That's it, I'm not watching any more movies...

Don't miss any movies. Slap on some headphones.

Tell us more info and we'd be glad to help.... What speakers, AVR, Sub(s) do you have? Whats your crossover settings? Speakers set to small or large?

Where is your sub located? Where is your main listening postion? What is the size of your room? Is it sealed or open to other areas of the house?

I've seen this on cable and don't remember a ton of LFE, and I don't see it discussed much on the "Master Bass in Movies" thread. Maybe try some of the 5-star ones like War of the Worlds, The Hulk, Cloverfield, etc.

BTW the original "The Thing" with Kurt Russell was considerably better .

you have the system, you have the volume control, you have the receiver's sub out setting. It's your room and your ears/backside, so why ask folks here? Try it yourself. If you find posts from people who run XdB hot, it's because they experimented and found what works for them - - their tastes, their system, their room. The sun won't go supernova if you see what happens if you turn up the master volume, or if you turn the subs up a few dB. Boldly go . . .

Accoustic treatment does amazing things! A well thought out room will bring to life any speaker! I've got a home theater thats pretty heavily treated and I'm a firm beleiver that the room itself is more important than the speakers put into it. But you have to experiment to see what works as every room is different. In my case the entire front wall is treated, the side walls are treated from ear level down, and I have floor to ceiling base traps in every corner. I recently had the front wall untreated as I was moving the screen up in order to fit larger speakers underneath and so I played around with it some and without the front wall accoustic obsorption the room was just out of whack with echoes and sounded pretty bad.

Sound behaves in a way most of us are never going to understand enough to really design the perfect acoustic treatment, but there are basic rules you can follow that will get you started. And like all things theater related once you start you'll never stop!

I don't have anything to bring to the table regarding the specs and sound absorbers et al...

 

However, you mention that you 'rented' the movie.  I have found that many BD rentals are lacking in the audio dept.  On top of removing the 'extras' they seem to be skimping on the audio too.  I don't know if it official, or just some randomness that I have come across, however, that may be your issue.  The rental was lacking what you were looking for.

 

On a side note, the family rented Dis/Pix's BRAVE last nite.  When I went to the Maximize option to set up the speakers(they offered 7.1), the back surrounds bled through to the side, but the sub was strong.  The point of the story is, if you have a Dis/Pix movie to test, go to maximize and select the sub when in the audio mode.  You should be able to notice your sub.  

 

My 2.4/yo tvins were amazed by the sound of the sub.

 

When I was testing the speakers, i pointed out each one, and when I got to the sub, they got quiet and put there heads on the couch, then my daughter went around the room like a bloodhound, until she found the subwoofer.  I'm tellin' ya, that was one of the best home theater experiences ever, just watching her.  This is what it all about. 

 

Just my 2%.

Do you have the 'dull' sound on all movie playing ?
I don't quite see your issue, As I only have a low cost Onkyo 606 AMP (90W RMS X 7 ) from 2008. My active sub-woofer is a cheap Yamaha and only 2 book shelf (8" + 1") front spk. When I watched DVD / BD like : Batman -The Dark knight, Transfiguration I & II, all friends in the house were very satisfy. Sound power ( SPL to be exact) is what the HT excitement look for. I just need to dial up the Master volume for overall sensation or the l Sub volume for higher LF when the sound is not filling up the whole living room.

If the preview had sufficient bass for you but not the movie, that is a good clue that the soundtrack was lacking, not your setup. Do you have the BD of Tron Legacy? If so, how is the bass in it?

Regarding rental versions, I thought rental editions should be better by common sense. You think it otherwise, I am now aware of it now. Thanks
I came across some cheap (private) copies DVD 9 of many Hollywood movies US$ 2 . 00 each. Their 5.1 are still quite authentic.
Copies are copies. Why downgrade ?

Get a movie with known bass content if you can't offer comparative measurements with your system would be my suggestion too.

