How loud is loud, how to measure it? Is THX calibration bad for your health?

[audio2920]

I nominate you to do a video, of your home theatre using an audio limiter and several movies. I have nominated you for the weekend to produce a video.

Haha! I wish I could accept!

For copyright, time constraint and logistics reasons I probably shan't I'm afraid. It would be interesting though and I will try it in my studio for a laugh at some point in the future.

I would say, in fairness to your limiter approach, I did once mix a trailer that I had to limit the crap out for YouTube as there wasn't time to do a proper low dynamic mix. Although it was a bit crushed and flat sounding, I played it on a TV and kinda went "huh, that's not as bad as I thought it would be" soooo..... I'm not suggesting this as a workflow for cinema, but I do like the occasional reminder that maybe dynamics aren't as moving as directors and mixers like to pretend.

I didn't mention it in the previous post but a reason a simple limiter *doesn't* work for this use case is the interaction between channels. So -25dBfs might achieve the design goal in mono, in higher channel counts it would need to be keyed or have a floating threshold.

Anyway, I agree some things have gotten a bit silly. I do my best to keep levels sensible in my own work, but that's really all I can do at the moment. Maybe when I retire I'll have the time to pursue getting legislation passed....

 

[Andysu]

Haha! I wish I could accept!

For copyright, time constraint and logistics reasons I probably shan't I'm afraid. It would be interesting though and I will try it in my studio for a laugh at some point in the future.

I would say, in fairness to your limiter approach, I did once mix a trailer that I had to limit the crap out for YouTube as there wasn't time to do a proper low dynamic mix. Although it was a bit crushed and flat sounding, I played it on a TV and kinda went "huh, that's not as bad as I thought it would be" soooo..... I'm not suggesting this as a workflow for cinema, but I do like the occasional reminder that maybe dynamics aren't as moving as directors and mixers like to pretend.

I didn't mention it in the previous post but a reason a simple limiter *doesn't* work for this use case is the interaction between channels. So -25dBfs might achieve the design goal in mono, in higher channel counts it would need to be keyed or have a floating threshold.

Anyway, I agree some things have gotten a bit silly. I do my best to keep levels sensible in my own work, but that's really all I can do at the moment. Maybe when I retire I'll have the time to pursue getting legislation passed....

I do it myself today. Must I do it all myself and others find poorest of excuses. I lost my uncle, my Dad and my Cat, Sooty last year and you seem scared about some silly copyright on movies. on movies. I lost everything last year, Must I do it myself.
So you have an imdb?

 

[audio2920]

I do it myself today. Must I do it all myself and others find poorest of excuses. I lost my uncle, my Dad and my Cat, Sooty last year and you seem scared about some silly copyright on movies. on movies. I lost everything last year, Must I do it myself.

I'm very sorry to hear that. My condolences. :-(

But yes, I'm afraid given how I make my living, it would be high risk for me to start using content without the owner's permission. I already know I wouldn't be able to mix good quality audio in a cinema with a -25dBfs (or lower) per channel limit, so I shan't be risking it for such an endeavour. I am sorry.

Edit: -25dBfs with Dolby "85" line up.

 

[Spkrdctr]

As it is a medical issue, it is highly unlikely that there will be consensus on any data. Remember the COVID19 comments from the experts? However, they all agree that exposed to loud noise is detrimental to your hearing and the definition of "loud" is too loud for our body to handle. That is the point I wanted to pass on to the ASR members.

That's what I have been preaching. But, I think most people just generally ignore my posts. The US Govt standards are too loose. You will damage your hearing if you go strictly by what they say you can have for long duration exposure. I mentioned before that you have to think of it like radiation exposure standards. It took 50 years for the Govt to get it in the ballpark where it needs to be. Many revisions downward had to be made. Early "safe" limits were later found to be very unsafe. Just a quick side note. It is amazing that the early pioneers in radioactive materials carried it around in their pockets! Yikes! That was the original "Hot Pockets" of their day.

 

[Soundmixer]

sound mixers are getting Deafeningly dB offensive.

This is not a sound mixer issue, it is a theater issue. You might want to actually look at the stuff you post. The sound mixers cannot control the volume of your local theater.

 

[Soundmixer]

It is simple. AUDIO LIMITERS have to be mandatory fitted to prevent the mix levels going above 80dB.
dub stages brag they have NC rating of 30 or 25 if that is so why mix at DEAFENING dB levels??? and cinemas brag about their acoustics and must have NC 30 25 rating so why DEAFENING sound polices that odeon are pushing. If all this NC rating is so good then no need for the stupid DEAFENING sound film mixes then, Huh! Huh!

Andy, you do not know what you are talking about. I don't mix at the same level your local theater plays it. Please, understand who controls what instead of just spitting out mindless drivel.

 

[Soundmixer]

There are no THX certified cinemas anymore. Dolby conquered the professional market a while ago. Almost all major chain film theatres are now Dolby certified. Since the 90s the THX certification is only used on consumer systems, like home theatres, cars, etc.

Actually, there are very few Dolby Certified theaters compared to non-Dolby branded ones. Dolby hasn't really conquered anything. They have always been a leader in the commercial theater space. The only chain to actually have Dolby-certified theaters is AMC, and Dolbyonly has 250 worldwide.

THX has 19 branded theaters within 100 miles of my home. They have 16 in Los Angeles country as well. I think they have about 100 branded theaters in America.

 

[Sancus]

Well I drivel until you say what your name is and what IMDB is or are you scared as well?

I want to say once again that I appreciate @Soundmixer and @audio2920's contributions to this forum as they shed light on a part of the audio content industry that we rarely get much insight into.

Stop antagonizing actual professionals who spend their free time educating us.

 

[ernestcarl]

If you can't beat them join them!

