Originally Posted by Cam Man
Thanks again. Even reading that, I'm not sure I would have understood it to be what it really is.
In looking at most of these I see what is common to all mixes where a big impression is to be made with bass. The 30 Hz to 50 Hz range is where we really get the hitting power we hear and feel. That is where the mixers have appropriately mixed the highest amplitude in the event. My question to all, and I'd certainly like to see Filmmixer and others ring in on, is how much content below 30 Hz is intentional; not just stuff that falls down there because it's not even being monitored that low? In other words, is it a happy surprise for those who want to mine it, but otherwise unintended?
It makes me wonder why there is such passionate pursuit of subs that reach into the teens when there is so little there (content and amplitude).
You're hitting on a debate that has been ongoing here for at least 10 years, and is completely settled. I'll boil down the salient points so you don't have to wade through this and other threads' thousands of posts on the subject, although I feel like I've done this within even the last few months.
1) The content is intentional in almost all cases. Because we experience a huge amount of reasonably high-amplitude sounds below 20Hz in our daily lives (as proven in a whole slew of posts by bossobass, maxmercy, FOH, myself and others), it makes sense that these sounds are recorded and utilized in foley, sound design and mixing, especially to add a sense of realism and immersive quality to the mix.
The best of the best mixers and designers know this, and it is from these Academy Award-winning sound professionals that we have tons of content in these octaves. At this point in the march of technological progress, it is only when they are filtered out by design that we take note. There are a number of mixing studios that either do have or have had the capability to reproduce content significantly below 20Hz, most notably Skywalker.
Thusfar, out of over 300 movies maxmercy and I have measured, some 80% have a -10dB point below 20Hz, 62% have a -10dB point below 16Hz, and 50% have a -10dB point below 12Hz, and an astonishing 46% have a -10dB point below 10Hz
. There is no possible way that's unintentional noise, especially when you look at graphs of the spectral content in most of these very low effects.
2) The range of 25-35Hz is where most of the resonant frequencies that excite objects (and our bodies) exist, but the octaves below that are what excite our home and home theater structures. This is part of the reason why content below 20Hz reproduced in rooms with suspended floors creates such an amazing effect. Above that, or in rooms on concrete slabs, not so much.
To your point, though, the Fletcher & Munson Equal Loudness Contours show that high-amplitude stuff in the bandwidth you noted will likely sound louder, and further research dictates that it may be perceived as "better" simply because of that apparent loudness.
3) I made a post a couple months ago about the limitations of presentations that cannot reproduce all of the content on the disc, no matter the amplitude. It informs some of your questions and supports some of my assertions. Please do read through it and all
of the supporting links. It can be found here:
4) Look up posts by bossobass on this and the Data-Bass.com forums, and specifically the keyword "intentional." You'll find a wealth of information and proof that has helped inform my own research on the subject.
Please read through all of the supporting material. Your inquiries and assertions have been addressed multiple times in the past, and if you fully immerse yourself in the supporting documentation I've pointed you to, you'll find that you won't have to ask this again, and you might even be able to educate the professionals you interact with in related areas of professional and personal interest.