The only Genelecs I've measured are my 1029As, and they're sensibly flat when measured pseudo-anechoically. In-room with a normally furnished room they have the expected downward sloping response, but of course can be equalised flat in-room. Doing so will make them sound undesirably bright.
Although I don't agree with the ITU and EBU recommendation for a home listening room, I understand why they specify that for monitoring broadcasts. Listening to a broadcast or a production isn't done for pleasure, it's a job of work, and firstly, by standardising on a flat in-room response, that makes it easier when moving from one room to the next. Sound engineers in broadcast studios often have to work on the same piece in different rooms, so a standard in-room response avoids any acclimatisation time moving from one room to the next. They could have just as easily specified a 'house curve' with a downward tilt.
Secondly, having the sound somewhat bright highlights any issues with speech sibilants as well as bringing up distortion and other undesirable noises. This isn't necessarily a problem unless the sound is then equalised to remove the brightness.....
S.
I’m not sure I agree on the value of spec’ing a target in-room response, even for broadcast purposes.
The research makes it difficult to escape the conclusion IMO that even where a given pair of speakers is EQ’d to a target room curve we will (mostly) hear the speakers rather than the room. So if hitting this target involves tilting the anechoic response of the speakers upward to compensate for a downward sloping power response and/or the absorption properties of the room, the result will be that different speakers that require different EQ to reach the same in-room target will sound very different.
Or to put it another way, two different speakers equalised for a flat in-room response are likely to sound more different than two flat-measuring speaker in two different rooms.
It would make more sense IMHO if the standard spec’d the speaker’s response and focused on other aspects of the room’s acoustics, eg RT times, dimensions, absorption/diffusion ratios, etc, as opposed to target room response (IIRC it does this too FWIW, but it’s been a while since I looked at it).
If a bright/lean response really is beneficial for this type of work (not sure I’m sold on that one either tbh but that’s another story), this would be achieved with more consistent (ie psychoacoustically consistent) results by spec’ing a leaner loudspeaker response and heavier low frequency absorption.