You get a surprisingly high-fidelity and full range bass tone from one of these. Even my 5-string actually sounded very nice. Don't expect earth shattering bass or loud volume, of course - it is really a "heard clearly, rather than felt in your chest" type tone as you'd expect from a driver this size. Enough volume for solo practice at home, recording, maybe even quiet acoustic jams with friends, but definitely nothing louder. The compressor is a practical addition on top.
If I had to nitpick about something, it's that the Bluetooth audio signal sounds quite boxy, tubby and weird compared to the very decent bass guitar tones you can get out of this. However, you can't expect miracles from a box this small and cheap, and it's still awesome you have BT built in to wirelessly stream a drum loop or a backing track to practise with.
Ultimately I felt a headphone-based practise setup was easier and better sounding for me - and if I need a "small amp", I can carry around a slightly bigger setup with less compromise in volume level, say, 1x10". So I did end up returning the amp to Thomann.
But for someone who actually specifically needs a quiet practice or recording amp at home, feels like the bigger alternatives are too large or expensive, and doesn't enjoy practising with headphones on, I'd highly recommend one of these.
