Loudspeaker for mobile, with base plate

A compact loudspeaker that serves as a sound source for acoustics experiments, connecting to a mobile phone, tablet or PC/notebook. The metallic aluminium housing has controls for play/pause, volume and track selection, an on/off switch and a rugged grille, and it accepts audio via USB, Bluetooth, a memory card (Micro SD/TF up to 32 GB) or a USB stick, with a 3.5 mm headphone socket. Speaker: Ø 45 mm, 4 Ω, 3 W, frequency range approx. 40–11,000 Hz; a 3.7 V / 600 mAh lithium-ion battery (approx. 8–9 h play, 3–4 h charge) or a 5 V DC supply with USB cable (included). It comes on a device-shaped plastic base plate; speaker 50 x 50 x 50 mm, base 120 x 90 x 25 mm, complete set 159 g.