I had the S400 mk II speakers, which are rated at 87 dB, in my bedroom. During low-level listening sessions at around 45 dB at night, I found that, with well-recorded music, I could discern articulated bass notes and open, airy treble without any difficulty. To maximize my listening enjoyment, I would activate the preset EQ in Foobar2000, adjusting the SPL to match a spectrum of multiband frequencies according to F-M-based equalized loudness curves (as described below). It’s important to note that if the resulting dB levels at certain frequencies approach the distortion threshold, it’s advisable to lower the entire spectrum of dB levels by the same amount.

