up to 300W × 3 channels
- PCB Size: 97 × 51 × 17 mm
- Terminal Pitch: 7.62mm
- DC Protection Threshold: Default 1.8V (adjustable)
What's in the Box
- 1 × 300W 2.1 Channel Speaker Protection Board
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Frequently Asked Questions
Q: What does the 300W 2.1 channel speaker protection board do?
A: This speaker protection board shields your connected speakers from DC offset voltages and startup/shutdown transients using a relay-based circuit with optocoupler isolation. It supports three independent channels (left, right, and subwoofer) with up to 300W per channel, making it ideal for 2.1 amplifier builds.
Q: What power supply does this protection board require?
A: The board accepts either DC 12–16V or AC 12–16V input, making it compatible with most standard amplifier power supplies. The power supply can be shared with the main power amplifier circuit.
Q: Is this protection board compatible with BTL amplifiers?
A: Yes. Because each of the three audio channels is fully independent (non-common ground design), this board is well suited for use with both standard and BTL (Bridge-Tied Load) amplifier configurations.
Q: Can I adjust the DC protection sensitivity?
A: Yes. The DC detection threshold defaults to 1.8V but is adjustable, allowing you to fine-tune the board's sensitivity to suit your specific amplifier setup and components.
Production & Packaging Notice
To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.