This mobile speaker is used by my mom for square dancing and playing music, so the volume is put all the way up, and can't be broken and not enough volume. That 8-inch sound unit, the sound is loud and clear, penetrating, wide spread, their hundreds of square dance group, everyone heard very clearly, and never appeared to break the sound and inaudible situation. Sony Ericsson SA-T11 also has a Bluetooth transmission wireless transmission function, of course, if you will not use the phone Bluetooth, you can use through the wired AUX, U disk and TF card to provide audio sources for playback.