Fader adjustments from trailer to feature

[Randy Stankey]

...your ears will get used and ‘dampen’ such soundtracks where it’s loud-loud-loud all the time. ...

One of our patrons at Mercyhurst was an otolaryngologist ("E.N.T." doctor) and I had a couple of conversations with him about how the body reacts to sound. He told me that there are muscles inside the ear that can alter the tension of the eardrum, making the ear more or less sensitive to sounds, in order to protect hearing from excessively loud sounds. After a period of time, these muscles can stiffen the eardrum, making it less sensitive. When the loud sound goes away, the eardrum is relaxed, restoring normal hearing.

He told me that one of the biggest dangers to hearing is impulse noise. Loud sounds that occur over a short duration don't give the eardrums time to react and protect themselves. Gunshots or explosions are prime examples but he said that movie theaters present a kind of hidden danger because the sound systems can produce loud, short duration, impulse noises that occur repeatedly and so quickly that the ear has no way to protect itself.

The guy was a kahuna in this town so I, pretty much, take his word.

[Marco Giustini]

Indeed, that’s exactly what I meant, Randy. Those little muscles dampening your perception and why an isolated ‘gunshot’ will appear more effective than blasting 100+ dB of sound for 40m uninterrupted.

[Carsten Kurz]

Another high-performer, 'Sound of Falling' Trailer comes with an LEQ(m) of 85. This is really not a movie where galaxies collapse. And clearly it is happening a lot more frequently in recent months. I actually had to relevel this trailer in DCP-o-matic by -6dB to get it into a range that we can cope with our limited set of Macros. We play it at 3.8 on our AP20, and it's still too loud for the type of content at least.

[Steve Guttag]

Marco, as for response from that theatre...pretty much textbook:

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The subwoofers used where the QSC SB-15121 (Screen channels are SC-424/Quad-amped).

I guess there is truth in advertising, this is the graph of the subwoofer's published response:

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It isn't hard to see that to tune it, one will mostly need shelving filters, like one around 40-45Hz to bring the higher frequencies down and/or one around 100Hz to bring lower frequencies up. However, it drops like a rock below 25Hz. The subwoofers (and screen channels) are mounted in a baffle wall...so, it had 2π space. You'll get a deeper response on an SB-7218 with B6 alignment. The boast about the SB-15121 not needing B6 is lost on the fact it needs the shelving filters that, effectively cost it sensitivity.