"Cambridge’s dCS announced their 1.1.1 Mosaic update to the Bartók DAC and headphone amplifier adding Expanse, a DSP designed to bring the headphone listening experience ‘closer to the sound artists and engineers hear when listening to a performance mix in the studio’.
In front of a loudspeaker system, each ear hears the sound of both loudspeakers plus a plethora of reflected sound; commonly referred to as reverb. But listen to that same recording behind headphones and the left ear only receives left channel information and the right ear only receives right channel information. And with the room effectively removed by headphones, there is no reverb. For dCS’s engineers, this imbalance between loudspeaker and headphone listening was a problem in need of a solution."
In initial listening I was afraid it might sound like flipping a “reverb” switch on other systems, but it is quite subtle. Expanse adds a nice touch to certain tracks.