The principle of adding Bluetooth function to wired speakers is very simple, nothing more than adding a Bluetooth receiver to the chassis to enable it to receive Bluetooth signals.
There are two methods for specific operation, one is to disassemble the box and install the Bluetooth receiver inside the box to achieve the perfect unity of function and appearance.
The second method is to connect the Bluetooth receiver directly outside the speaker. The advantage is that the operation is extremely simple and almost does not require any hands-on ability. The disadvantage is that the audio and power cable will be exposed, and the appearance level is inferior.
The following is a detailed introduction to the transformation process.
Prepare tools
1. A screwdriver
Here again recommend personal favorite most commonly used tools, South flag S2 screwdriver set, knife head many, very convenient and easy to use.
2. One Bluetooth receiver module
There are two cheaper Bluetooth receivers that can be found:
One price is relatively cheap, there is no 3.5mm audio input interface, only a 3.5mm audio output terminal, can only accept the Bluetooth signal, and then output audio.
After using this Bluetooth receiving module, it is impossible to input a wired audio signal, and the speaker will become a pure Bluetooth speaker.
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The price of this Bluetooth receiving module is a little more expensive, about 30 yuan or more. I chose this because I didn't want to give up the wired transmission function completely.
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The properties of this Bluetooth receiver board are as follows:
Input voltage: DC5V-12V
Bluetooth version: 4.2
Bluetooth name: LQSC_BT
Peripheral size: 55*32*9(length * width * height)(mm), can be used in combination
Full patch process
Wide range of operating voltages
The power supply is connected to reverse protection
Dual AUX input terminals (3.5mm and 2.54mm 3P)
Dual audio output terminals (3.5mm and 2.54mm 3P)
External antenna (suitable for installation in metal box)
LED indicator description
Quick blinking: Waiting for a connection
Blinking slowly: The audio is playing
Steady on: The device is connected
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3.3.5mm male to male audio cable
It is used to connect between speakers and Bluetooth audio boards, and if the requirements are not high, Jingdong can buy a cheap one. I bought this is green link 0.5m line, measured normal use.
4. One microUSB data cable and one idle phone charger
This Bluetooth receiving board directly with the USB interface of the computer motherboard power supply, there will be a noise phenomenon, personal suspicion is AUX input interface and motherboard USB power supply caused by common ground interference caused by noise - due to non-professionals, the specific reasons do not understand. According to the suggestions of netizens, the Bluetooth board uses a 5V1A mobile phone charger for independent power supply, which perfectly solves the problem.
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microUSB is one of these older connectors, common on phones from a few years ago.
5. Hot glue gun
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If you want to make better use of the Bluetooth receiver board, it is best to fix it in the speaker housing or elsewhere to prevent loss or damage caused by cable pulling. Here I use less than 10 yuan to buy a small hot glue gun, the price is cheap, very useful.
Bluetooth receiver out of the box
In order to prevent damage to the components on the exposed circuit board, an acrylic shell was also purchased. The packaging content is very simple, a bag of acrylic sheet, a bag of copper post screws, a publicity card, and Bluetooth receiver board, data cable, manual.
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Bluetooth receiver body, looks quite delicate.
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The instructions are simple, but you've got most of the information you need.
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There are also audio cables with rectangular connectors, which are not available this time.
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The structure of the acrylic sheet is also very simple, these pieces, in the base and the top cover are reserved for the slot used to fix the side plate.
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operational process
1. We assemble the acrylic shell first
First fasten the shorter copper column to the base piece with screws.
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Place the circuit board on the short copper column.
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Note that both sides of the acrylic sheet are covered with plastic film, it is best to tear off before installation, so that the side plate can be inserted into the slot of the base and the top cover.
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Insert the side panels into the slots on the base.
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Finally, cover the top and screw into the long copper column to fix it.
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2. Connect the input and output audio cables and the microUSB power cable
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According to the instructions on the circuit board, connect one end of the speaker's long 3.5mm male-to-male audio cable to the computer sound card output and the other end to the Bluetooth board AUX input.
Connect one end of the 0.5m-long 3.5mm male to male audio cable purchased separately to the 3.5mm output end of the Bluetooth board and one end to the wire control of the speaker.
Finally, plug in the charging cable to the microUSB interface of the Bluetooth board, and connect the phone charger for power supply.
3. Attach the acrylic shell to the chassis shell using a hot melt glue gun.
Because the base will have exposed nuts, so the hot melt glue to apply a little more, a little thicker. Here I chose to stick the acrylic box to the back of the speaker, so that it is not easy to find, and the impact on the appearance level is small.
measure of merit
1. First of all, use NetEase Cloud Music on the computer side to play songs. At this time, the playback method is wired through the audio cable, and the music can be played normally.
2. Then use the Huawei P30 to play a piece of music, and enable the Bluetooth function at the same time, you can find the Bluetooth device as shown in the picture:
After connecting the device, you can find that the music second played in the speaker is changed to a song on the mobile phone.
Turn off the phone's Bluetooth function switch, and the speaker switches to the computer to play music in seconds, with almost no pause in between.
4. With the iphone6s test, the results are the same, and the Bluetooth playback function can be successfully realized.
5, about the sound quality, because they are wooden ears, and the sound quality of the speaker they use is ordinary, when using Bluetooth to play music, compared with the original wired connection of the speaker, basically no difference can be heard.
6. Desktop 2.1 speakers used by ordinary users are mostly similar to the 10th anniversary of the M200, which is an active speaker. This speaker has a built-in power amplifier circuit, so when using a Bluetooth receiver board with this type of active speaker, there is no need to buy a separate power amplifier circuit board.
Active speaker refers to a type of speaker equipped with a self-matching power amplifier inside the speaker. These amplifiers are specially used to push the speaker in the speaker, because of the special matching design, so these amplifiers can be better used to push the speaker in the speaker, so that the user does not need to consider the power of the amplifier and whether the impedance matches and other issues. In addition, because the speaker is also equipped with an electronic frequency divider in the front of the amplifier for frequency division, and each amplifier is only responsible for amplifying a frequency of the audio signal, the efficiency of the amplifier can often be higher, and the distortion can be relatively small.
At the same time, I used this circuit board to push the AKG450 headset, and the test can push, no problem.
If you want to use passive speakers and high-power headphones, etc., you can separately match a power amplifier circuit board of more than ten dollars, and the store also sells it. However, according to the suggestions of netizens on the product page, if you use Bluetooth receiver and amplifier board at the same time, it is best to use two different chargers for power supply to avoid common ground interference.
summarize
Using the Bluetooth audio receiver module can be extremely easy to change the wired speaker into a Bluetooth speaker, basically do not need any hands-on ability, just connect the wire, plug and play super simple.
The board used this time outputs analog audio signals, which is suitable for the ordinary sound quality speakers of most users. At the same time, it is recommended to use 5V mobile phone charger or charging bank for power supply, and it is easy to generate bottom noise when using the USB interface of the motherboard for power supply.
For big guys with high sound quality requirements and strong hands-on ability, you can search boards such as CSR8630.
Ordinary desktop 2.1 speakers are mostly active speakers, so there is no need to buy a separate power amplifier board.
This is very simple, buy a Bluetooth receiver that can output audio signals, connect the audio output of the Bluetooth receiver to the audio input of the speaker, and the wired speaker becomes a Bluetooth speaker.