I'll paraphrase what Randy posted from their site:

The AVR plays a test tone (which based on what they're saying is probably pink noise - there's no really good reason to mathematically alter a perfect "control" tone) and then plots the frequency response in the room.

The big whiz-bangy thing they go on and on about and how much better it is that a parametric EQ is explained a bit more complicated than it has to be.

First, a parametric EQ - it works by setting a target (centre) frequency and bandwidth (or Q if you prefer)... let's take a "tuning A" as the frequency - 440Hz let's say it's 75dB SPL as a reference level. Let's say the bandwidth (or "Q") is one octave each side, and say we crank up the gain on that target frequency by 3dB with a parametric EQ, now at 440Hz the amplitude will be 78dB SPL (the full 3dB gain in gain) and draw a rounded curve down to 220Hz (one octave lower) and 880Hz (one octave higher) at the reference level. That's how you shape a sound with a parametric EQ (with multiple target frequencies of course). Here's a diagram of what about an 10dB cut looks like.


What it would seem they're doing is applying a graphic equalizer to the spectrum analysis of the room and speakers. That looks kind of like this (look at the pale green bars, ignore the faders):

So if that was the spectrum analysis of pink noise in a room, you'd want ideally for all those bars (which refer to the amplitude of different frequencies) to all line up at 0. I can't read the marking on the image, but you'd want to boost the first bar frequency band, oh, looks like about 7dB (assuming that's a -6 marked near it?), the second bar about 4, the third bar you'd want to cut by about 4dB, etc.

Either way you're graphing a set of speakers' response in a room and correcting it to a known control (pink noise - even power across all frequencies).

Normally in professional audio, you use a parametric EQ to shape the sound of an instrument and a graphic EQ to even out a room's character, but either one will get you there in the end... they do the same things, just differently.

Hope that makes more sense than Randy's cut-and-paste.

Bren R.