True, sometimes it’s fun to go with the flow… If I brought my in-ear attenuators then I probably would have been more tolerant of the situation. But it’s just sooo annoying and distracting to be forced to cover one’s ears while in the middle of watching a show at such seemingly irregular shouting intervals.

 

[abdo123]

Also, it doesn't help that cinema acoustics can be poor, like you say. I wish there'd be more focus on acoustics in [Dolby] cinema spec in the future.



Ouch!!

The rooms are too big to have any room modes in the audible spectrum, how can they be improved acoustically?

 

[audio2920]

I want to say once again that I appreciate @Soundmixer and @audio2920's contributions to this forum

Thanks @Sancus, that's very nice of you.

@Andysu I know this won't change your opinion, but I am sorry about the situation. It's just not appropriate (or worse, contractually allowed) for me to discuss any specific titles.

The rooms are too big to have any room modes in the audible spectrum, how can they be improved acoustically?

You're right, bass response is generally very good in these rooms. It's more things like slap echos and that bug me.

Whereas in small rooms the reflections seem to integrate in to the overall sound and create a sense of space for me, in the big rooms it goes beyond that and I hear specific reflections as a slap back. In the sorta 10-40ms kinda range maybe?

Rooms with a lot of that going on sometimes seem harsh to me, even if they measure correctly with a sweep or MMM.

I wouldn't know how to regulate it in a specification though...!? I guess for that specific issue you'd look at attenuation of the first bounce from each wall, in conjuction with delay? Dunno... haha.

(I'm less worried about long reverb tails themselves, but I guess that's all intertwined.)

 

[abdo123]

Thanks @Sancus, that's very nice of you.

@Andysu I know this won't change your opinion, but I am sorry about the situation. It's just not appropriate (or worse, contractually allowed) for me to discuss any specific titles.



You're right, bass response is generally very good in these rooms. It's more things like slap echos and that bug me.

Whereas in small rooms the reflections seem to integrate in to the overall sound and create a sense of space for me, in the big rooms it goes beyond that and I hear specific reflections as a slap back. In the sorta 10-40ms kinda range maybe?

Rooms with a lot of that going on sometimes seem harsh to me, even if they measure correctly with a sweep or MMM.

I wouldn't know how to regulate it in a specification though...!? I guess for that specific issue you'd look at attenuation of the first bounce from each wall, in conjuction with delay? Dunno... haha.

(I'm less worried about long reverb tails themselves, but I guess that's all intertwined.)

Oh wow sounds like a really shoddy cinema if they haven’t done the bare minimum of treatment. This is far from the norm.

 

[audio2920]

Oh wow sounds like a really shoddy cinema if they haven’t done the bare minimum of treatment. This is far from the norm.

Thankfully, overall, yes!!

They all have reflections of course, it's a question of how much, and of what quality.

I just think maybe now could be a good time to move general room acoustics (in cinema) up the agenda a bit. I think it might help with the whole "too loud" thing, as even after calibration, some really are chalk and cheese. That's all really

 

[MC_RME]

That may be the in-app purchase price. I see no price, nor paid any.
View attachment 173243

You most probably were lucky to get it when it was free. Either it was in the beginning, or is free from time to time (as many apps are). But the price is still 3.99 when I look. I can't download it without paying, and it seems add-ons are also available.

 

[Andysu]

Dolby Leq 737 loudness meter

 

[audio2920]

Dolby Leq 737

Ha.. very good!

 

[Head_Unit]

US Govt standards are too loose...It took 50 years for the Govt to get it in the ballpark where it needs to be.

I was just reading exactly that in National Geographic (04/2021) regarding fine particulate pollution. One study showed increased death or whatever in areas under the supposedly safe limits. (I think the comparison was normally around the limit, versus well below the limit at the start of COVID). Other standards can be too loose:
- The FAA purposely ignores the nature of hearing while for 30 years fighting off making regulations on aircraft overflight noise (which they are supposed to do by Presidential mandate and which should be their goddamn JOB). They keep insisting on one number, which blows over the spectral nature of our hearing, the directional nature of our hearing, and our ability to hear patterns such as helicopter rotor noise.
- The CALM act itself is another example: I had written Anna Eshoo and told her to ignore all the blah blah blah and that the standard should specify a very simple maximum loudness, say - 6 or -10 dBFS. Instead it refers to a bunch of technical stuff and guess what COMMERCIALS ARE STILL TOO LOUD.

 

[Head_Unit]

Andy, you do not know what you are talking about. I don't mix at the same level your local theater plays it. Please, understand who controls what instead of just spitting out mindless drivel.

I think the misunderstanding is the idea that the theater is calibrated and everything plays back as it should, hence you hear what the mixer mixed. BUT
- Once a manager admitted to me they had turned it up due to a matinee with lots of noisy kids expected (I had gone to complain that dialogue was shoutingly loud)
- Another time at the end of a film I asked my buddy "gee it looked out of focus, is it my contact lenses" and he and some others around said no it's off. Went and mentioned up front - "oh that focuses automatically" to which I replied that if everyone sitting around us agreed it's blurry, your automatic focus is off.
Seeing Blade Runner 2049 at the Westwood cinema, we really wondered about this. The bass just seemed to be constantly loud and droning. Rather like a professor I know...

 

[Spkrdctr]

I want to say once again that I appreciate @Soundmixer and @audio2920's contributions to this forum as they shed light on a part of the audio content industry that we rarely get much insight into.

Stop antagonizing actual professionals who spend their free time educating us.

This is ASR, it is all people do all day every day around here. Stopping it would mean closing down the website!

 

[Andysu]

"what we hear there is same thing they hear there"

The audience is still listening...

This was a JBL THX chest pounding throbbing low end of depth when hearing it at the CIC Empire Leicester Square