The Bose S1 Pro Plus has decent frequency response accuracy. It has an Auto EQ setting that’s turned on by default, automatically adjusting the speaker’s sound based on its orientation. As a result, you get an optimal listening experience for each of the four positions available.
We tested the speaker in a vertical orientation, sitting flat. The overall sound is quite balanced, especially in the mids, where most voices and instruments reproduce. The touch of extra emphasis in the high-bass also adds some warmth to the mix. There isn’t a huge difference in the speaker’s sound when you set it up in any of the other positions, as you can see from the graph here. Additionally, this graph shows you a comparison of the speaker’s performance when it’s plugged in or using battery power over both a Bluetooth and an AUX connection. As you can see, there’s very little difference in the speaker’s performance here. As a result, you can set it up in the most convenient way for you while enjoying a consistent sound.
