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Author Topic: The LFE test…. Andy Summers Master Film Handler Posts: 397 From: Bournemouth Dorset United kingdom Registered: Jun 2005 posted 08-13-2005 06:29 PM                 Introduction 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 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 if you have any films, that you will like me to cheek out there is a 99.999 probability that I will have that film. And using the techniques though they may not be new, it’s the level of the testing to show that less is more on the LFE rather having the levels set to the point where it’s masking all the other channels. The VU meter display showing me the wholeness of the LFE from -20db to 0db, and setting the THX peak management level to 0db, and performing a peak level test with the THX sub bass output displaying the rawness, setting the SPL meter @1m from the JBL 4645 where I align the sub, with sub bass random pink noise from the DTS calibration disc and setting the level to 70db instead of 75db due to the sensitivity of the JBL 4645 which as a newer sub bass driver in the enclosure. I’m also aware of the 85db industrial setting but due to the size of the room, this all fits into place nicely without giving it to much boom?  |  IP: Logged Mark Lensenmayer Phenomenal Film Handler Posts: 1605 From: Upper Arlington, OH Registered: Sep 1999 posted 08-13-2005 09:05 PM                     Andy, I don't totally understand what you are trying to do. It sounds to me like you are looking for films that have exceptional LFE mixed in as a part of the overall track. Am I correct on that? About the only thing I would run at those levels is the Brian Setzer Orchestra in Japan disk. (I have a thing for big bands. And I have heard that band live, and they really play that loud!) Back in the laserdisc days, the reputed most powerful film was APOCALYPSE NOW. The Arc Light scene was supposed to be difficult for any but the best systems to play properly. I would also guess that CLOSE ENCOUNTERS during the mother ship scene is somewhat impressive. JURASSIC PARK would also be something to consider. Doesn't the home THX standard call for a calibration at 75dB, not 85? THX Home Calibration Method  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 08-14-2005 12:05 AM                        Why can't people just call it a "subwoofer" like the rest of the planet? "LFE" sounds so home-theater-ish, and "home theater" means "amateur".  |  IP: Logged Andy Summers Master Film Handler Posts: 397 From: Bournemouth Dorset United kingdom Registered: Jun 2005 posted 08-14-2005 12:46 PM                 Mark, You are correct, that is exactly what I’m doing there have been so many people doing the same thing in the past, and the strength of the dynamics on the LFE from past to present showing that it can be damage goods on most peoples home cinema, including the cinema as well. Joe, If I can remember that is what Dolby Labs christened it when Dolby Digital came about. Or I can call it the (Baby Boom) track instead. Mark I have Apocalypse Now, Close Encounters of the Third kind and Jurassic Park on DVD as for Brian Setzer Orchestra in Japan disk, I’ll have to do some research cheeking up on that one, sounds like fun. By the way I’m still running two Pioneer Laserdisc players the CLD-1750 and the CLD-2950 both PAL and NTSC. So I’ll be getting on with Superman the Movie in a short while, know the film backwards it won’t take long to go though it noting the point where the LFE comes in the frequency response range maximum SPL db @1m, as well as the 0db reference point on the VU meter of the mixer. Note the opening on Star Wars Episode 4 A New Hope the thundering star destroyer is loud on the split-surrounds-EX mode reaching 105dbc weighting all most matching the belly shaking LFE. I’ll be back later, and if I have the time I might do Apocalypse Now or the Redux-version, maybe Close Encounters of the Third kind. Bye, bye.  |  IP: Logged Robert Harrison Expert Film Handler Posts: 239 From: Harwood Heights, Illinois, USA Registered: Jun 2005 posted 08-14-2005 05:46 PM                     Mark, Home THX gear uses a 75dB test tone that is REFERENCED to 85dB. In other words, it is purposely set 10dB lower, so that if you set output to 75dB, it should play back at 85dB. I have a THX controller (pre-amp) but I have never been able to tolerate the so-called "reference level." I routinely run it several dBs lower.  |  IP: Logged Andy Summers Master Film Handler Posts: 397 From: Bournemouth Dorset United kingdom Registered: Jun 2005 posted 08-14-2005 06:36 PM                 Yes this maybe true Robert, too much for taking what sub bass unit are you using, as I’m using the JBL 4645 18in sub THX approved, and this takes a lot of the total madness of past and present motion picture soundtracks, that can be thrown at it. I’ve looked at the main levels of all the other channels, from the centre channel which can have just about the same amount, of the low frequency content as the LFE. What I did was work this backwards, set the THX reference level to 0db and turning the volume up on the amplifiers, to achieve an 85dba weighting in the centre of the room, the same applies to the main and the split-surrounds, with lows reaching 105dbc weighting and adjusting the EQ for each channel looking closely for any problems like popping any distortion values, and the results are within the operational tolerances. With keeping everything separate form the AVR, pre-outputs is what I’m using with EQ and an Active crossover on the centre channel at the present moment the timber balance over the fronts is cinema sounding? For a small room, its fitting and one friend said he was in the film, and him and his girlfriend likes to see “Dragonheart” on Tuesday with making special adjustments to this film to make it a tour-de force event. So now on with “Superman the Movie” now, 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.  |  IP: Logged Mark Lensenmayer Phenomenal Film Handler Posts: 1605 From: Upper Arlington, OH Registered: Sep 1999 posted 08-14-2005 09:30 PM                     Robert, I agree that it is much too loud at reference setting. I typically run 10-13 dB below, and it sounds good to my ears. Sometimes, though, when I demo, I slowly crank it up. The FIREBIRD section of FANTASIA 2000 is good for this, as is the opening of PAINT YOUR WAGON. I certainly don't go to the great pains that Andy does when he watches something! I don't care what the numbers are...I just want it to sound good!  |  IP: Logged Andy Summers Master Film Handler Posts: 397 From: Bournemouth Dorset United kingdom Registered: Jun 2005 posted 08-28-2005 12:34 PM                 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 KABOOM… 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. Ashley  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 08-28-2005 01:00 PM                     I'm still trying to figure out what you think you are accomplishing here. Even at that, you are using home equipment and the home remixed versions of these soundtracks. Using the theatrical mixes would be the proper way to evaluate soundtracks, but even at that, what is the purpose of this???  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 08-28-2005 01:35 PM                        But... Aladdin lets you choose between the home 5.1 mix (gawdawful) and the theatrical 5.1 mix. I think that is what he is trying to accomplish, purchasing Aladdin.  |  IP: Logged Jesse Skeen Phenomenal Film Handler Posts: 1517 From: Sacramento, CA Registered: Aug 2000 posted 08-28-2005 03:36 PM                     Well, neither mix of Aladdin includes the original song lyric "Where they cut off your ear if they don't like your face", so don't know why they bothered.  |  IP: Logged Andy Summers Master Film Handler Posts: 397 From: Bournemouth Dorset United kingdom Registered: Jun 2005 posted 09-13-2005 07:29 PM                 Brad, Hi there and how are we feeling, good ok then I will proceed, the purpose of the LFE test is that most home cinema owners play it way to loud, I mean to the point where you can hear it across the road, and know wonder they do the sub bass in, when not even one year old. So I started to look at this from a different angle and viewing some of the possible Armageddon’s that’s where you start seeing smoke followed by a total failure to the sub bass unit, and though I’ve been running the JBL 4645 now for 7 yeas with no problems and the sub bass driver as a newer driver running this beautiful sub bass. Your screening room Brad, uses five dual sub bass units, though I’m not sure what make or model, your five-screen is JBL 4675-A, you have got taste in choice, so what’s the name of the subs and there power handling frequency response each, and with the total overall frequency response, what is the setting of the sub bass level, with the fader at (7) Dolby reference level on the CP-500 as well as SDDS CDS and dts. Anyway I’ve noted “STAR WARS EPISODE 3 ATTACK OF THE CLONES” having the highest LFE peak level when the spaceship is targeted at the begging KABOOM, and now I’ve reset the fader level that