Table of Contents
BlitzWolf BW-BR4 Bluetooth transmitter
Building the perfect audio system to stream music from Spotify can be very challenging, especially if trying to design a cost-effective device. Now, this is when things get more interesting. My idea is to use a low-cost SBC (Single Board Computer) connected to the BlitzWolf BW-BR4 audio Bluetooth adapter that was kindly provided to me by Banggood for this semi review hands-on review.
Blitzwolf BW-BR4
BlitzWolf BW-BR4 | Front
Product Introduction
The BlitzWolf BW-BR4 device can function both as a receiver and transmitter device and can best be connected with external speakers. It uses Bluetooth 5.0, Lossless Transmission with an external antenna, assuring a Stable signal, long transmission distance (up to 100m), and is intelligently compatible with 99% of devices. Pure copper gold-plated terminals strengthen the stability and accuracy of audio transmission signals with Proper size and attractive appearance. t is a compact small-size case measuring 85.2 x 80.8 x 23.1mm.
It supports multiple input interfaces (3.5mm AUX, SPDIF Input/Output, CA). The Micro USB port on the rear side charges the unit’s internal 3.7V 600mAh battery via a standard 5V power adapter, making it very portable and easy to use inside a car. As mentioned previously, the device can operate in TX/RX (Transmitter / Receiver) modes with a button switch on the device’s backside.
Package
- BW BR4 Music Receiver Pkg 1
Package Content (Unboxing)
From left to right:
- 1x BR4 Bluetooth Transmitter & Receiver
- 1x User Manual
- 1x Service Contact Card
- 1x Fiber Optic Cable(100cm)
- 1x 3.5mm Audio Cable(60cm)
- 1x Micro USB Charging Cable(85cm)
- 1x 3.5mm to RCA Cable(26cm)
BlitzWolf BW-BR4 Unboxing - 1 of 9
Build Quality & Design
BW-BR4 comes in an elegant case with an excellent clean design made from high-quality plastic. It consists of a grey metallic-like surface with a very glossy upper cover in black color that can leave finger smudges.
BlitzWolf BW-BR4 - 1 of 11
Operation Modes
The BW-BR4 has a TX/RX switch on the device’s rear side. It allows you to select from Transmit/TX mode (for sending audio from a wired jack to your headphones) to Receive/RX mode (for sending music or directions wirelessly from your iPhone to a car’s AUX IN or to the AUX IN of a non-Bluetooth speaker).
Receiver mode (RX)
In receiver mode, when the BW-BR4 unit is hooked to external speakers, it can receive a stream from a portable mobile device, for example, from a smartphone or tablet PC.
Because the unit is rechargeable with an internal 600mAh battery, you can also use it inside a car. Pair your car’s Bluetooth system with the BW-BR4 and stream music to external speakers.
Transmite mode (RX)
In transmitter mode, you can connect the BW-BR4 unit to any audio source and stream the audio directly to a Bluetooth appliance. This function is handy if you have a home audio system and need wireless connectivity to stream and listen to music via headphones. Connecting to Bluetooth speakers is also a good option; if you have a pair, you can position them in a few spots inside a room and enjoy an excellent surround effect without using cables.
BC8675 Bluetooth Chip
The BC8675 chip gives you Bluetooth V5.0 and optical audio output for a universal wireless solution.
Stable Transmission
164ft Wireless Connection Range
Built-in antenna, up to 50 meters (164ft) long-range, and stable transmission to share your audio from indoors to outdoors.
Optical Fiber Transmit
It gives you the option of a digital connection to your playback device for maximum audio quality.
Long Standby Time
With a built-in 600mAh battery, you get up to 17 hours of working time and 175 hours of standby time.
Double simultaneous connections
The BlitzWolf BW-BR4 device is capable of double connection. This means that two devices can be connected simultaneously via Bluetooth connection. This can be used, for example, watching television via two headphones to keep things quiet, for example, sleeping children, or connecting two Bluetooth speakers to have music from different sources in the house from the same start.
Specification
| Brand | BlitzWolf® |
| Model | BW-BR4 |
| Color | Black |
| Bluetooth Version | V5.0 |
| Frequency | 2.402~2.480GHz |
| Interface | Micro USB(5V Charging), 3.5mm AUX, SPDIF Input/Output, RCA |
| Chipset Solution | CSR BC8675 |
| Operation Range | Class I, 100 meters |
| Bluetooth Profile | A2DP, AVRCP |
| Audio coding | TX: aptX™ HD, aptX™ low latency, aptX™, SBC RX: aptX™ HD, aptX™ low latency, aptX™, AAC, SBC |
| Battery Capacity | 3.7V 600mAh |
| Charging Time | About 2.5 hours |
| Standby Time | RX mode: About 175 hours |
| Working Time | AUX – About 15 hours SPDIF – About 17 hours |
| Operating Temperature | -10—55℃ |
| Net Weight | 111.2g |
| Size | 85.2 x 80.8 x 23.1mm |
User Case #1: Transmitting audio to car speakers
According to the power requirement printed on the bottom of the unit, to charge the BW-BR4 unit, you will need to use a 5V 0.5A power adapter (not included in the package). To avoid any future problems damaging the device, if you don’t have a 0.5A in reach, we advise sticking with a maximum 1A adapter with a standard Micro USB plug.
