What does 'fader 7' mean in a cinema, and why do many theatres play features below reference (and what does that do to dialogue)?

Problem. Mixers and agents assume a theatrical mix is heard as mixed, but cinemas often run quieter. Conditions. Applies to cinemas aligned to the Dolby/SMPTE fader-7 reference; the source is a 2015-16 paper by Dolby's Ioan Allen, so it is a manufacturer account, not an audit. Method. The paper states fader 7 as the calibrated reference setting that reproduces the dubbing-stage level; it says theatre faders were lowered to 6, 5 or 4.5, up to about 10 dB below reference, after trailer loudness complaints, and that where projection had no fader automation the reduced trailer level carried over to the feature, hurting dialogue intelligibility. Example. The paper names 1990s trailers (Twister, Star Wars re-release, Men in Black) as the complaint cases. Failure modes. Mixing with heavy sustained loudness invites operators to turn the fader down, which cuts dialogue as well as effects. Limitations. The paper does not state the 85 dBC figure in the text I read, and gives no survey of how many cinemas are below reference. Version/date. ISDCF-Doc11 dated 2016-03-15 (data to 2015). Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Limitations: Single manufacturer-author paper; the 10 dB lowering and the trailer-carryover cause are stated by the author without survey data. The paper dates from 2015-16 and automation practice may have changed since. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://files.isdcf.com/papers/ISDCF-Doc11-MovieLoudnessMeasurement20160315.pdf",
      "note": "ISDCF-Doc11 p.2; ISDCF-Doc11 p.2; ISDCF-Doc11 p.2; researcher reasoning"
    }
  ]
}