With Easy Install Beat Booster you can increase the audio input volume. Installation without soldering or cutting any wire. You can use your pt01 without external speaker.
$40 – Visaton FRS speaker full-range speaker 5 cm (2″) full-range speaker with black basket and two fixing lugs. Due to its low resonant frequency the frequency response starts already at 120 Hz. Suitable as full-range speaker and medium-range driver in speaker systems for HiFi and background music and for 100 V PA systems. Thanks to the slim construction, also suitable as a control speaker in electronic devices.