Why aren't cinemas targeting sub 20hz response?

[smallricey]

Our hearing stops at 20 hz. Seems enough if subs do the same. I seem to remember one reason is with hearing below 20 hz we'd hear our joints creaking.

Plus there is the chance to make people sick, queasy or see illusions at high levels below 20 hz.

I think I can hear shit at 15hz...no joke. 15hz - 15khaz.

 

[North_Sky]

 

[smallricey]

Then you must be an elephant.

? Am I?

 

[smallricey]

It was humor; you're not an elephant, you're a person...a human.

? Is it?

 

[smallricey]

No, I'm sure you are an elephant who learned how to type.

? No?

 

[Kvalsvoll]

Mostly because it is very hard to achieve useful output below 20Hz in a cinema, due to the size of the room, and partly because they have no idea why ulf makes a difference.

But you are 10 years late. Go to data-bass, lots of info there. I also recommend my article about bass-eq, as an introduction to what this is about. Never mind the bass-eq details, read the why and what, and don't worry so much about how:
Bass-eq-for-movies-how-to-improve-sound-quality-on-bass-filtered-movies

 

[trl]

I think I can hear shit at 15hz...no joke. 15hz - 15khaz.

Well, possible, but quite difficult to realize that, because you might actually hear the 2nd order harmonic. It happened the same to me too for couple of times, but REW opened up my eyes and ears.

 

[sigbergaudio]

Mostly because it is very hard to achieve useful output below 20Hz in a cinema, due to the size of the room, and partly because they have no idea why ulf makes a difference.

But you are 10 years late. Go to data-bass, lots of info there. I also recommend my article about bass-eq, as an introduction to what this is about. Never mind the bass-eq details, read the why and what, and don't worry so much about how:
Bass-eq-for-movies-how-to-improve-sound-quality-on-bass-filtered-movies

Not sure exactly what I'm 10 years late to, but I'm aware of data-bass, great site! Interesting article, but not feasible for the average consumer to manually apply custom EQ per movie. And the fact that a lot (most?) movies apply heavy high pass filtering indicates high output below 20hz won't actually add much in most cases (unless you do as suggested in your article).

 

[Frank Dernie]

So I shouldn't count on you for a ride?

I would be delighted to give you a ride. You wouldn't be permanently fixed in place.

As a matter of interest in racing weight is so important that big drivers rarely used to get through the lower formulae because their weight is too big a disadvantage.
In F1 10 kg is a loss of about 0.35 secs per lap which is huge, for quite a few years now the minimum weight limit has included driver weight so bigger guys are getting in. Mind you "big" will be 72kg....

 

[SIY]

I would be delighted to give you a ride. You wouldn't be permanently fixed in place.

As a matter of interest in racing weight is so important that big drivers rarely used to get through the lower formulae because their weight is too big a disadvantage.
In F1 10 kg is a loss of about 0.35 secs per lap which is huge, for quite a few years now the minimum weight limit has included driver weight so bigger guys are getting in. Mind you "big" will be 72kg....

I think I was last 72kg when I was 10 years old.

 

[FrantzM]

I think I was last 72kg when I was 10 years old.

You were quite substantial, then ...

On-Topics.

It could well be that sub-20 Hz are unitentional, I would like references to Sound Engineers explaining this.

I also would like some references to proper low frequencies extension masking higher but still low response. It could well be but I would appreciate solid references.

 

[Chromatischism]

I also would like some references to proper low frequencies extension masking higher but still low response. It could well be but I would appreciate solid references.

I don't have a reference but I'll add it's the reason why people think sealed speakers have "tighter bass" even if they objectively don't.

 

[Kvalsvoll]

Not sure exactly what I'm 10 years late to, but I'm aware of data-bass, great site! Interesting article, but not feasible for the average consumer to manually apply custom EQ per movie. And the fact that a lot (most?) movies apply heavy high pass filtering indicates high output below 20hz won't actually add much in most cases (unless you do as suggested in your article).

It was not targeted only at you, more like most readers on asr. The comments in this thread reveals questions we asked ourselves many years ago. Questions we discussed, then did experiments on, and found the answers for.

If the average consumer does not apply bass-eq, then the average customer will not achieve good bass response for most movies. Not that it would help, you also need a decent properly calibrated bass-system, and the average customer does not have that either.

