Sony ULT Field 1 Portable Bluetooth Speaker

To experience the true power of the SRS-ULT10, simply press the ULT button and you'll hear the ULT POWER SOUND difference. The bass is boosted, adding more depth and resonance to the lower frequencies, while the sound pressure is increased to inject more energy and volume into the music than might seem possible from a speaker so small. It’s a stunning audio performance from such a compact device.