$2 Bluetooth Speaker technical review


The SoundLogic Suction MBSS-12 Bluetooth speaker sells individually for $5, and in bulk they can be purchased for $2. The speaker is comfortably audible at a distance of several meters, even outside, so it can be a nice inexpensive gift that is considerably better (louder, fuller fidelity) than a smartphone speaker. Battery life is a couple hours and it has micro-USB charging. It has a microphone with profiles for two-way headset as well as higher fidelity A2DP audio. The speaker plays nice with Linux as just about any device would these days (better than Windows in general).

$5 Bluetooth SoundLogic speaker

Maximum range for this SoundLogic Bluetooth speaker was 10-12 meters in outdoors, line-of-sight conditions with dozens of background Wifi APs at -80 to -70 dBm. The antenna is a meander-line with 2 dBi claimed gain. Given the +1dBm conducted transmit power, about +3 dBm EIRP for this speaker.

Remember that EIRP is just one piece of the pie when it comes to maximum range. I’ll assume the transceiver is well designed, -90 dBm or better RX sensitivity.

Why then is the range of this $2 bluetooth speaker so low? Because of antenna placement–on the $2 SoundLogic, the meander line antenna is jammed in right behind the buttons, and so the theoretical donut-shaped pattern with nulls off the longways ends of the antenna are complemented with nulls front and back of the speaker. I didn’t simulate it, but it would be some weird 3-D clover-leaf like pattern. This is why better Bluetooth speakers use dual antennas placed more optimally in their devices.