Re: Sound problems with The Dark Knight

One more thing John, as you know the PS3 decodes everything so no decoding from the receiver. However, when I switch between the Dolby TrueHD soundtrack and the DD 5.1 soundtrack during the movie the DD 5.1 sounds improves the dialog, even the LFE.

John, I know that you have heard both standard and hi res soundtracks. If you wouldn't mind giving it a switch between both soundtracks on the BD version of TDK and telling me what you think. It would help me decide whether to re-calibrate everything. Thank You.

EDIT: It happens during the music and dialog together scenes.

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[Post edited by tony1569 on Dec 20, 2008 - CST 12:47 PM]

Tony,

Give me a timing (start and stop) for a part of the movie's soundtrack that sounds particularly bad to you, and I'll give it a listen.

John

In regard to the robust ("hot," as Ralph Potts called it in his "Official AVS Review") bass output on "The Dark Knight," here are a few casual observations about bass response in general. Bass is probably the hardest part of any sound system to measure for a variety of reasons, which is why it can vary so much from system to system. What's more, people have different tolerances for bass response, some liking more bass, some liking less.

In the first place, deep bass doesn't register on the ear the same way higher frequencies do. The deepest bass notes can usually only be felt and not "heard" at all. If you've ever listened to an actual 10 Hz note being reproduced by a super bass woofer, you'll remember you can only feel it in the pit of your stomach or see the walls and windows rattling. (OK, there are only a handful of bass woofers that can reproduce a 10 Hz note, and they cost a fortune. I was fortunate one time to hear Dave Wilson of Wilson Audio demonstrating his 24-inch subwoofer one time in a $100,000 system.) The 10 Hz note hasn't much sound of its own. For this reason, people often turn their own bass woofers up much louder than the midrange or treble drivers in order for the bass to sound subjectively just as loud. And this relative perception of less bass is exacerbated at lower volume levels. There is even an idealized response curve worked out for it called the Fletcher-Munson curve, which basically suggests how much higher you should adjust the bass than the midrange at lower volume levels. Anyway, the upshot of all this is that many people turn their bass up too high to compensate for the subjectivity of their ears. This is fine until you get a soundtrack like "TDK," which is already pretty hot, and then the bass can be overwhelming.

Next, the room position of a subwoofer affects its output. Put a sub in a corner, and it will increase its output by up to ten or more decibels, which can either be good or bad depending on how much you want it to deliver. Pull the woofer three feet or so from a corner, and the output will decrease dramatically.

What's more, when measuring the output of a subwoofer with a sound level meter, you'll see that the bass response varies considerably depending on where you take the measurement. In my own small listening room, the measurement varies by as much as ten decibels depending on the measurement position, which is why I try to sit in the "sweet spot," the place where I've taken all my measurements for all the speakers, when I watch a movie. We have a two-seater couch in the TV room. When my wife and I watch a movie together, I set on one side, about a foot from the center sweet spot, and the bass increases by three-to-four decibels. If I were to sit in the far corner of the room, the bass would be some ten decibels higher. Obviously, it sounds boomy in a corner.

On top of all that, every different brand and model of bass woofer has different output characteristics. Not only do some bass woofers reproduce lower notes better than others (a good woofer should go down to at least 30 Hz for optimum results because that's about the lower limit on most movie soundtracks), and cost more, understandably, some woofers also have better control of bass overhang (damping) than others. Overhang is the amount of time it takes the woofer cone to come back to rest after reproducing a bass note. The longer the cone takes to stop vibrating, the more it will interfere with the clean listening of midrange frequencies. For this reason, I have audiophile friends who will not use a bass woofer at all, because for them any bass, and especially a long bass overhang time, tends to obscure the clarity of the mids, and midrange transparency is, for them, the ultimate in sound reproduction.

And I haven't even touched on the woofer's linearity and its crossover points. Linearity refers to a speaker's ability to reproduce all the frequencies within its spectrum at approximately the same level. For instance, in less-competent subwoofers, ones that won't go down very deep, the manufacturer will often build in a mid-bass bump, say between 60-80 Hz, to impress listeners with its bass output. Bad.

Also, the woofer should be matched to the lower ranges of your other speakers by setting its crossover properly. THX recommends an 80 Hz crossover because most smaller speakers (for the sides and rear, mainly) don't go much lower than that, and the woofer can handle most frequencies below the crossover point. How linear your subwoofer is and where you set the crossover can also affect the resultant sound.

