Why are some movie parts much louder than others?
This is a major hassle for me because I like watching movies late at night and I live in a city row house where neighbors sometimes complain of noise. When I have the volume set to something reasonable during the regular conversation parts of the movie, that same system volume level outputs a significantly louder sound when some violence kicks in or the soundtrack to the extent of having to rush to my remote to turn it down. Then I have to turn it back up when it's over because I can't hear conversations at the same volume level at which this increased input volume was tolerable. I also have some delicate sensory sensitivities (I can't handle very loud or certain sounds) so this is a problem.
I have never experienced this situation where I actually found the drastic variation in the sound volume something justified, which made the movie more enjoyable. IOW, I always find it a hassle.
Why are some movie parts much louder than others?
My entertainment setup consists of a projector, DVD player, Roku box for streaming, Sony receiver, and a 5+sub Harman Kardon speakers. You could say it is a fairly sophisticated setup and I wouldn't mind, if possible, to configure some setting to make the sound level more uniform coming out of the receiver regardless of how the input is encoded.
Best Answer
This is called dynamic range. In the simplest terms, imagine that you have a fixed numeric scale from 1 to 100 which tells you how loud something is, and you want all sounds in your recording to be reasonably representative of the actual sounds within the context of all the other sounds in the recording.
So for an action movie, you want the explosions to be 100 and "ambient silence" to be 1. Everything else needs to be in the middle somewhere and still be believable: you want gunshots at point blank to be louder than casual conversation.
If you adjust volume for listening to dialog, now the other stuff is booming. But if the audio engineer sets the dialog at 80, now the gunshots sound like popcorn. Sort of a catch-22.
As for how to mitigate this, some TVs or receivers have "low dynamic range" or "quiet mode" etc. setting in the audio preferences. Most dialog is in the center channel, so you can try lowering the volume of the other channels. I have found that choosing "stereo" instead of 5.1 can improve the volume level of dialog.
Some of the methods for "fixing" this on the fly involve look-ahead methods which can introduce time delay between video and audio. Not a big deal for devices which allow for adjustment (my TV has a latency setting).
Further google/reading: "loudness war" "dynamic range audio"
Pictures about "Why are some movie parts much louder than others?"
How do you fix movies that are really quiet then really loud?
This is because movies are recorded at a lower volume than normal TV. These tips can help make it easier to hear everything that is going on. Most movies are recorded at a lower decibel range than live TV and the audio is optimized for 5.1 playback.Why are some movies volume low?
Most TV commercials are created to be loud simply so you can hear the advertisement and get your attention. The Federal Communications Commission (FCC) does not regulate the volume of commercials, nor does it regulate the volume of TV programs.Why are some shows louder than others?
How to Fix Movies that Are Really Quiet, then REALLY LOUDWhy does the volume change when watching movies? | Why is action loud and dialog soft when watching
More answers regarding why are some movie parts much louder than others?
Answer 2
Check your TV or receiver for audio settings. My TV has a couple different ones, one of which acts as a normalizer which keeps the volume pretty much at a set peak. Another one brings the voices more out front, which is important because I don't have a home theater in my bedroom and when the audio is on "Movie" setting all I hear are the built-in speakers rattling.
As for your original question of why, it's all part of building a dynamic or a mood. Try watching Jaws or any horror movie on mute and see how much of a different experience certain scenes are versus with the volume on.
Answer 3
In Pro Sound (live music/dj/etc) the thing we would use to rectify this either overall or for one part (an electric bass guitar is a common example) would be a compressor or limiter.
A compressor will bring quiet sound up to a minimum level and prevent sound from exceeding a certain level. A limiter just does the former. There are some available specifically for home theater/audiophile setups.
As the other answers have mentioned, your best bet is to reduce the transmission of vibrations to the walls and floors. These will be either directly from the speakers or indirectly through the air. Foam strips to give the speakers a bit of gap between them and the mount can help a lot. Acoustic padding or paneling for the walls can also help.
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Karolina Grabowska, Ketut Subiyanto, Ketut Subiyanto, Ketut Subiyanto