outputs the level along with an EQ in line with a spectrum analyzer, and setting the level for its display to show a peak, well just under the clipping point. And the rest of the film plays superfine with lots of low end from the three-screen and split-surrounds as well, the blending of lows from the three-screen going into the mixer and setting the balance to present good blending of the LFE and three-screen is seamless and powerful, more better than one cinemas in Bournemouth’s Westover Road, where I have noted poor blending of or should I say overpowering of the LFE. For example “STAR WARS EPISODE 1 THE PHANTOM MEANCE” the lightsaber dual with “DARTH MAUL” there was a point where master JEDI knocks or fists “DARTH MAUL” has he hits the bottom flat on his back with a thud, not felt much in the cinema, and master JEDI “Qui-Gon” jumps down only to get kicked in the face again not felt much, nor threatening then come more slamming of the LFE to a point where it sounds like it’s going to give up the ghost any moment now. It was a piss poor set up of professional standards, sorry to say that just being honest as can be, and it get worse I also noted as film as scene in a different cinema only the LFE had a whole lot more low end extension, again the blending of LFE into three-screen was a joke, and again with UCI cinemas where I first started out as a projectionist 16 years ago, seeing the film in one of those no bigger to swing a cat in cinemas, the sound presentation playback was a major taking the piss time joke of all jokes. No wonder cinema admissions have been so low this year, with more home cinema owners getting smart, well there may not have Dolby CP processors but this is wake up call, where one as a good home cinema ones friend will what one too, and so on getting the picture so far, so cinemas have to pull there socks up, with standards of film presentations like “INDIANA JONES AND THE LAST CRUSADE” 70mm with JBL 4675-A JBL 4645 and JBL 8330 via the LUCASFILM LTD THX SOUND SYSTEM 3417, was one road show event I will never forget EMPIRE cinema London September 13th 1989 £6.00 rocker chairs and laser show too top it interior decoration WOW +10x infinite… I didn’t mention the “MATRIX RELOADED” the LFE came under “STAR WARS EPISODE 2” so no readjusting of the fader level is required, I’ll cheek out the other MATRIX flicks later on and the “HULK” and bets on whither this will peak over (0db) on the LFE sending “STAR WARS EPISODE 2” down leaving HULK at #1 spot? Any takers…. Joe, I don’t have “ALADDIN” on DVD yet though I have so others like “BEAUTY AND THE BEAST” “MONSTERS, INC” there the animated ones in the Disney collection. Jesse, I’m wondering just how much a film changes from theatrical sound mix to DVD mix how much of the dynamics have been altered, anyway less is more and turning the LFE up to +10 sounds to much well more like damaged goods to some owners sub bass speakers placing the SPL db meter in the middle of the room I’ve noted the response is not valued, placing it @1 meter form the sub bass and setting the amplifier volume level for the LFE is more spot on, has I can still feel it pressing on me and setting the SPL db meter in the middle of room for the three-screen channels testing to a max SPL 105dbc weighting when its called for within the mix. With the Split-surrounds with EX and “sonic whole overheard” all peaking at SPL 105dbc weighting in the middle of the room. Would you like to bet on “SPIDERMAN 2” though I’m not going to have much time to do another LFE tests while at college studying Access media. Ashley PS Bard, sorry I almost forgot, I would like to test the theatrical 35mm SR-D prints and the SDDS the dts ones to the max, but think about it, it’s going to take a whole lot my time up as well as someone else’s as well, with DVD its hit the chapter that you believe to be the most powerful scene in the film, and your away talk about cutting to the chase….  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 09-13-2005 08:25 PM                     Andy, regardless of what equipment is installed, if the acoustics and tuning are not up to par, the system will sound shitty. Also, your testing of this really proves nothing, as DVDs have different mixes of the audio from the theatrical releases. In fact, even if they weren't, I STILL fail to see any purpose to this thread or your tests. May I recommend you take this to the AVScience forums? I'm tired of receiving mail about how ridiculous this science experiment of yours is. THREAD CLOSED  |  IP: Logged

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