I've heard a few. What are you using?
it was the fixing of "bad loudspeaker coloration" notion with regards to AVR's room correction & EQ setup shenanigans that I was struggling with.
of course I realise & accept that all speakers have their limitations etc and no speaker is perfect and that there are loads of speakers that 'under-perform' (in all sorts of ways, whether we're talking about frequency response, imaging, power handling, etc..) but I don't agree that it is the job of Audyssey (or any of the other room EQ routines built into AVRs nowadays, whether proprietary affairs such as Yamaha's YPAO or Pioneer's MCACC or the likes of Audyssey that's used by Denon/Marantz, Onkyo, etc.) to rectify "bad" or 'poor' speakers.
Audyssey's MultEQ and its variants and its competitors are there to cure problematic rooms & things like less than ideal speaker positioning - the people behind these EQ technologies say so themselves, as I referenced Audyssey's own blurb in my previous post here in this thread.
I don't profess to be running "good speakers" in a perfect listening environment by any means.. I'd like to meet the man who does. I expect Audyssey etc to overcome the shortcomings of my room & speaker layout but not the shortcomings of my speakers, I'm aware of how imperfect they are.. for one thing they're anything but 'flat', tuned to be warm-sounding with a notched treble, it'd be unfair to expect Audyssey to 'cure' the speakers' own sonic signature as they were designed to perform.. however, I have a problem with an auto-EQ setup routine that then rolls off the top-end of such warm speakers even further, needlessly boosting their bass and killing what treble response they have by massively cutting it.
By my observation and in my humble estimation, if Audyssey was designed to 'improve' speakers then in my situation it would 'flatten' them by taming their bass and boosting their treble, when it does the exact opposite for me in my listening environment with my speakers & cabling etc., I don't like the results, so I don't use it but I'm sure it works for a lot of people and they're very happy with it and I'm happy for them!