I own a Bistab and used it in a theatre piece that I toured with my group for several years. Depending on the space we were performing in it could sound quite full ((but never straight up loud) but other times it was too quiet to feel really present in the space. This was largely dependent on room acoustics; for larger or drier spaces we would use a bit of amplification (and a touch of reverb). Also, the volume is dependent on how much of a charge the Bistab has. At lower charges it is quieter, but also unstable in terms of tuning (ha!) etc.
In order to bring it in softly, I would press the instrument against my body so that the speaker was slightly muffled and then bring it away from my body as I wanted to increase volume. I found that I could manage dynamics pretty well this way.
Since the Bistab uses square waves it will sound louder than the Thyris or Phashi so if you were really concerned you could go for one of those. I chose this Bistab because I was going to be singing with it (a version of the anti-fascist anthem Bella Ciao), so I needed something that could be perceived as loud enough to match my (unamplified) voice.
That was a long post but it’s not often I get to talk about the Bistab! I have a very intimate relationship with mine; I love its strangeness, its moodiness. I never new exactly what was going to happen when I picked it up; the moment in the performance needed to be super delicate and here I am trying to convince the electronic equivalent of a cornered raccoon to play a song with me.
