The LFE test

Discussion in 'Speakers & Subwoofers' started by andySu, Jul 15, 2006.

  1. andySu

    andySu Cinematographer

    Apr 7, 2006
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    Quite some time back I did a rather exhausting test called “The LFE Test” what I was looking for was the highest peak level in the LFE regardless of frequency response, what I found was that “Star Wars Episode 2 Attack of the Clones” had the highest peak measuring at (0dbvu).

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    Films with that big shaking rumble in the tummy abyssal depths of low end with almost unrelenting pressure….

    The L.F.E Low Frequency Effects, over the years the L.F.E as provided some fantastic effects to the on screen action, if not more for taking on some with high dynamics that get most home cinema users reaching for the sub bass volume before it has been driven to the point of Armageddon?

    So with this thread, I’ll be looking at the films that have highest range along with the frequency response, looking at the response on a VU meter which controls the flow of sub bass and L.F.E on a multi-channel audio mixer, I’ve set the AVR Kenwood KRF-X9050D THX select to 0db and using the DTS calibrating disc to align the inputs and outputs from all RCA phones.

    The reason for this is clear EQ as to be apply to the whole program set-up to get smother timber balance of the fronts and the split-surrounds and some other channels too, like the centre back and the upper centre channel, but I’m not hear to give a total discussion on that the goal hear is to explore the L.F.E.

    First I’ll start of with, Star Wars Episode 4 A New Hope.

    Well this was a whole of fun, so hears my report.

    Opening the star destroyer rocketing overheard with the LFE, adding the extension to the scene and giving the wow feeling responding from 25Hz though to 40hz and 60hz with 25Hz having the highest peak, but this doest overpower nor spoils with too much.

    Less is more, because as the film continues to play on the LFE will get big with its dynamics with what is presented on the screen, so playing at 98dbc @1m and giving me an accurate response on the films playback is satisfactory.

    I’ve gone though the whole film note the time and the SPL level against frequency response on the RTA as well, the results so me that its better and wiser to keep to the technical tolerances of the THX sound system operational parameters.

    At 56mins the death star destroying the planet with a devastating huge explosion 105dbc @1m and peaking at 25Hz 40hz slightly less and 62Hz all adding to the feel and the awesome power that this planet destroyer can unleash.

    With lots of LFE effects playing at randomized times throughout the destruction of the death star coming in at 107dbc @1 topping of the film the wave of low frequency air pressure swooping down from 40Hz and climbing upwards to 25hz as it gently presses on me, I’m happy this as played well the JBL 4645 THX professional cinema sub bass unit can easily peak @ 120db but I’ll keep this to a realistic cinema level, while the fronts and the split-surround-EX can also measure up to the same level.

    The next film I’ll be looking at will be Superman the Movie, and leaving the levels and settings as they are I’ll be very impressed with its mighty powerful mix LFE style that’s going to blow me away, I wish….
    So with the opening of “Superman The Movie” the score by John Williams gives the power of this classic film slam on the LFE at 1m 48s there is a huge slam at 100db @1m with peak at 40Hz (-7dbvu) the style of the opening is one of openness.

    The highest peak in the film or peaks, when Krypton explodes with a devastating KABOOM, coming in at 21m 40s 109db (-3dbvu) frequency 25hz third in the scale 40Hz being the first 62Hz being the last peak, the JBL 4645 handled it without no strain or popping.

    When one of the rockets reach there target, with the impact coming in at 109db (-3dbvu)
    40Hz with most random LFE effects at 2h 2m 10s 100db and 106db (-5dbvu) when lightning strikes the air-force one KABOOM.

    When Superman pushes the huge rock over to block the path of thousands of tons of water comes crashing towards a small town, the rock kicks at a small 91db 2h 9m 7s and climbs up to 105db (-4dbvu)

    With the closing credits rolling the LFE is neutral with just the bass from the three-screen and the split-surrounds in there EX mode.

    So what’s next “Apocalypse Now” is a long film and with two versions of it to test, this will take two days to complete this.

    In my written notes there is a whole lot more, and it was trying and taxing too, do I what to really do this again yes, its fun.

    1# Master and Commander with peaks at (0dbvu) and down to 25Hz the aggressive cannon firing at the opening so far I haven’t seen a film that surpasses it.

    2 # The Lord of the Rings part 2, with peaks at (-2dbvu) down 40Hz, there is huge explosion when the castles walls are breeched.

    3 # I’ Robot (-2dbvu) peaks at 25Hz, the opening dream sequence, showing “Spooner” being saved by a robot, the score by “Marco Belrami” as lots of low end but short of “Master and Commander.”

