Great mobile loudspeakers at a reasonable price

I have these speakers gained for an extended business trip to be able to comfortably listen to music in the hotel rooms.
Mainly I use the Bluetooth connection to transfer music and am both Übertragungsqaulität, and reach
more than satisfied.
Connections via 3.5mm blade I have tested on a television and even here there were no problems.
The playback of a micro SD card I have not tested, but is also rather irrelevant to me.

The sound of the speaker has fully met my expectations at this price.
Treble and midrange sound good, the centers suffer something as soon as you no longer located in the direct "radiation field" of the speaker.
The depths are perfectly adequate, depending on the sound even impressive for the size of the device.

The battery life I have not measured, but I would be regarded as realistic given the 12 hours.

The volume I find more than sufficient, it must be said that at maximum volume the sound quality suffers. However, this volume, I feel too loud and not suitable for 95% of the situation.
The only thing that really bothers me is the extremely loud Start-up. Each time you turn the speakers are a melody of itself that has no obvious added value for me and often uncomfortably loud compared to the following music.

With a higher-priced device such as a Mini SoundLink from Bose, these speakers can not keep up with, but for a price around 50 I can only recommend this speaker.