I've just used the Adyssey Multi EQ app for the first time, and I don't understand why the target curve contains a roll-off in the base and in the upper high range. I'm sure this has been asked many times, but I couldn't find an answer. My front speakers are reasonably hefty transmission line floorstanders, they are quite capable of room-shaking deep base (by "deep" I mean below 30 Hz), and they are set to "Large" - they should not be dialed down in the base region, and yet even for the L/R target curve rolls off the base.
So I guess my question is two-fold:
1) What is the reason they made the curve roll off on both ends way before sub-sonic base and ultra-sonic HF range? If they EQed from 15 Hz down and from 20 kHz up I wouldn't mind, I think that would have made perfect sense.
2) Should I use the curve editor to try to flatten it out on either end? That's very hard to do in the mobile app, by the way.
An additional observation: I've experimented with setting the filter cut-off frequency (the highest frequency up to which Audyssey will apply EQ) to 20 kHz, to 500 Hz, and finally to 20 Hz. I gave all 3 options a quick listen on a decently detail-rich and bass-rich piece of music, and couldn't hear any difference. Isn't that odd?
I'll try it with a tone generator and an SPL meter later to see if it really does EQ the base and the treble as expected.