Description:1. Adopting high-power digital power amplifier dedicated inductors, high current, low magnetic loss, low heat generation, and using oxygen free copper wires to improve sound quality; The magnetic shielding mechanism is resistant to electromagnetic interference.2. QCC3034 module, supporting transmission encoding SBC, AAC, APTXAPTX-LLAPTX-HD.3. QCC3034+PCM5102A, lossless transmission, lossless decoding, no loss, perfectly displaying the dynamics and details of sound, without burrs at high frequencies, rounded at mid tones, powerful at low frequencies, and good elasticity.4. Extremely high parameter performance: dynamic 112dB, signal-to-noise ratio 112dB, distortion level -93dB.5. Equipped with protection mechanism, input undervoltage, input anti reverse connection, overheating, overcurrent, and short circuit protection.Parameter:Product name: 2.1 channel BT amplifier board 100W+100W+200WProduct model: ZK-APTX1Adapted power supply: The working voltage range is 12-30VDC, and it is recommended to use a DC power supply with a voltage of 24V-28V and a current of 10A or above.Maximum power: left or right channelu2014u2014 105W@30V , 4 u03a9; 55W@30V , 8 u03a9. Subwooferu2014u2014 208W@30V 2 u03a9; 105W@30V , 4 u03a9. In short, the higher the voltage, the smaller the resistance, and the greater the output power.Adapted speakers: left and right channels, supporting speakers up to 3-8 ohms and 100W; The subwoofer supports 2-8 ohms and speakers up to 200W.BT chip: QCC3034, transmission distance of 15 meters.Input method: Bluetooth+AUX, BT priority, Bluetooth needs to be disconnected when using audio cable input.Number of channels: 2.1, left and right channels+subwooferPower amplifier chip: Two TPA3221Protection mechanism: Input undervoltage, input anti reverse connection, overheating, overcurrent, short circuit protection.Product size: 118x100x25mmInstalling an external antenna (special scenario):1. The boards are equipped with onboard antennas, with a normal distance of 10-15 meters. If they are installed in a metal shell (which will block the signal) or increase the Bluetooth distance (20-30 meters), external antennas will be used.2. Customers are required to purchase 2.4G antennas (antenna extension cables, antenna rods) on their own, and this product does not include external antennas.Package includes:Set 1:1 x APTX1 amplifier boardSet 2:1 x APTX1 amplifier board1 x ShellSet 3:1 x APTX1 amplifier board5 x Lead wire

Question and answer:What kind of speaker does it come with? How much power is used? Recommend an amplifier?In fact, this is the same question because the three of them are related. I believe that after learning the following knowledge, no matter what kind of amplifier you make, you will calculate the compatibility relationship between the power supply, speaker, and amplifier yourself.1. According to Ohm"s law, power P=U * U/R, the higher the voltage, the smaller the horn resistance and the greater the power; So the final output power is not only related to the power amplifier, but also to the power supply voltage and the resistance of the speaker. According to the formula, if the power supply is 24V and the horn resistance is 4 ohms, then the peak power=24V * 24V/4 u03a9=144W, and the effective value (rated power) of a 1 kHz sine wave=24V * 0.707 * 24V * 0.707/4 u03a9=72W; The peak power of an 8-ohm horn is 24V * 24V/8 u03a9=72W, and the rated power is 24V * 0.707 * 24V * 0.707/8 u03a9=36W, If the power supply is 12V and the 8 ohm horn is used, the peak power is 12V * 12V/8 u03a9=18W, and the rated power is 12 * 0.707 * 12 * 0.707/8 u03a9=9W. Our amplifier"s nominal power is the rated power, and later on, it defaults to the rated power.2. In order to leave sufficient power margin and avoid clipping distortion, it is better to have an amplifier power of 1.5-2.5 times the speaker power. For example, if your single channel speaker is 100W, the corresponding amplifier board"s single channel output power should be between 150W and 250W. Speakers can be connected in parallel or series. Two 8-ohm and 50W speakers connected in parallel are equivalent to a 100W4 ohm speaker. It is recommended to choose an amplifier with a typical load impedance value that is the same as the final impedance value of your speaker system. This amplifier generally support 4-8 ohm speakers, while a few high-power amplifiers support 2-8 ohm speakers. If the speaker resistance is too small, the amplifier chip is prone to overcurrent power protection or burning.

3. The choice of power supply is also very important. Some one use a 5V2A mobile phone charger or a 12V1A2A adapter to drive a 50W100W amplifier, but the voltage and power are obviously not enough. Ultimately, the voltage is pulled down, and the sound becomes distorted and distorted when slightly louder, resulting in a cloudy sound or intermittent protection from the power supply causing sound lag. It doesn"t matter if the power supply is too high, but if the power supply is not sufficient, the problem mentioned above will occur. So what size of power should be chosen? This issue involves two parameters: voltage and current. In theory, the power supply should be greater than the total power of the power amplifier. For example, if TB21 is a 50W+50W+100W power amplifier, you should choose a 24V8A or higher power supply. But there is also a situation where the speaker you choose is not that large. In order to facilitate power adaptation or reduce power costs, you can calculate the actual power required. For example, the subwoofer speaker you choose is 4 ohms 50W, and two stereo speakers are 8 ohms 30W. If you choose a 12V power supply, the maximum output rated power of the subwoofer is P=12 * 0.707 * 12 * 0.707/4 u03a9=18W. Obviously, a 12V voltage cannot meet this requirement. Try a 24V power supply again. The subwoofer output P=72W, the stereo output P=36W+36W, and the total power is 144W. Therefore, a 24V6A power supply is sufficient. Some one say that I have a 24V20A power supply with a power of 480W, but it"s better to have an 8-ohm 100W speaker. According to Ohm"s law, a maximum power output of 36W can be achieved with a 24V and 8-ohm power supply. Obviously, the speaker cannot be pushed. Although the speaker has sound, it is not full enough. According to the formula, the voltage needs to reach 40V or above. Another thing to note is that the power supply of adapters on the market is falsely labeled, and 24V8A10A adapters may be protected for less than 6A.

4. Many customers have a misunderstanding: the higher the power of the amplifier board, the louder the speaker must be. The answer is uncertain!Real case 3002T (300W+300W) power amplifier. I suspect that this amplifier has a serious false label. The sound is not as loud as other 30W amplifiers, and it is not 300W at all. In comparison, the normal power amplifier gain is 36dB, the speaker is 8 ohms 30W, and the power supply is 24V. According to the formula, the maximum mono output power is 36W; when using the 3002T, the power supply is also 24V, and the speaker is 8 ohms, 150W. However, according to the formula calculation, the maximum output is also 36W, and the gain of 3002T itself is 32dB. The original volume of the small power amplifier was adjusted to 70%, achieving 100% of the volume of the large power amplifier. The problem is clearly not a miscalibration of the amplifier; In this case, a 48V6A or higher power supply should be selected to make full use of its power. Obviously, a 30W small power amplifier cannot support 48V power supply and 300W output.