Since you read Norwegian language, you can find 2 articles on my page about Sub-bass. Part 1 is about what it is - perception, part 2 is about content - what is there. If I had English translations for those, I would have placed links in my previous post, but that does not exist, and a googels-translate is not good enough.

But many movies are full-range, and even more are in the category that only needs a gentle lift at the low end. Examples of good out-of-the-box movies are The Martian, Hanna, Inception. Of those that needs some lift, all newer (and also the original series) Star Wars, Oblivion (First 10 min is what the visitors get to experience), Avatar.

Put on some of those movies, turn it up to 0dB and enjoy. If none of those movies gives you a powerful, thrilling and exciting experience, then its you or your system that is at fault.

 

[North_Sky]

I go to the theaters near me (used to) and I cannot EQ the bass; they won't allow me.
I buy 4K Blu-ray discs and there is no option in the menu setup to EQ the Bass.
In my pre-pro I can tune up individual channel (volume control) and add 6dB to the subwoofer channel. Some they give you a parametric equalizer (Yamaha) to EQ bass frequencies, others a graphic equalizer.

If the managers of movie theaters, the recording mixing engineers of major Hollywood movie studios, and replicators on discs (audio) decided to add extra bass in the low frequencies that is great for us consumers and movie lovers and bass addicted freaks.

But, if they decided (film directors, bla bla bla whoever) to filter the bass for whatever reason (young children, protection of our home structures and cement foundations), then if we are truly serious about it we need machines that will restore anything that was filtered and down to the last drop of a fraction of a Hertz...0.001 Hertz.
We want it all or go home. Science in bass is within our reach, in the palm of our hand ...
Can we do that without a PhD in bass mathematics? Or are we better off spinning LPs?

P.S. With a sense of humor of course.

 

[sigbergaudio]

Since you read Norwegian language, you can find 2 articles on my page about Sub-bass. Part 1 is about what it is - perception, part 2 is about content - what is there. If I had English translations for those, I would have placed links in my previous post, but that does not exist, and a googels-translate is not good enough.

Thank you, I've dived into your very informative library before! Those are indeed interesting articles. My main takeaway then for a home cinema situation is that there are subsonic content in both music and movies that has an audible effect and positive effect if you able to reproduce it. You will however need a pretty competent system (SPL-wise) to reproduce it at a significant/audible level. So if you are unable to reproduce sub-20hz frequencies at 100dB or more (which require quite potent subwoofers), or you simply don't listen that loud, you might as well cut-off higher, reducing distortion and amplifier requirements. Agreed?

 

[Chromatischism]

Sub-20 Hz effects are noticable under 100 dB. I found this to be true with my equipment. I can enable the rumble filter on my Rythmik subs and lose a little impact.

 

[North_Sky]

If a sota system can reproduce one Hertz, why filter stuff below 35 Hertz?
If a low class system can only reproduce 20 Hertz then there's no worries below that.

 

[North_Sky]

How many theaters near where we live can cleanly reproduce 10 Hertz with movies that on average are limited to 25 Hertz?

 

[Kvalsvoll]

Thank you, I've dived into your very informative library before! Those are indeed interesting articles. My main takeaway then for a home cinema situation is that there are subsonic content in both music and movies that has an audible effect and positive effect if you able to reproduce it. You will however need a pretty competent system (SPL-wise) to reproduce it at a significant/audible level. So if you are unable to reproduce sub-20hz frequencies at 100dB or more (which require quite potent subwoofers), or you simply don't listen that loud, you might as well cut-off higher, reducing distortion and amplifier requirements. Agreed?

Yes, this is correct. <20Hz makes no sense unless capacity is quite high, and if you never listen quite loud, you don't need it.

But do not believe it makes no difference. A decent system with sufficient capacity is a very different experience.

 

[sigbergaudio]

Sub-20 Hz effects are noticable under 100 dB. I found this to be true with my equipment. I can enable the rumble filter on my Rythmik subs and lose a little impact.

But do you know at what frequency that filter kicks in? Depending on its frequency and how steep it rolls off, It might start to roll-off even higher than 20hz. But interesting topic. Our subwoofers currently have a high-pass filter configured at 14-15hz, and the not really audible effect but still positive/impactful effect is that by allowing the drivers to hit the lowest notes you can get physical vibrations that adds to the experience. On the flip side, the lowest notes can trigger stuff in your room and create audible noise from things vibrating - so depending on your room it may be good or bad.