the question comes to mind -- with what did you play it back on and did they have thier room set up for SMPTE 202M (whiich is fairly flat right in front of the screen or some other setting (common if they also screen digital and/or dvd mixes) . They may have different presets for the A chain, but will leave the B chain alone (ussually)

One of the unique and interesting aspects of cinema sound is the X-curve. "Curve X" is described in ANSI PH22.202M-1984 / SMPTE 202M as a high frequency roll-off for a typical 500 seat theatre of 3 dB per octave beginning at 2KHz, and 6 dB per octave at 10KHz. Correction factors are given for other sizes of theatres – something that is largely overlooked in this industry! All cinema playback systems today are aligned to the X-Curve. The history of the X-curve begins with Dolby’s early attempts to promote faithful reproduction of sound in theatres with fairly common and not too sophisticated measurement techniques. X-curve resulted from a study of cinema acoustics across the country some 25 years ago. The frequency response described by X-curve was designed to compensate for the reverberation and screen roll-off of the average theatre, giving a uniform static frequency response to which all rooms are to be adjusted.

The problem with X-curve is that it is now 25 years old, and it is questionable that the average theatre room acoustics found today are the same as those when the standard was created. We have lost sight of the fact that the goal is to achieve a flat spectral response in the room after environmental conditions such as room reverberation and air absorption are taken into account. Instead, X-Curve has become an end to itself. The most obvious aberration that it has caused is the Home THX "re-EQ" standard in Home THX-approved receivers, which serves as a translation of X-curve, originally meant for large theatres, to very small room acoustics. The industry would be better served by adopting a suite of curves that represent a variety of room sizes with various reverberation responses, and employing sophisticated analysis and alignment in the studios.

On the subject of theatre alignments, it is worth discussing the 10dB on in-band gain required of Dolby Digital in the Subwoofer channel. The Dolby DA20, Dolby’s stand-alone playback product for decoding Dolby Digital films, produces a reference level output for all channels with Dolby’s test film, including the Subwoofer channel. Once the Subwoofer response is flattened and the 1/3 octave levels are set to match those of the screen speakers, Dolby requires the Subwoofer level to be increased an additional 10dB. The Subwoofer track will be recorded 10dB lower than otherwise by introducing this boost in the acoustic mixing environment. While the 10dB of extra headroom is not necessary for digital tracks, according to David Gray of Dolby Laboratories, "it's a practice that carried over from 70mm magnetic film track production". Although not so in earlier days, all digital formats now observe the 10dB boost for the Subwoofer track.


quoting from audio design labs:

I would say that most "modern" soundtracks are not tweaked all that much (if at all) in the HF region. Also, when a THX disc is mastered they are typically monitoring on a system which uses THX Re-EQ (THX pm3 certified rooms are required to be equipped with this). THX RE-EQ is a very slight "tweak" on the HF and is not equal to the X-Curve (which is a dramatic roll off).

"Just so you understand, the X-Curve is mostly an anomaly of how the playback system is measured during calibration. If you measure a big cinema system at less than a meter (close mic), it measures flat (or very close). As you move away from the source, the HF begins to drop off naturally. Your ear / mind actually expects this roll-off and if you try to EQ the system flat in the far field it doesn't sound good. The X curve is the standard for this far field roll off and varies slightly by room volume. However, Tom Holman figured that the mandated X curve roll off that the cinema systems are EQ'd to is slightly to steep on the top end. This means that the top end of many mixes sound a little bright. RE-EQ takes care of this differnence in HF response. In a perfect world, according to Tom Holman, SMPTE 202M (X-curve) would have slightly less (or a different) roll-off and there would be no need for Re-EQ."