The automatic setup program offers four options for setting the bandwidth, gain, and Q of the
parametric equalizer blocks in each channel:
When I substituted the Ultra for the F1800RII and then did the same measurement (after adjusting the
parametric equalizer in the SV sub) I got a curve in the bass range that looked just like that IC-20/F1800RII curve--but with 2 dB lopped off the peak at 50 Hz.
(www.infinitysystems.com) Basically the Kit is a complement to the single-band, half-octave, cut-only,
parametric equalizer built into the Prelude and Intermezzo subwoofers.
However, the dip at the higher frequencies is only one-third octave wide at the bottom, and so even at its narrow-width setting of .7 octave, the
parametric equalizer could not effectively eliminate it.
For $50 more, consider upgrading to the new AVR 2106, with user-adjustable seven channels of digital equalization, its automatic speaker and room calibration system with six
parametric equalizers, and a slightly higher power rating.