Haven't seen the latest remake but Kurt Russel wasn't in the original either Altho I liked the 82 remake better, too. The 2011 prequel version didn't sound so hot and haven't gone out of my way to see yet...

I stand corrected.

Yes. Do you have friends, office-mates, neighbor whom you can borrow a known good bass / sound DVD / BD disc ? Say, you watch and listen to in the owner's HT system briefly prior to the borrow.
In the way, you may find the weaker part of your AV system - say Interconnect and / or speaker cables too long and unshielded, Sub-woofer quality or NOT switched ON ....
Edited by TLCW - 11/24/12 at 1:13am

You're neither cray nor crazy. A bit enthusiastic perhaps...

Two thoughts.

Have you verified your perceptions with instruments?
Bass is a funny animal, hard to "hear" but easy to "feel." It's not hard to push drivers into harmonic distortion leading to "perception" of bass extension that's not really there. It's also not hard to get bass frequencies to reflect. I'm assuming the theater is in the basement, so the ceiling/floor is the only place the bass can escape? You sense shaking upstairs because there's no reflection to cancel the energy. Downstairs, there is, resulting in your 30Hz mountain (one dimension is 18-20 ft? Seems it is...).

Given your perceptions are verified, have you addressed this specific problem?
Instruments don't lie, and you should be able to measure a difference between the rear row and the front, if your ears tell you it's there. It seems counterintuitive, but the only way to fix this is to absorb some of that excess 30Hz energy. The problem is that you haven't been treating bass range, much less the infrasonic range we're working on here. drunkpenguin has floor-ceiling traps in every corner, while you're hanging fiberglass panels, which only have bass absorption under certain circumstances (and you didn't use them that way).

If you really want to fix you room, so your ears shake as much as the floor above you, read this:
http://andrealbino.wikispaces.com/file/view/Master+Handbook+of+Acoustics+-+5th+Edition+-+F.+Alton+Everest,+Ken+C.+Pohlmann.pdf

Chpt 13 covers your issues, Chpt 12, the remedies. Room dimensions and associated room modes, confirmed by measurement, will tell you were to start. Note that drunkpenguin's corner bass traps likely look like Figure 12-25, but without the plywood, they're broadband traps, not bass traps... it's all about absorbing long wavelengths.

HAve fun,
Frank

I looked up superchunk to be sure we were on the same page. Is this what you have (scroll down)?
http://www.facstaff.bucknell.edu/esantane/movies/Acoustic.html

This link is a perfect example of an absorber problem. He makes floor-ceiling superchunks for 2 rear corners, in addition to significant broadband treatment elsewhere, and he correctly builds them as bass absorbers (note the kraft paper). He shows -3dB below 20Hz, and -5dB for the primary room mode at ~45Hz, yet, he still has a significant bass problem. Note that the 45Hz peak has a harmonic at 90Hz, and it grows with his traps... and the decay curves show that the 45Hz mode is still present, if falling a little faster. The rise below 20Hz that he's damped by 3dB is the same "room gain" I rely on to augment infrasonics, so the primary benefit of his trap would be a negative in my mind.

If I had his room, I'd have addressed the 45Hz peak first, then addressed the residual issues. A simple pair of harmonically-related peaks calls for a tuned bass absorber, which has a far stronger effect on a room mode than other options, as shown in the Everest link from yesterday, page 220, Fig 12-38 and 12-39. This approach yields the same -3dB or so on the peak, but it's reverbration decay is 3x faster...

What I'm suggesting is that you measure your room to identify enough about the bass response problem that an effective solution can be developed. Room modes are likely candidates for problem frequencies, and they respond very well to tuned absorbers. You should recognize Fig 12-40 as a ported, sonotube sub minus the driver - a Helmholtz resonator, by definition. I'd suggest perforated panel or diaphragmatic absorbers for most rooms as they can be integrated into walls, but if you like barrels....

