【24H Ship】3.7V Car Subwoofer High Power HiFi Bass Bluetooth Amplifier Board

✅15W Economy version (Only Use 3.7V battery or DC 5V )​Supports reading MP3 music from USB drives and TF cards.Built-in Bluetooth receiver function, capable of receiving Bluetooth music from mobile phones.Supports FM radio mode.Can be powered by a 3.7V battery or a DC 5V/1-2A charger.Features an AUX IN external audio input for connecting to computers or car audio systems.Panel includes a wired microphone jack for singing or instrumental use.Equipped with a digital power amplifier, rated power 15W ✅D900 Supports optical audio input for broader compatibility.Specifications:​Product Name: 2.1 Channel Bluetooth Amplifier BoardModel: D900Bluetooth Version: 5.0 (10-meter range, unobstructed)Input Sensitivity: 500mVInput Modes: Bluetooth + AUX + Microphone / FM + USB + TF CardNumber of Channels: 2.1Amplifier Chip: Original imported chip (USA)Power Supply Requirement: DC 12~24V / 5A or higher (Higher voltage = higher output power)Compatible Speakers: 20~100W, 4~8 OhmsOutput Power: Left/Right Channels ≤ 50W each, Subwoofer ≤ 100WProtection Mechanisms: Over-voltage protection, under-voltage protection, over-temperature protection, AC/DC detection, short-circuit protectionHeat Sink Dimensions: 50 × 25 × 10 mm✅D800 Supports optical audio input for broader compatibility.Power Supply: DC 12~19V / 5A or higher (higher voltage provides greater output power)Input Sensitivity: 500mVBluetooth Version: 5.0 (effective range of 10 meters without obstacles)Input Methods: Bluetooth + AUX + Microphone + FM + USB + TF CardAudio Channels: 2.1-channelAmplifier Chip: Domestic amplifier ICCompatible Speakers: 20~100W, 4~8ΩOutput Power: Left/Right Channel ≤ 50W each; Subwoofer ≤ 100WProtection Mechanisms: Over-voltage, under-voltage, over-temperature, AC/DC detection, and short-circuit protectionHeat Sink Dimensions: 50 × 25 × 10 mmProduct Dimensions: 260 × 85 × 75 mm✅D50 Supports optical audio input for broader compatibility.✅D50 Amplifier PerformanceDigital amplifier with 900W peak power, drives 4Ω–8Ω impedance, 100W electromagnetic speakers.Compatible with 5–12 inch speakers. ✅D30 Description:Features:1. Support reading MP3 songs in TF card and U disk;2. Support independent adjustment of treble, bass and master volume;3, Working Voltage : AC 220V or DC 12~24V4, With AUX Audio input, can be connected to the computer, mobile phone or CD5, Digital power amplifier,can drive 4Ohm 50W magnetic speakers;6, Dual microphone input, adjustable reverb; built-in Bluetooth wireless Receiver and FM radio . Note:The above power-on methods can be connected in any way, and cannot be accessed at the same time.(4)Wiring instructions:1. Connect the subwoofer: connect a speaker with about 100 magnets or a speaker with about 100W:2, Connected to the tweeter: can be connected to 30W tweeter (It can also be disconnected) （Add a capacitor when the tweeter is connected）3.D30 Suitable for 8-12 inch speakers.Notice:Please turn off the small master volume before power-on test. Then increase the volume slowly after power-on. If the sound is intermittent or the sound is hoarse and distorted during the process of increasing the vol ✅Package Included:1Digital Bluetooth Stereo Amplifier Board1Remote control1* speaker cable1Audio Cable1US Power supply cable Smart Bluetooth Amplifier Board: User Guide & FAQGetting the Best Sound from Your AmplifierFollow these three key steps to ensure optimal performance and avoid common issues.1. Power Supply (The Most Important Step!)The right power supply is crucial. Using a weak or poor-quality adapter is the leading cause of problems like humming, distortion, or sudden shutdowns.Our Recommendation:​ For the best performance with most speakers, use a stable 18V-24V power adapter with at least 8A current.Why?​ Higher voltage provides greater output power and cleaner sound. A power supply with insufficient current will cause the amplifier to cut out at high volume.2. Speaker CompatibilityMatching your speakers correctly is essential for sound quality and safety.Left/Right Channels:​ Use 4-8 ohm full-range speakers. The ideal power handling is between 30W and 200W.Subwoofer Output:​ This port is only for a dedicated subwoofer. Do not connect regular speakers to it. The recommended subwoofer power is 50W-200W.3. Adjustment & TroubleshootingHow to Adjust the Sound?MAIN-VOLUME:​ Controls the overall volume level.R&L CHANNEL BASS/TREBLE:​ Adjusts the low and high frequencies for the main speakers. Turning the knob to the middle is the neutral setting.SUBWOOFER VOLUME/FREQ:​ Controls the subwoofer's loudness and the pitch of the bass (frequency range: 20Hz-200Hz).Troubleshooting Common Problems:Problem: Humming or buzzing sound. Solution:​ This is almost always caused by electrical "ripple" from a low-quality power supply. Replace the power adapter​ with a high-quality one.Problem: Sound distorts or cuts out at high volume. Solution 1: Your power supply is too weak.​ Use a more powerful adapter (e.g., 24V/8A). Solution 2: You are overloading the amplifier.​ Do not set both the TREBLE and MAIN-VOLUME to maximum at the same time,​ as this can trigger the amplifier's protection circuit. Reduce the volume or treble.Problem: How to switch between Bluetooth, AUX, and USB? Answer:​ The input priority is automatic: USB > AUX > Bluetooth. If a USB drive or AUX cable is plugged in, it will take over. You can also manually switch between active inputs using the selector knob.By following this guide, you can ensure your amplifier delivers clear, powerful, and reliable sound.