Best bike Bluetooth speaker for 2025 - CNET Size Defying Sound: Upgraded StormBox Micro 2 delivers explosive outdoor-audio more than any other speaker in its class. Specially designed 48mm NdFeB driver and integration of passive radiators plus exclusive XBASS technology reproduces a dynamic sound with an incredible bass range. RunStretch Technology: This pocket-sized Bluetooth speaker come with a high-capacity rechargeable battery makes it a perfect outdoor companion for a full day activities. Great for travel and powered by RunStretch technology around 12 hours of playtime. TWS Pairing: Pair it with another StormBox Micro 2 speaker to enable Stereo Mode and enjoy more immersive sound indoors or out. Travel and Outdoor Friendly: Small enough to fit in your pocket, bold enough to be shown to the world with the integrated strap. The StormBox Micro 2 can be clipped to anything from your backpack to tree branches, bike handlebars, or a belt loop.