E5 Portable Bluetooth Sound System (+ hidden feature)

The E5 portable bluetooth speaker from lightinthebox.com is an IPX4 waterproof stereo BT 4.2 speaker with speakerphone function for €33.73 

Specifications:

Waterproof: IPX4 (Protects from splashing water, no matter the direction)

Bluetooth connection: Bluetooth 4.2

Input voltage: DC5V/600MA

Output power: 5W THD+N≤10%(1KHz/0dB)

Battery: 3.7V/2000mAh

Speaker unit: Φ40mm, 4Ω/5W

Frequency response: 200Hz-20KHz

SNR (signal to noise ratio): ≥84DB

Working time: 3~6 hours

Receiving frequency range: 10 meters (verified)

Speaker Size: 23x12x9cm

Speaker Weight: 859gr (verified)

Package content:

1 x Bluetooth Speaker

1 x USB charging cable
1 x 3.5mm Stereo jack cable

1 x User manual (English)

Functions, Sound, Range and Battery 
The E5 can play music from any Bluetooth source, USB drive, stereo jack input  or directly from its integrated micro SD card reader. All connectors are hidden behind rubber flaps to ensure the waterproof protection.

While the most convenient way for playback is the Bluetooth method, providing a stable connection with the sound source within 10 meters, the sound quality is obviously better via jack connection, USB source, or memory card. For these 2 last modes, I regret the absence of a random play mode.
The source is changed by pressing the M (mode) button.

There's a faint humming noise from the speaker in Bluetooth mode but this is only noticeable when the unit is silent.
The sound is rich with great basses and the volume can be set very loud without degrading the quality.
The initial volume level when powering up the speaker tends to be quite high and a memory of the previously set level would have been nice.

The speaker will appear as "E5" when pairing and will double as a speakerphone. In this mode, the sound is very average but should do the job for occasional use.

The 2000mAh battery provides between 3 to 6 hours of playback, depending on the volume and source used. Since it is recharged via its USB connector, the play time could be easily extended with a power bank.

IPX4 rating

It is worth mentioning that the unit is reasonably well protected from water with its IPX4 rating (splash resistant).

Undocumented feature: FM RADIO mode

One of the available modes via the M button is the FM Radio.
An audio cable must plugged into AUX to act as an antenna.
Scanning frequencies is done with the Previous and Next Track buttons.
It's extremely basic without stations memories, frequency display or RDS but it's still a good feature to have.

Here a short overview in video:

The E5 Portable Bluetooth Speaker Sound System is a nice-looking wireless boom box with good sound quality that could even withstand an Irish summer (IPX4 rating).

It is sold by lightinthebox.com for €33.73

Pros
USB and microSD
FM Radio (needs cable connected to AUX)
Good BT range
Good 🔋 life
Basic FM radio function

Cons
Very loud startup volume (no memory of previous volume level)
Slight humming noise in BT mode
No random playback  mode