Here's the
comparison between the 2.
LP-6v2:
Bass extension: 39Hz at -6dB
Preference Score is 5.9 and would be 7.7 with a perfect subwoofer.
LP-8v2:
Bass extension: 35Hz at -6dB
Preference Score is 5.1 and would be 6.8 with a perfect subwoofer.
I don't think you'll notice the deeper bass (only 4hz) ...when playing at lower volumes.
At higher volumes (as visible by Erin's Response Linearity test), the limiter kicks in for LP-6v2 earlier, which cuts off the bass, whereas Lp-8v2's limiter won't kick in until lower frequency.
You can read the preference score using the patent from Sean Olive:
A general model is provided for predicting a loudspeaker preference rating, where the model's predicted loudspeaker preference rating is calculated based upon the sum of a plurality of weighted independent variables that statistically quantify amplitude deviations in a loudspeaker frequency...
patents.google.com
Also, Erin did an interview with Sean Olive talking about the preference score, here: