The Sound2 speaker has built-in magnets, so it can easily cling to any metal surface, like refrigerators or metallic furnishings.
Available in red or grey, the square speaker has a minimal design and is just 95 millimetres by 95 millimetres in size.
"Sound2 Bluetooth Speaker is a great example of 11+'s minimalist and sensible design philosophy," said the designers.
"Its low profile and boxy design allows it to be carried and stowed with ease, and it's equipped with magnets for mounting versatility," they added.
The speaker connects to music-storage and streaming devices via Bluetooth, and is powered by a rechargeable battery. Three hours of charging via the supplied cable provides 10 hours of battery life.
11+ and Cloudandco both focus on applying minimal design principles to an array of products. The two studios have previously worked together on a house-shaped scent diffuser and a bottle-like desktop humidifer.
11+'s other past work includes a portable humidifier with a transparent bottle, monochrome packaging and a red USB charging cable.
Other speakers on Dezeen include a portable device by industrial designer Michael Young and Italian electronics company Brionvega that can be worn like a satchel and a set originally created by architect Jean Nouvel for his controversial Philharmonie de Paris.