Validity of X-curve For Cinema Sound

[Andysu]

if Dolby Stereo is set up correctly with multiple surrounds , left right - half surrounds around the room , plus a lot more besides that , first got have proper Dolby cinema processor , Glory presented in lucasfilm ltd THX sound system , x curve

one of few demo Dolby Stereo movies here in this THX cinema

 

[Andysu]

Dolby Stereo CP200 in selected THX cinema

 

[Frontino]

Dolby measure it using RTA / pink. And yes the goal is flat response from the speakers. (I.e. In a lot of cases, once a speaker system is calibrated to be "flat" in a large room, it'll be fairly close to the x-curve, but there are a ton of variables that can throw the correlation out if you're unlucky, obviously)

Hi. I've found this post on Avid community:
https://duc.avid.com/showpost.php?p=2671263&postcount=304

Is that true? The new target now is 82.5 dBA with the X curve?

 

[audio2920]

Well, I've never seen it done that way but it makes some sense I guess. If you're in a room where it makes sense to be on X-curve though, then the C-weighting at 85 should achieve the same level, unless you have FR issues. So I'm not sure it's a material change in spec..?

I guess it's more just a quick and dirty way of discarding upper and lower frequencies if / incase they're out of whack (for whatever reason) and make sure the dialogue band is broadly where it should be.

 

[Andysu]

great names in sound , JBL professional cinema , Dolby Stereo " x curve 85dB ref " , lucasfim ltd THX sound system and pioneer laserdisc