    4 # Star Wars Episode 4 A New Hope (-2dbvu) down to 25Hz the Death Star, as it unleashes it devastating power, and utterly destroying “Alderann.”

    5 # “Superman The Movie” (-3dbvu) down to 25Hz, Krypton explodes due to there own star in the galaxy KABOOM!

    6 # “U.S Marshals” (-18dbvu) down to 40Hz, with very little happen on the so called (SVS) plane crash scene, but still entertaining throughout.

    I’ll have to give, “The Fugitive” another go, to see if the fright-train scene is higher in the LFE department?

    With “The Lord of the Rings” only partly analysed due to the running time it’s the peaks that I’m looking at on the LFE and not sending the loudspeakers to small, sending the loudspeakers to small creates confusion with the LFE issue.

    With these films playing on the JBL 4645 THX cinema approved sub bass, it difficult to find a film that it’s not going to like, and since I’ve gone though some power house films so far with no signs of distortion or popping sound, I’m confident in its performance.

    So with “U.S. Marshals” at 6 # that will drop like a fright-train?

    Well after going though more of this LFE testing, and a simple case of just finding one that exceeds the previous one, well I’ve found more in the 700 DVD’s.

    This is an ongoing quest; still I haven’t got to some of your favourites yet, the ones that push the limits and bounders further.

    So if some of you have any that seam likely of going pass “Fight Club”, “Flight of the Phoenix” or “Master and Commander”, then I like to hear what they are, as for the film, “U.S Marshals” I was saw this was going to drop like a plane!

    So hear this weeks, crème de la crème LFE films, so far.

    1# Fight Club hard edge hitting LFE in this white knuckle, film about a guy that likes mischief and mayhem, so on chapter 9 when the airliner collides in mid air with another aircraft KABOOM the sudden LFE level, rise’s to (0dbvu) down at 25Hz @1m 111db frequency down to 25Hz.

    2# “Flight of the Phoenix” with 12 survivors and no Monkey to be seen anywhere in this remake of the 1960’s classic, the plane crash scene as defiantly got my attention, with some incredible LFE range throwing everything into the mix, including the kitchen sink as well, this is in at number 2 this week on the LFE test. With LFE coming in at (-1dbvu) 112db 14mins 59secs frequency down to 25Hz with some peaks at 40Hz to 62Hz mostly at 25Hz.

    3# “Master and Commander” with cannon firing left right and centre this is a jolly ole sea film, “Down all, hands down!” With LFE coming in at (-5dbvu) down at 25Hz @1m 108db frequency down to 25Hz.

    4# “The Lord of the Rings The Two Towers” magical effects with four hobbits a wizard and some very nasty uninvited guests, that like to crash in on the castle, with a huge KABOOM with LFE coming in at (-2dbvu) down at 40Hz @1m 110db frequency down to 25Hz with average peaks at 40Hz.

    5# “Darkness Falls” This will if not will scare the pants of you in some parts, as a vengeful tooth fairy goes on the nightly rampage, so stay in the light….with the LFE reaching peak level towards the end so watch these levels this one will jump up and will bite you in the @ss! With LFE coming in at (-4dbvu) 109db frequency down to 25Hz.

    6# “Star Wars Episode 4 A New Hope” this film needs no introduction, the Force is strong with this film, with the total destruction of “Alderaan” and the Death Star all going KABOOM at the victorious ending, with LFE coming in at (-3dbvu) @ 1m110db frequency down to 25Hz.

    7# “Superman The Movie” the comic book comes to the big screen, with terrific visual effects that makes you believe a man can fly! Krypton explodes due to there own star in the galaxy KABOOM! With LFE coming in at (-3dbvu) down to 25Hz @ 1m 109db frequency down to 25Hz.

    8# Terminator 3 The stakes are now raised higher, with the dawn of the machines rising, and the fight for the future the war as now began, with some menacing visual effects, accompanied by some apoplectic LFE when it is called for everything on this one goes KABOOM! With LFE coming in at (-5dbvu) 108db frequency down to 25Hz.

    9# I, Robot in the not too distant future every home will have an NS-5 robot, but for one that saw it coming, but for “Spooner” he thinks differently, with some wild visual effects and sound design, this will have the room shaking, the opening along is dynamic enough, with LFE coming in at(-7dbvu) down at 25Hz @1m 108 frequency down to 25Hz.