Specifically, I suggest you make a few FR sweeps at several seating positions and see what patterns emerge. Compare the decay curves to see if multiple seats are seeing a common problem. Then let's design an absorber to address that issue, and repeat. until you're happy!

HAve fun,
Frank

PS multiple sub locations will also help, but 1 sub can sound good if the room's right...

Can you please share some data? If rows are consistent, left and right of the theater's axis, then it's likely you're hearing a mode along this axis, usually the lowest frequency if this is the longest dimension. That would indicate a tuned absorber on the front or back wall may be very effective, but until I see data, I won't go farther. Guessing does you a disservice!

HAve fun,
Frank

That thread was very illuminating, even if I skimmed the words and focused on the pictures. If I may summarize...

You build a room in a corner of your basement using an existing basement wall for rear and one side, building stick walls for front and the other side. You then sound isolated the interior with double sheetrock and green glue, and a raised floor. You then pretty much covered interior vertical walls with 3" fiberglass panel absorbers, close mounted to the walls. Not sure I caught the ceiling....

The good news is that those two stick-built walls provide a lot of options, and demonstrate a high level of fabrication capability making a successful outcome far more likely. You do good work.

The bad news is that those two stick walls make reflections asymetrical, and your panels are not effective in the bass frequency range. In addition, I'm always cautious with measurement data that's not real loud. It could be the furnace, or it could be how you set up REW....

There definitely seems to be something going on at 30Hz, corresponding to the long dimension, which has very different surfaces at each end. You've added lots of acoustic treatment, but close against the walls. Can you space them out 6-12" (perhaps at the back wall) to increase LF absorption?

I understand you're altering the IB set up... I'd be interested in data from the new arrangement.

Have you looked for bass escape paths, listened from outside with the door closed? I'm interested in asymetries here, like bass leaking out the RF corner, even when the door's closed. The mic may help locate infrasonic leakage.

Now... how to measure. Reading through REW documentation, they do everything from a sweep, and others suggest that RT approaches are ineffective below 200Hz, favoring waterfalls - sensible for resonances.

I need to play some myself...

HAve fun,
Frank

But you have space on the other side of the walls... at least 2 of them! Let me explain what I mean.

You're working a 30Hz problem. You've been looking at options using panel absorbers, but room size limits how far you can space them away from walls, so let's look at other options
- diaphragmatic absorbers
- Helmholtz resonator
- modified Helmholtz resonator (slats/perf)

The issue is finding one that both fits and has sufficient absorption to make it worthwhile. Slats and perfs both have the disadvantage of needing lots of space behind the panel (roughly 30" for 30Hz) when other parameters are realistic. Diaphragms have the panel mass as an added parameter, allowing you to trade off depth. Helmholtz resonators are more volume-based, so you have the option of locating the resonator cavity outside the room. The downside of Helmholtz is locating them for best effectiveness (high pressure region) and the relatively small effect per unit (need multiples). Slat and perf resonoators are modifications of this, with a lot of depth required at 30Hz, in addition to construction complexity (need precise construction).

That's why I like diaphragmatic absorbers - diaphragm mass can be traded off for device depth, and they're not high-Q devices so more forgiving in practice. They're easily built large enough to be effective, and since they look like a wall, they're unobtrusive (assuming the resonant cavity is on the other side of the wall). The formula is on page 201 of Everest, and the following pages show construction options. I'm seeing 30Hz options like:
- 1/8" glass (1.67 lb/sq ft) with 20" cavity
- 1/2" sheetrock (2.08 lb/sq ft.) with 15" cavity

Beats the heck out of 30-40" depth!

I asked about bass escaping because it's the other possiblity: Reflection + absorption + transmission = 1. We've been talking a lot about reflection and absorption, so I'm just being complete...

The asymmetry is a result of construction. While you have built all sides the same, your rear and left walls are backed by cinderblock, while front and right walls are free-standing. No matter what, the freestanding walls will flex more, and reflect less, especially at very low frequencies. That's all.

Make sense?

HAve fun,
Frank