The Freq response posted from Paradigm website
Frequency Response:
On-Axis ----------------±2 dB from 39 Hz - 45 kHz
30° Off-Axis ---------- ±2 dB from 39 Hz - 20 kHz
Couldn't find any third party of the latest iteration of the S8's
I know darn well I can't hear anything above 18k hz, so any numbers stated up high are worthless to me IMO.
From my perspective these speakers response are pretty close.... I auditioned them together and walked away with the Sigs... Ultimately, you can look at measurements all day long, you really need to audition them together and figure out which sounds the best to you... I though the Sigs were closer to the 802D's then the 803D's, but thats just me. I can't decide for you, I can only decide for myself...