Subs used in Theaters.... (1 Viewer)

[Jon Best]

I was just reading the thread about the 19 year old guy who at first hated his SVS and then blew up his amp. I noticed where a few guys who know a good amount about bass/subs suggest he buy a few pro JBL subs and this made me remember something I had been thinknig about. The newest THX theaters use JBL or Klipsch speakers often (I'm pretty sure they do at least) If you look up this equipment on JBL'sa pro sound site it says they only play down to 30-40Hz, Are these what is being used in theaters ? Doesn't THX require them to play down to 20 or 25Hz? If thats all thats needed in theaters than why do we need HT subs to go below 20Hz as giving them the ability to do this must sacrifice some of their abililty to play at higher levels.
Just curious.....

 

[RichardH]

I think the primary reason for the low bass rolloff in the theaters is to avoid bass leaking into adjacent theaters. It's still a problem at some places, though. You're in a quiet passage, and the movie next door is an action flick; you can feel the explosions.

Plus, it's that much harder to pressurize all that space; doing it down to 25Hz would be very expensive.

 

[Mark Seaton]

It is a problem for most subwoofers used to produce much bass below the standard THX required 35Hz in these size theaters. This is the only reason for the lack of low end. Of course there are always solutions, it is a matter of awareness and willingness to invest in such a capability. A few primiers of movies have brought in BassTech7s (solid to ~28Hz or so) to do the job and have never recieved anything but high praise. Someone just needs to realize that moviegoers might really appreciate honest deep bass.

 

[Jon Best]

Is there sub 30Hz sound on movie soundtracks?
I'll say I've never been disapointed in the sound/bass in any of the first class theatres (Stadium seating, THX, etc) Actually I prefer the movie experience at the theater to that of a HT. Not to say that a pefectly setup HT system consisting of high end equipment cannot equal or better that of a theater, I just have not heard it yet.

 

[Dustin B]

You must have some nice theaters where you are. My sound is vastly better than my local theaters. And if I do manage a projecter soon my picture will be as big (relatively) and look as good if not better too.

Our theaters suck, no leg room, no stadium seating, harsh poorly calibrated sound and the picture isn't that great either.

 

[Cam S]

Hey Dustin, When I was in Saskatoon I watched the movie "The Signs" at the movie theater right by the Midtown Plaza mall. I thought that theater sounded pretty dam good. I wasn't too sure if it was THX certified, as I asked one of the workers there and they didn't even know what the hell THX was! The theaters provide a different atmosphere along with the movie, and I enjoy that part. Watching Lord of The Rings in the theater is just awesome, though my system can go louder it just doesn't feel the same. I sure would love to see theaters capable or producing the sub 20hz bass notes that my Shiva can produce, man would that make it so much better. I actually wouldn't mind paying 10 bucks a movie for that kinda sound

 

[Antonio_B]

Hey all,how are you?
Well i went to see movies in many theatres until now.I noticed that every theatre has its stong points and weak points.In one of them,the dialogue was soo crystal clear that you would say the person talking was just in front of you, but its weak point was that it lacked some deep bass.
In another theatre,the dialogue was not very clear ,but the bass was not missing at all....I swear the seats were shaking the whole movie;i felt that extreme pressure filling the room.

Well,after all,we can conclude that it all depends on the budget invested in the equipments.
But IMHO,i think that you cannot reproduce the atmosphere felt at the local theatres.Just look how big the screen is......

 

[Jon Best]

They recently updated the local "mega theater" close to me and it has 15 Theaters all with stadium seating, huge screen and THX.
I agree that in a HT you can make the sound effects more noticeable as you control the volume and your much closer to all speakers. But I agree theres nothing like being in a huge room with a 40' widescreen and a THX approved sound system, as long as it's not packed.
I'd bet a $100,000 HT with all of the trimmings may be better though

 

[Jon Best]

www.hps4000.com
This is an interesting site. This system is suposed to be close to the best, I don't know if it's outdated though. The surrounds look like the could work well in a HT, They will sell to the public also.

 

[Zack_R]

I was wondering about theater bass sound, too. It's like Dolby Digital is making the requirements for accurate sound more stringent for home theaters than movie theaters.

How many movie theaters can reproduce 115 db freq. @ 20 hz. from any given seat? The way bass works this would mean you'd have maybe 125 db at other seats just so you could reach the minimum level at the weakest seat. Knowing how big most theaters are and how far away people sit, it would take an enormous amount of power and multiple drivers to throw out that kind of volume.

