@l_lama
I don't use Fidelity IQ and don't plan to use it either, as I don't see any benefit in it for me.
There are three reasons for this:
1. I can hear louder when I use Dirac Live, so loudness correction isn't absolutely necessary and I don't miss anything. Of course, the reverberation remains high and does not go away (I would need more than a subwoofer, etc. for that), but despite everything, Dirac takes some energy out of the room modes so that you can listen louder before it becomes too much. This means that loudness correction does not make sense for me here.
2. Some signals (especially from the TV) are quite bass-heavy, so loudness correction doesn't make sense here either, as it would simply be too much.
3. I want to avoid Dirac Live and Fidelity IQ negatively influencing each other in the end.
Regarding point 2:
One of the main uses of my system is for watching television. I have the impression that the sound signal sometimes has an increase in bass and treble. In my opinion, this is understandable, as most people only use the small speakers built into the television or a soundbar, which does not have the playback quality of a large stereo system.
To make it sound better or fuller, I can imagine that the bass and treble are boosted, especially in the upper bass range. Small TVs can't really handle low frequencies, and I have my doubts about soundbars as well.
I therefore use a linear target curve in Dirac Live with a boost of +1dB to the bass and treble respectively and don't miss any loudness compensation. On the contrary, with some TV programs, you're almost shocked at how good the sound is (despite the fairly flat target curve in Dirac), but that could also be due to the KEF speakers. If I were to compensate for loudness here, it would certainly sound too rich.
For music, the target curve with +1dB in bass and treble may sound a little too flat, but I have stored other curves in the Onkyo and can switch accordingly or permanently store a different target curve for the input of the streamer or record player.