So, for best bass, you need to start with a good subwoofer, one that goes down deep, reproduces cleanly (less overhang the better), and is fairly flat in reproducing all bass notes from 120 Hz down at approximately the same output level (and that usually means a good deal of money). You need to take all your speaker measurements from the optimum listening position (usually dead center with the TV, with the left and right speakers an equal distance apart as you are from them, the surrounds at the sides and/or rear, and the woofer wherever it provides the best response). And you need to be sure to sit in the optimum listening position (where you took the measurements) for optimum listening pleasure.

Or not.

As for differences in lossy Dolby Digital and lossless TrueHD or DTS-Master Audio, one of the differences I often hear is greater smoothness in the lossless codecs. Regular Dolby Digital usually sounds brighter and edgier to me in the mids and highs. However, "brighter" can also seem like clearer sound (especially if a listener's speakers are somewhat dull sounding or recessed to begin with, and the listener's bass response is already overly prominent). For some listeners on some systems, the brighter midrange sound of Dolby Digital can better bring their speakers to life or cut through their bass overhang and be heard more clearly. This doesn't make regular Dolby Digital actually better in any absolute sense, but it can be subjectively "better," which is all that will count for some people. So, there are no easy answers, and lossless audio may not be "better" for everyone.

John

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[Post edited by John J. Puccio on Dec 20, 2008 - CST 2:01 PM]

Thank you John! Your sound adjustment method was not all that dissimilar from my own.

Onkyo owners, Your Audessey mic is fairly accurate, but you will need to bump a few levels here and there. Calibration is everything for some of the more elaborate sound mixes. Most studios put a basic DD5.1 mixdown on most releases, that really does not even showcase what the original score had on film.

Reaggie,

That's true. Studios adjust movie soundtracks for home DVD/BD playback. However, as for the actual mixes, almost all modern movies are engineered for 5.1 playback in theaters.

John

Great explanation on sound John!


My advice is far more simple. For this movie, and any others with wide dynamic range, just go over to your sub and turn the knob back until it suits you.

Yeah, that'll work, too.

Unless you've got a subwoofer like mine with the volume control on the back, and lost amid a number of other knobs and dials.

John

Ok first let me say great detailed explanation John. When I first got my ONKYO you and Reaggie gave great advice. The sub is in some what of a corner. John, because I made some adjustments the movie dialog sounds better but what I wanted you to hear was the difference between DTHD and DD 5.1 one scene in particular was the whole Harvey Dent police transport scene. Reaggie, you as well try it out.

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[Post edited by tony1569 on Dec 20, 2008 - CST 6:51 PM]

tony,
i know i wasn't asked.. ..but iv'e watched this scene atleast 20 times. the sound is indeed a "rollercoaster ride", which imo, gives it a dynamic punch. it sounds exactly how it did in the theater for better or worse. i like the sound design myself. but, there is nothing wrong with your system, unless you just have it turned up too loud. and you don't need to re-calibrate just for this one movie.

getting back to the scene you mentioned. it is VERY powerfull,(dynamic punch!) and what you percieve to be audio dropouts are indeed very low bass frequencies that as john mentioned above you should be "feeling" more than "hearing".

OK, Tony, I did as you suggested. I watched the extended IMAX sequence from 1:14:25 to 1:23:00, chapters 20 and 21. I kept my eyes closed most of the time as I made comparisons between the Dolby Digital and Dolby TrueHD, opening my eyes for a second now and then only to change the audio streams, with the main language menu on screen.

I found the Dolby Digital slightly edgier, sharper in contours, and thinner than the TrueHD, making surround activity sound more localized from individual speakers.

The TrueHD sounded smoother overall, rounder, and weightier, with a more seamless surround field around the room.

In both cases I heard tremendous dynamics, impact, and bass, yet I was able to hear the dialogue clearly and easily. Nothing was muffled or overpowered by the low-frequency effects. However, as I said earlier, I can see how the brighter Dolby Digital track could make dialogue easier to discern on some systems.

PS: I liked the sequence so much, I watched through it a second time entirely in TrueHD with my eyes open and the offending menu screen gone.

John

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[Post edited by John J. Puccio on Dec 20, 2008 - CST 7:28 PM]