Even theaters with woofers producing 35 hz frequencies, are they hitting 115 db at any given seat? I know movie theaters are pretty loud, I guess I'm wondering if anyone has taken a sound meter along just to see how loud they actually are.

 

[John F. Palacio]

Even theaters with woofers producing 35 hz frequencies, are they hitting 115 db at any given seat? I know movie theaters are pretty loud, I guess I'm wondering if anyone has taken a sound meter along just to see how loud they actually are.

This is a most interesting question, Zack. I don't know if it has ever been asked, let alone answered.

As you well state if the "reference" levels are at *ANY* seat then what will they be at the seat/s nearest the speaker?

I am sure this had to come up during the drawing of the specs.

 

[Dustin B]

IMHO,i think that you cannot reproduce the atmosphere felt at the local theatres

And I think that is where we really differ. I wouldn't want to reproduce that atmosphere even if I could. Loud kids, annoying people, annoying people that talk through the movie, cell phones, people munching on all sorts of candy (some foul smelling).

Not to mention sticky floors (I wouldn't mind it as much if our theaters had stadium seating, with decent seats and decent leg room, but they don't).

When I get a projector I'll have a 7-8' wide screen being viewed from a little over 14'. Not to far of the videophile ideal of your viewing distance being 1.5x the screen width.

I'm not sure if you are talking about the Center (worst seating ever) or Pacific cinemas Cam. Pacific theater 4 is definately the best theater in the city, but I was wincing during Lord of the Rings in some parts because the high end was so harsh. Never once winced when i watched it on my system, flinched a few times, but never winced because the sound hurt my ears.

 

[Khoa Tran]

The theaters around me (Irvine Spectrum 21 & AMC 30) are great i watched LOTR in the JBL THX and man that place rocked!, oh yeah all the theaters without Stadium seating and Dolby Digital closed down around here, it's more like a standard where i live....

 

[John F. Palacio]

I wouldn't want to reproduce that atmosphere even if I could. Loud kids, annoying people, annoying people that talk through the movie, cell phones, people munching on all sorts of candy (some foul smelling).

I'll second that!!!!!!!

 

[Antonio_B]

Well dude i was not talking about the ambient atmosphere like you said Dustin(people talking,sticky floor and all that..) but instead the actual performance of the components.
BTW,i live downtown Montreal and we have one of the best theatres in the country(Famous Players and AMC Cinemas).

 

[Shawn Solar]

I thought movie theatre's had compressed audio tracks. Something like 88db-90db peaks. could be wrong.

 

[Cam S]

Dustin, the theater was right outside the Midtown Plaza mall. I remember a bust of Ghandi right on the corner beside the theater and a Subway there too. Not sure if there are more than one theater on that street though. I do remember taking an escalator to get up to the theaters, man I love escalators, haha.

 

[ChrisWiggles]

The volume DOES change significantly, depending on where you are in the theater. In the Cinerama here in Seattle, which has a HUGE screen, and DLP projection to boot, along with a THX sound system, the trick is to get as far from the screen. I watched 2001, and I was sitting close, which was ok because it was film, so there was no screen door effect if it had been DLP, but it was too loud so close. I made that mistake again with EP I, which they were using DLP that time, and the pixels were very noticeable, and it was unpleasantly loud. The bass kicked though, but not extra-deep. I don't think it would be possible to get 20 hz that loud in a theater as big as a Cinerama.

Anyway, I went back to see the second LOTR, and I did not make the mistake of sitting up close. I sat far back, and the HUGE screen was still more than big enough, the bass still rocked, and the volume was much better, not nearly as loud and harsh as it was up close. I think a well-done HT easily outperforms a pro theater, except in the video department. That costs big $$, but audio can be done well with just a few grand, that easily outperforms the best.

 

[Cam S]

The only real reason why our home systems are better than then the theater systems (besides outright sound quality) is because our home theaters are in a MUCH smaller room. Put our HT speakers in a theater and they would really suck. Now if only theaters could use the kind of speakers like what we use in our homes, just more of them. Could you imagine 5 or more SVS B4-plus subs in the theater, man would that be nice.

 

[Dustin B]

Whoops, I go to the theaters here so infrequently I got a couple mixed up. I didn't mean Center, I meant Capitol 4 and that would be the one you went to. Pacific is like 3 blocks from the Capitol 4. Had a very bad viewing of Harry Potter at the Capitol 4.