If you need to charge the unit, you would probably need to use the car USB socket. If you don’t have one, you can use a charger connected to the car cigarette lighter socket.
User Case #2: Transmitting audio to Bluetooth speaker
In this configuration, you can use the BW-BR4 to input audio from a source appliance, such as a home media center, and pair it with Bluetooth headphones to listen to music.
User Case #3: Transmitting audio from an SBC
Building a home Audio system
The Project Objective is to build a super low-cost audio system composed of the BlitzWolf BW-BR4 and a cheap SBC (Single board computer) running android or any Debian-based distribution.
The needed accessories/items required for this project to work listed in the following table:
Item No' | Item | Item Photo | QTY | Buy Links |
1 | BlitzWolf BW BR4 |  | 1 | |
2 | NanoPi K1 Plus |  | 1 | |
3 | A2-A2 Ribbon Flat HDMI Cable. L=15CM |  | 1 | |
4 | 5 inch 800*480 TFT LCD Display |  | 1 |
Please note that you can choose almost any SBC with an AUX or HDMI interface. If you don’t need the comfort of using a display, you can reduce additional costs from the system’s overall price by buying a board without an HDMI port. For this one, we picked the FriendlyElec NanoPi K1 Plus board that has both.
Suppose you are looking for a more elegant solution with a built-in display. It would be best if you considered buying one kit with a plastic enclosure with a built-in 3.5-inch display panel that should be enough to display general functions when playing m sic. If you prefer to mount the SBC externally, you can buy a more significant five-up to 7-inch display and mount it behind a frame housing bracket.
- BlitzWolf BW-BR4 + NanoPi K1 Plus | PIC 1 of 9
Setup & configuration:
- Enabling the BlitzWolf BW-BR4 in TX mode.
- Plugging the BlitzWolf BW-BR4 into the SBC Audio jack using the coax extension stereo cable.
- Downloading nanopi-k1-plus_eflasher_friendlycore-xxxx image.
- Burning image file to eMMC or Micro SD Card using the ‘Etcher‘ Tool.
- Installing Xfce Desktop environment: apt update & apt install xfce4
- Running Xfce: startx
- Set the output through the headphone jack interface by editing the configuration file:
sudo nano /etc/asound.conf
Changing the card interface to ‘Card 1‘ (Audio jack).
1 2 3 4 5 6 7 8 9 10 | pcm.!default { type hw card 1 device 0 } ctl.!default { type hw card 1 } |
Installing Spotify for Linux & Radio Tray
1 | sudo apt update && sudo apt install spotify-client radiotray |
That’s It! Now you are ready to pair your Bluetooth speaker/headphone with the BW-BR4 device and listen to your favorite music.
Optional Configurations (Source: AliExpress)
Configuration#1: (Raspberry Pi Board not included)
| Item Description | QTY | Buy Link |
| 7-inch Display | 1 | https://ali.ski/UjSN-D |
| Display Housing Bracket | 1 | https://ali.ski/1DgiU |
Configuration#2: (Raspberry Pi Board not included)
| Item Description | QTY | Buy Link |
| Full Kit (Case + 3.5 inches TFT Display) | 1 | https://ali.ski/jrwJ3M |
User Case #4: Transmitting audio from a Smartphone (RX)
The most popular option is probably streaming audio via smartphone from streaming services such as YouTube, Spotify, Deezer, live radio stations, etc.
To connect your speakers, you will need to use the RCA Extension cable or a stereo headphone plug to connect to the AUX port. We use a pair of old/used speakers with an impedance of 6 ohms (each) for this configure ion. Remember that this arrangement worked well, but if you need a higher volume boost, connecting the BlitzWolf BW-BR4 to a suitable hi-fi system equipped with an amplifier is best.
Results
In my test, the volume level is not very high when pairing a Huawei P20 smartphone to a pair of 6 ohms speakers (each) without an amplifier. To overcome this problem and override manufacturer default volume levels presets in your phone, I highly recommend installing a volume boost app such as ‘Volume Booster Pro.’
Streaming audio from a mobile phone to a pair of wired speakers.
BlitzWolf BW-BR4 | Streaming to wired speakers - 1 of 9
Sound Quality
From my general impression, the BlitzWolf BW-BR4 provided excellent clear s und. The AUX port is also very comfortable if you want to connect with a 3.5 mm headphone plug. If you seek maximum sound quality at higher volume levels, I recommend connecting your BW-BR4 through a coaxial or optical cable directly into an amplifier.
Range
In my test, the BlitzWolf BW-BR4 device performed well with no interference when placed in a nearby room with open doors at a distance of about 4 meters.
Charging Time
To power the BW-BR4 device, you can connect it to a standard USB port of a PC television or a car.
Battery Operation/Life
The battery life of the BlitzWolf BW-BR4 was impressive. For such a small device with a 600mAh battery inside, it can last up to 175 hours on standby mode. In real-world situations, you can expect it to work in both RX/TX modes through AUX and SPDIF interfaces for about 15-17 hours.
Price and Availablity
- Build Quality
- Internal Battery
- Sound Quality
- None