    10# “Alien VS Predator” Guaranteed that nearly everyone dies horribly at the hands of an ugly son of a b!tch or some drooling slimy Alien, this is a no mans land, and I’m voting for the Predator, with caverns and solid walls and lots of LFE from start to finish. With LFE coming in at (-5dbvu) 108db frequency down to 25Hz.

    11# The Fugitive Harrison Ford is on the run with Tommy Lee Jones in pursuit, Ford is looking for the one armed man? And with a train wreck of carnage left behind him the chase is on, with LFE coming in at (-7dbvu) down at 40Hz @1m 108db frequency down to 40Hz with very little at 25Hz.

    12# U.S. Marshals Tommy Lee Jones is now in pursuit again, this time Wesley Snipes is on the run to prove he his innocent, with a major clean up of wreckage of airplane left all over the road, this chase is on again. With LFE coming in at

    (-18dbvu) down at 40Hz @1m 102db frequency down to 40Hz with not much happening down at 25Hz, but it there, just not totally dynamic enough, as I was told it was?

    “Did you find out what you wanted to know doctor?”

    Well this was just under most of want I have tested so far, in terms of db and sound pressure levels.

    With the opening in a relaxed kinder of mood setting, setting the tone for this chillier thriller, let me point out the split-surrounds with the centre back surround enveloping myself with a soft 85dbc slow weighting and gradually climbs upwards to 88dbc slow weighting.

    I then check the LFE and it was a lower deeper sound pressure down at with 40Hz being the first peak level and 62Hz at second peak level and 25Hz at third peak level, but things are soon to change!

    Chapter 10 107db (-7dbvu) 36mins 34secs the huge thumping sound at the bedroom door with moderate aggressiveness, with a second thumbing sound, coming in at (-5dbvu) down at with 40Hz peak in 1st 25Hz in 2nd and 62Hz in 3rd order, its now that I realise this mix isn’t going to go that low in the LFE channel, like most I have tested had peaks at 25Hz, but still it registers on the mix.

    With the closing battle between Eleanor and Hill-Crane the monstrous demon that wont let the souls of the children leave the house, the showdown with the LFE was fitting enough, while note on the spectrum analyzers for all the channels on my home cinema set-up the fronts where packing some low end usage in the mix registering down to 25Hz 40Hz 62Hz with peaks in the 40Hz range, but the blending of the other channels low frequency extension was turned off via the mixer, as I wanted to check the LFE out carefully.

    So its said that re-recording mixers always like to leave the largest sound the thunderclap sound to last, has Hill-Crane is slammed into the doors with a huge 108db SPL slow weighting (-7dbvu) 25Hz 2nd 40Hz 1st 62Hz 3rd in that order, a fitting end was Jerry Goldsmith’s score “Hail Jerry” to the late film score composer no longer with us, I shall miss is works…….

    The LFE should never be allowed to overwhelm the wholeness of the film, instead it should mealy reinforce the soundtrack on Dolby dts and SDDS motion picture soundtracks, this is why I think if any one can try to understand my findings and know that I’m looking for the one part within most of the 700 films I currently have on DVD and a few on Laserdisc with high bit rate dts, this is thread is only for some that don’t what to keep getting up all the time and turning the sub bass volume down due to small sized models that most people buy.

    Not all films have the aggressive LFE, no there is this common belief that all films do, well after going though some 14 films now with “Strange Days” being added to the LFE hall of fame, so to speck there is only a few parts in the film where the LFE as resisted at (-5bdvu) frequency down at with peaks in this order 25Hz 3rd 40Hz 1st and 62Hz 2nd 108db SPL chapter 1 time 3min 55sec, this when one of the crocks jumps from the roof top to the opposite side where his partner is, this as realistic “POV” approach, with gunfire being disorienting, as a viewer I find myself looking all around myself believing I’m there via sound only, has with my peripheral vision seeing all that is around me it still entertaining.

    Has the guy falls the peak level then registers at (-6dbvu) with frequency down at 25Hz 3rd 40Hz 1st and 62Hz 2nd at 107db SPL as the frequency on the LFE is higher in some parts, then the output from the sub bass loudspeaker will be higher due to wave lengths, but this can all be addressed with EQ if it gets to far out of hand.

    With most all the bass in the three-screen channels and the split-surrounds, on this mix don’t think for one moment all the bass you feel coming from the LFE is LFE bass, its not unless you have your loudspeakers set to large, you’ll never tell which is which.

