How to improve bluetooth connection. Is it possible to increase the Bluetooth range on Android
Review of an interesting and compact amplifier with Bluetooth on board, a wide power range and good characteristics.
Packaging and delivery.
Order processing took 2 days, delivery another 13 days.
The track was issued, full tracking, from dispatch to my post office.
The impression of the store and delivery is good.
I picked up a typical Chinese black light package from the post office; it didn’t inspire much confidence since it was quite thin. 
Having opened the package, I saw the amplifier in antistatic and 4 layers of foam, quite enough to protect small elements from damage during transportation. But if the post office tries, it might break it. 
Review
<Фото в большом разрешении, советую кликнуть и рассмотреть поближе интересующие элементы.>
Back view
There is nothing remarkable here, except perhaps holes for heat removal from the chip to the bottom printed circuit board where is the large landfill. 
Chicane
There is flux snot on the contacts, it does not affect the operation, but it is clear that the board was not washed after soldering the connector. 
Board Dimensions
The board is 5cm wide 
Length 8cm 
And 1cm thick
Ts 50x80x10mm
18650 for comparison 
Type of connectors
The connectors for connecting the speakers are very convenient, their design is made so that they do not squeeze out the wires (unlike cheap terminal blocks). The size is sufficient to connect fairly thick and tinned wires.
Power connector
The power connector is universal or made with a good margin. Almost all modern laptop plugs fit into it. 
The board can be powered from 8 to 25 volts, nominally 20 volts.
When powered by 3x 18650, no problems were noticed, either with fully charged or with discharged ones, up to 2.9V each.
At the power input there is a diode against over-reversal. If you place the amplifier in finished device then the diode can be removed to avoid a voltage drop (about 0.3V).
There is no capacitor on the power line, just as there is no place for it to fit, I assume that this module is powered by batteries, where this same capacitor is not needed. 
Bluetooth module and pre amplifier
The pre-amplifier is made on the N5532 chip
I can’t say anything interesting about it, it’s an ordinary low-noise two-channel operational amplifier.
Thanks to the large power supply range, you can connect a wide range of power sources to the device, ranging from 18650 batteries (3 pcs in series) to power supplies for laptops.
The manufacturer promises 90% efficiency (which, with an output power of 50 watts, gives 5 watts of heat.)
Recommended characteristics - 2 channels of 25 watts with a speaker impedance of 8 ohms and a power supply of 20 volts.
A small clipping from the datasheet 
The microcircuit is designed to work in TVs and monitors, but nothing prevents you from using it for your own purposes - to work with a Bluetooth module.
Although the chip has a fairly large output power, it does not require active cooling; all heat goes through the substrate and is distributed throughout the board.
Even under intense loads, there is no significant heating of the board and microcircuit.
You can also see a double switch on the board; all it does is change the signal amplification mode. But I don’t see the point in it, because if you switch any of the switches to ON, noise will appear (interference from bluetooth).
The store page has an excellent description of the amplifier's controls and connections.
The purpose of the buttons is duplicated on silkscreen printing. 
Compound
Establishing a connection with Windows 10 On PC
I have a laptop Asus rog gl552vw, but the onboard module is from Intel with wifi and bluetooth 4.0
To connect the amplifier you need to go to the bluetooth parameters (click on the cloud in the panel below
then right-click on the bluetooth icon and select “go to settings”
A list of available Bluetooth devices will open.
We select our amplifier; it is highlighted by an icon in the form of headphones. 
Click connect and wait for the connection. 
After connecting, 2 new devices will appear in the volume control panel.
The sound will be terrible. 
As the default device, “headphone” is selected, click on “headphones” and click on the “default” button at the very bottom of the window. Now the sound will be of normal quality.
A little information
The headphone has a low-quality audio format and is intended only for conversations. 
The headphone mode has acceptable quality for music. 
About the Bluetooth device 
Connecting to Android
Turn on Bluetooth, go to its settings, find our amplifier in the devices section, click on it, wait for pairing. 
After pairing, you can turn the mode on and off wireless headset and a wireless media stream receiver. 
When adjusting the volume, the smartphone speaker adjustment slider changes to the Bluetooth device volume adjustment slider. 
Tests
Foreshadowing questions about video - there won’t be one; assessing sound quality using a smartphone’s microphone is, of course, stupid.
Sound quality is a solid 4. Bass cuts only at the highest volume
High frequencies are not reduced.
