IMO, the standard for "bad" sound has changed a lot, and today, even a 13 USD novelty bluetooth speaker can have class D amplification and DSP, offering much less audible distortion than cheap products in the past. The frequency response is a deliberate choice, aimed at maximizing the sense of clarity, particularly with spoken word. And for a driver measuring less than 40 mm in diameter, it works remarkably well. There's obviously no real bass or treble, but it actually sounds pretty good for what it is, and intelligibility of spoken word is great. I imagine that smartphone speakers employ similar tricks. Rather than purchase a rather obscure and discontinued Tivoli product as Cube, have you considered using smartphones and popular portable speakers as your lo-fi reference?
I owned an early Tivoli Model One radio, and I imagine that despite unchanged model designation and external appearance, there have been a few changes made internally over the years, with addition of DSP being an obvious possibility. At the time, I did not know how to perform a frequency sweep, but recalled the on-axis sound at modest listening volumes and ~1 meter being pleasant. But off-axis and at greater distances, or off-axis, intelligibility of spoken word was not so good, and it didn't get very loud. But whether the 2024 version sounds the same as the one I purchased nearly a quarter-century ago, I couldn't say.