    Has far as the EQ goes at the present time being, its fine and the JBL 4645 professional is playing back the LFE mix has it was intended to be, like I said earlier in my first post “less is more”, and its seams more universally standardised now, without the need to keep adjusting it every single time there’s an explosion or any type of effect, with “Fight Club” still holding with the highest peak level at (0dbvu), its safe knowing it won’t go over the (0db) reference level, until something else comes by my way, where the fader level will be adjusted accordantly to weigh the differences and keep them in the safe zone of (0db).

    I feel the need, the need for speed….

    What an opening to this film realised in 1986 this action adventure, with its incredible Arial photography and piratical work, so it’s down to the LFE testing now.

    Well this came close to 0db but only really coming in at (-6dbvu) during chapter 11 where the F-14 fly’s into what is called a jet-wash cursing the aircraft to go into a flat-spin, this one of the disorienting scenes in the film, with the swoosh of air rushing forwards and backwards in the sound field, and the LFE accompanying the mains and split-surrounds-EX with threatening realistically low, lows which where giving me ----Goosebumps- as I’m watching the frequency response changing at random intervals going from 25Hz 2nd 40Hz 1st and 62Hz 3rd and then at 25 Hz 1st 40Hz 2nd 62Hz 3rd with (-6dbvu) and as the canopy is ejected via explosive bolts, the force of the frequencies at 105db SPL where pressing on me, whilst being close to ripping up the floorboards, at the same time….

    It’s no surprise to me now, that thinking the thunderclap sound would used towards the end well, with the afterburners effect on the LFE reinforces the films mix with authority down to 25Hz when the occasion calls for its need to give a good sending of to this classic high octane adventure….

    Lucasfilm THX really gives this mix the flexibility, of a fuller octave to octave and no strain within the, tolerance settings of the home THX sound system, indispensable leistering…

    The Italian Job, slick with fast action scenes, stylishly done from start to finish with a twist to it.

    The mix on this one was quieter than most that I have come to knowing, but it’s the way the mixers intended to be, and when some loud moments do come into play, like the first heist, a gold heist, which takes place, “the Italian job” with a safe landing right into the hands of the gang pulling of this elaborate scam with computers and smart thinking, moving onwards when the crew is betrayed by one of the own, and after a shootout and with Steve played by Edward Norton believing there all dead at the bottom of a river lake.

    One year one Charlie Croker” played by Mark Wahilberg, is going to turn things around and to get even and get back the gangs gold, with additional help from “stella Bridger” played by Charlize Theron as safe cracker, the gangs all assembled and there out to get all back……..

    With a down safe come in at chapter 3, 10m 49s (-7dbvu) 25Hz 2nd 40Hz 1st 62Hz 3rd SPL 105db

    Flying-boat coming in at chapter 4, 13m 04s (-15bdvu) 25Hz 2nd 40Hz 1st 62Hz 3rd 25Hz 1st 40Hz 2nd 62Hz 3rd, SPL 99db

    The demolition site coming in at chapter 10, 1h 3m 14s (-15dbvu) 25Hz 2nd 40Hz 1st 62Hz 3rd SPL 99db

    Heavy truck load passing by coming in at chapter 13, 1h 23m 02s (-18dbvu) 25Hz 2nd 40Hz 1st 62Hz 3rd SPL 98.5db

    What where’s what the f**k just happened to my truck?! Coming in at chapter 13

    (1h 24m 32s) (-7dbvu) this a random of low frequencies on the LFE, 25Hz1st 40Hz 1st 62Hz 2nd / 25Hz 1st 40Hz 2nd 62Hz 3rd / 25Hz 2nd 40Hz 1st 62Hz 3rd 25Hz 2nd 40Hz 1st 62Hz 3rd, with the explosion lasting a few seconds long and ending at (1h 25m 47s)

    Well there’s another job done, and checking the LFE out on this one had lees than I thought it had, well not all films carry LFE and less is more, and when used artistically and sparingly it comes to be a surprise….

    There you have, job well done.
  2. BrianTwig

    BrianTwig Second Unit

    May 1, 2006
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    With LOTR The Two Towers I always read about the Helms Deep battle and the breaching of the wall for great LFE. But I never see anyone writing about TreeBeard and the LFE produced by his walking. Why is that? Some of the most intense, house rattling bass I have ever heard in a movie.
  3. Reginald Trent

    Reginald Trent Screenwriter

    Feb 18, 2000
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    Thanks for posting your results, are you gonna test War of The Worlds?
  4. andySu

    andySu Cinematographer

    Apr 7, 2006
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    Yeah, but just be careful has the LFE.1 can be very unpredictable and a sudden output would knacker your sub bass!

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