... response: 150Hz-18kHz 3.Good quality and best price Mini speaker: 1. Output: RMS 6W.2. Frequence response ... Signal to noise ration(SNR): ≥80DB.4. Loud speaker: 1.8 inch (external diameter: 45mm).5. Magetic ... : 4Ohms.6. Sopport: USB and SD card.7. Color selectable: blue, pink, green, silver, black, ect. ... . Portable Micro SD mini Speaker (just for mp3 mp4 tablet pc ,mobile phone,USB flash driver, SD card ...