I also have a MASTERKIT BM2039 at home on a TD8560Q chip (I bought it a long time ago before the crisis for 150 rubles), it produces a little more bass and plays cleaner at high volume, but at the same time it heats up MUCH more and has only 12V power.
Conclusion
The impression of the product is purely positive, the problem with power supply is very easily solved by purchasing a regular power supply for laptops; a standard 19V 4.7A power supply will not even heat up during operation.
Good characteristics allow you to listen to music at an acceptable volume without loss of quality.
The wireless connection turned out to be very convenient, no more wires are needed, connect your smartphone, turn on the music and continue using your smartphone.
If you use it at home, you can connect 2 devices at once - a PC and a smartphone, the Bluetooth module will look where the sound comes from and play it, without manually switching the signal source.
Also, when used in a car, you can install a microphone and get a Hands free headset.
The only thing that spoils the impression is the very quiet noise from the Bluetooth module.
pros
-Wireless connection
-Large reception radius
-Wide range of supply voltages
-Compact sizes
-Quality execution
-Easy to use
-Low price
Minuses
-Small interference and noise in the speakers
-Wheezing at very high volumes
-No plastic stands as in the photo in the store
There is also the same amplifier but with an additional linear output for connecting headphones or another amplifier, the price is even slightly lower.
Wireless devices are very convenient - you no longer need to worry about wires, but you must clearly understand that over-the-air communication has its own radius limitations. Moreover, the cheaper, for example, the Bluetooth adapter that you purchase for your computer is, the less you can move away from it in order to get a stable connection. Of course, some expensive devices do not always produce good results. Today we will talk about how to strengthen the Bluetooth signal and how realistic it is.
general information
The article describes some methods that involve disassembling the adapter, replacing its parts, or modifying it by soldering, which may not be suitable for everyone. If you do not understand electronics, are not very agile in using a soldering iron, or your device is under warranty, then please avoid such methods.
Complementing the adapter
The simplest, but not the most effective method How to increase Bluetooth speed can be considered adding a reflector to the adapter, which will direct the signal in a certain direction, rather than enhance its distribution over the entire 360 degrees.
You can try to make such a reflector from a tin beer can by cutting off the top and making a few more slits: from top to bottom and then slightly to the sides, as if slightly separating the bottom of the can.
The Bluetooth adapter is attached in the center with whatever you like and connects to the computer with a USB adapter.
Something similar can be built from cardboard with foil glued to it.
Another option that may work is to cut off just the top of the can, then make a slot for the housing towards the bottom of the can and insert the adapter in with the antenna side on it. Then, again, we fix it using a method convenient for you and connect it via an extension cord.
Modifications
Now we’ll talk about methods that involve physical modification of the adapter itself. In cheaper ones you are unlikely to find an external antenna, which, in fact, is their problem.
We open the case, if possible, and look for the SMD antenna, which is soldered into the board - you will need to unsolder it, only very carefully, without overheating the part.
Next, we solder an SMA connector in place of the antenna, having first removed all unnecessary things: we do not touch the part into which the antenna is screwed, but at the other end we cut off the edge, separate the screen and wires, strip them, tin them and solder them.
If you have any doubts about where exactly to solder what, then it is best to turn to amateur radio forums.
Now we connect to what we have, an antenna that can be easily twisted from the old Wi-Fi.
If you have more expensive device already with an external antenna, but you are still unhappy with the signal, then a Hyper gain antenna can save the situation - buy it, cut off the adapter for connection and separate the screen from the core.
A Powerbeats wireless Bluetooth headset was brought in for repair with an atypical breakdown—it doesn't connect well with Bluetooth.
The owner of these headphones claims that when he holds the phone in his hands, the headphones play, but as soon as he puts the phone in his jeans pocket, the bluetooth connection disappears and the sound disappears after it.
An amazing failure, considering that Bluetooth should work reliably up to several meters. There have even been cases when the working radius of some bluetooth headphones reached up to 30 meters.
Before disassembling the headphones, the technician suggested to the owner of the headphones that the bluetooth antenna itself might be broken.
After disassembly, it became clear that in these headphones the antenna is implemented in the form of tracks on the board.
The antenna is located on both sides of the board.
This is the first time the master has seen such a design implemented.
There was an assumption that this Chinese copy Powerbeats wireless headphones. And since the Chinese sometimes do some things poorly, our master decided to strengthen the Bluetooth signal by increasing the antenna with a regular insulated wire from other headphones.
Having tested this modification, we could say that the reception radius has increased, but when compared with the original working headphones, the radius is still at least two times smaller.
