The Energy Slider is probably referring to a simplified control that combines several technical parameters, such as bass, mids and treble into a adjustment bar. Moreover, it probably works the same way EQ works on the nothing and cmf buds, but it works as a general indicator of the sound’s liveliness. Moving the slider changes the gain of certain frequency bands at once to deliver a different character to the sound.
Can’t wait to see them! Good luck to everyone!!