There are two chips on the board:
Judging by the filling found in every second Chinese headphone, we conclude that it is a Chinese copy.
Nowadays, smartphones, telephones, or communicators with built-in Wi-Fi adapter. And the range of Wi-Fi is about one hundred meters, but phones that are equipped with Bluetooth transmit and receive files only at a distance of no more than ten meters. If you have USB-blutooth for your computer, as well as a phone with bluetooth, but you would like to increase the reception range. All this is quite possible, but usb-bluetooth needs to be improved.
Well, let's begin. We disassemble the bluetooth adapter for the computer, after that you need to debug the bluetooth case and very carefully inspect the adapter board.
In all adapter models, at the end of the board there is a copper contact that looks like a spiral, in the photo it is number 1. This spiral is a bluetooth antenna, and it is to it that an additional homemade antenna will be soldered.
We will need a single-core copper wire with a diameter of 0.4 to 0.8 mm. The wire is covered with varnish insulation, and there is no need to get rid of it completely. Let's twist the wire as shown in the photo, then treat the tip of the copper wire with rosin, then with tin. The same procedure must be carried out with a copper spiral in Bluetooth, do not overheat the adapter board, do all the work very carefully.
Then, you need to make a hole in the body itself for bluetooth adapter, at the exit point homemade antenna. Now let's very carefully close the board in the case. Now the upgraded bluetooth is ready, which increases the reception range by 4 times.
To further increase the reception range, you can take a stranded wire that is long enough, which will be covered with insulation, you need to strip the tip and attach it to the antenna, the second tip can be attached to a small nail driven into the wall.
In this article we’ll talk a little about the Bluetooth range on Android. Some users may not be satisfied with the range of their Bluetooth module: For example, in the house, when the phone is three walls away from you, your headset loses connection with your smartphone. Many in such cases are looking for a solution to this problem, trying to find a way to increase the Bluetooth range on Android. We will talk about this in more detail in this article.
A little theory
The receiver itself operates in the frequency range of 2.4 – 2.48 GHz. It works like a regular radio communication, in which the data exchange speed, depending on the version of the receiver, can reach up to 721 Kb/s (in version 1.1), up to 24 Mb/s (in version 3.0 - 4.0).
As for the distance at which information exchange can occur, it can reach 50 meters, provided that the devices are in line of sight from each other, and about 10-20 meters in buildings.
Although the manufacturer claims that with version 3.0 of the module the range can be 100 m, this is most likely in ideal conditions: in fact, the coverage in these versions is at least 2 times less, that is, about 50 meters, again in line of sight zone.
As for amplifying frequencies on the smartphone module, this option will not always solve the problem, since communication between devices depends on both modules. To make it clearer: even if you manage to expand the range on your phone, the radius of successful operation with your headset will remain the same, due to the fact that the headset will be able to find the smartphone at the same frequency as before.
Yes, the phone will be able to detect the headset at a greater distance than before, and you may even be able to pair both devices, but the distance at which such a pairing will work successfully will not increase. Perhaps your voice from the microphone will reach the phone, but you will not be able to hear the interlocutor, or vice versa.
The result is the following combination: the phone can download data from the headset, but the headset will not have enough range of its module.
Therefore, if you want to increase the operating radius, you will have to work with two devices.
What will it take?
Theoretically, to strengthen the bluetooth, similar to overclocking the processor, you just need to apply more voltage to the module: we expect that there should be some kind of program, for example, a Bluetooth range extender for Android, that would work with ROOT rights and did everything in a couple of clicks... but, sadly, there is nothing like it anywhere.
The situation is the same as with firmware: each device has its own firmware, and there is no universal firmware for everyone. This is because the OS settings contain individual parameters for the components, and those are the ones on which the components of your smartphone will work correctly.
Alternatively, you can extend the range by adding an antenna. If this approach can still be assumed on a stationary PC, because there is physical space there where you can add this antenna, in a situation with a smartphone this method just inappropriate.
The last method, which, in our opinion, is the most successful, is to purchase a special flash card with a built-in Bluetooth receiver function. Such cards are similar in appearance and size to a regular SD card, have different formats, and also have a communication module added to them (they also exist with Wi-Fi).
Initially, such cards were released for devices that do not have a built-in module, but in your case we advise you to try inserting them: perhaps the Bluetooth in the card will be more sensitive than the one built into your device; there is still a possibility that the card module will have more new version, thanks to which the range will be greater than that of the built-in module installed in your phone.
