Really Low Frequency Movies

Discussion in 'Speakers & Subwoofers' started by Ken Burkstrum, Feb 22, 2004.

  1. Ken Burkstrum

    Ken Burkstrum Stunt Coordinator

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    can you guys name some parts in movies where they go reallly far down there, like below 20Hz or around there. I was wondering if in the first matrix when trinity does the slow motion angel kick at the beginning, does that go below 20 when the slow mo is just about ending?

    Im wondering because before i got my sub, my fronts couldnt even deliver the whole thing, it drops and drops and then the last 2 seconds nothing came out of my mains.
     
  2. Dustin Harrison

    Dustin Harrison Stunt Coordinator

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  3. ChrisWiggles

    ChrisWiggles Producer

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    This comes up all the time, run some searches, there are some threads with good lists out there.

    In the interim this is also a good list with visuals.

    http://www.svsubwoofers.com/faq.htm#moviedemos

    Also, there was a thread with similar spectrum graphs, you should be able to find it.
     
  4. Edward J M

    Edward J M Cinematographer

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    Actually, there aren't many that contain really hot stuff well below 20 Hz.

    There are a lot of scenes with big hits in the 22-27 Hz region that have residual components below 20 Hz, though.

    http://bass.jawmail.org/index.php?p=matrix_reloaded

    Note the Hammer Ship rescue scene - primarily centered at 26-27 Hz, with some 17-18 Hz residuals. But also note that red peak at 8 Hz - pretty odd. This scene is very impressive on the PB2+ when tuned to 20 Hz to capture that subsonic stuff.

    Ed
     
  5. Jeremy Stockwell

    Jeremy Stockwell Supporting Actor

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    Ken,

    These threads are the ones with the spectrum graphs to which Chris referred.

    Ming's thread has the graph of Black Hawk Down (post#4) that proves that BHD probably contains the loudest, lowest LFE to date, though not all will experience it (Tony was the first to notice it around here in his thread, "Holy Crap! Sounds to make the sub go baaaaarf."

    [​IMG]

    JKS
     
  6. Edward J M

    Edward J M Cinematographer

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    Agreed - that huge purple/pink/red burst at 5 Hz is definitely the lowest and loudest I've seen.

    It's almost too low, though. Most powered subs have a high pass filter to knock out frequencies below the tune point, and a 5 Hz signal would typically never make it through.

    The PB2+ does have a "Bypass" setting which will allow this signal to pass. In the 16 Hz tune with both ports plugged and the Bypass setting engaged, I can indeed see/feel the woofers responding to this extremely hot 5 Hz signal. It's weird to see the woofers moving so slowly that you can actually count the cycles/second.

    But I have to play this passage at moderate volumes because it would be easy to bottom the woofs in Bypass mode with a 5 Hz signal this strong.

    Daredevil (dts) is more representative of what a great subwoofer should be able to capture in the subsonic region. There are a bunch of short-duration, high-amplitude hits in the 14-16 Hz region in the barfight scene. So low most people don't know it even exists on the DVD - good stuff.
     
  7. Jeremy Stockwell

    Jeremy Stockwell Supporting Actor

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    Ed,

    Agreed, this scene in BHD is not a fair test of what a subwoofer should be capable of. But that's what I love about these waterfall charts, they show everything that is there regardless of what you can hear.

    This extremely strong 5Hz signal in BHD is nearly pointless due to subsonic filtering somewhere in the chain of most peoples' systems, but it's still cool to see that it is there.

    Ming's and Rudi's other waterfall charts show many other examples of what content is available below 20Hz (including Daredevil).

    JKS
     
  8. Allen Marshall

    Allen Marshall Supporting Actor

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    can someone explain to me how that tuning system works on a PB2+ with putting the caps on the airholes and the site says 16hz, 20hz and 25hz. I dont understand what caps you'd put in what to get those certain frequencies by wouldnt you just want to go with 16hz?

    and can the PB2+ do that 5 hz thing in Black Hawk Down Jeremy was talking about? And Edward when you say most people do you mean none SVS owners or people with like humango chango double 18" 10,000 watt amp subwoofers that i'll never own in this lifetime?
     
  9. ChrisWiggles

    ChrisWiggles Producer

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    You lose overall output by plugging the ports for a deeper tune, but gain extension. This is flexibility so you can use things the way you want by tuning things as needed or to taste.
     
  10. Edward J M

    Edward J M Cinematographer

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    Allen, the PB2+ can only play the 5 Hz BHD passage if I disable the high pass (subsonic) filter. This is inadvisable, and I only did it as a test at a moderate volume.

    Most SVS powered subs do not have the capability to disable the high pass filter, and that is probably a good thing since it is designed to protect the woofers from over-excursion below the selected tune point.

    The 5 Hz note in BHD is more of a novelty than anything else, and you won't miss out on the movie experience if your sub doesn't play it. The PB2+ won't play it either if set up in the normal 25 Hz or 20 Hz tune.

    Ed
     
  11. ChrisWiggles

    ChrisWiggles Producer

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    Actually, AFAIK, most SVS subs to not have a high-pass filter. Those that do you can disengage it if you want. I'm pretty certain that mine (pci 20-39) does not have a high-pass filter.
     
  12. Allen Marshall

    Allen Marshall Supporting Actor

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    even the B4+ wont play that part? what kind of subs do? How much does a "Tempest" cost?

    Jeremy i was lookin at those spectrum graphs, call me an idiot but i have no idea what to make of that
     
  13. Lewis Besze

    Lewis Besze Producer

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    Well my subs can play BHD no problem even at close to refference.One of my sub is a PR design and I can almost count the cycles as they slowly move in and out during the "Fuckin' Irene" scene.I dodn't have any infrasocic filtering in my system.The PR's are tuned to about 18hz and usually gives me good indications if the soundtrack has strong output below 25hz.Terminator 3, Underworld, and Saving Private Ryan, among the ones that many people thinks is bass "nirvana" but they don't have much below 30hz,as my PR's barelly or don't move at all.
    Regarding Matrix Reloded,the landing of Morpheus's ship at the beginning to "Broadcast Level" has some scary output at very low FR foundation as it's barelly audible but one sure feels it with a good sub. MY PR's went nuts on this one! [​IMG]
     
  14. Edward J M

    Edward J M Cinematographer

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    ChrisWiggles:

    All SVS powered subwoofers employ a high pass filter to protect the woofer from over excursion below the tune point.

    The high pass filter is often referred to as a "subsonic" filter (I've done it myself many times), but since some of them kick in at about 22 Hz on the 25 Hz tuned models, that term really isn't as technically accurate as simply calling it a high pass filter.

    The slope of the high pass filter, and the amount of any EQ applied to flatten and extend the response is specific to each model and tune point.

    Regardless, the high pass filter on the PCi and PB1-ISD models is not user adjustable. It is user adjustable on the PC+, PB1+, PB2+, and PB2-Ultra models - this would be your "tune switch", to be used in conjunction with the port plugs. It can also be completely disabled on the PB2+ and PB2-Ultra models.

    The only way to play that 5 Hz passage on the PB2+ is to plug two ports and set the high pass filter to disable. You certainly can't hear it, but you can feel it at moderate levels if you are close to the sub. I wouldn't recommend playing it at a loud level because it would probably bottom the woofers. Again, I consider that passage to be more of a novelty than anything else.

    And yes Allen, the B4+ will play that passage (probably pretty loudly) if you plug 3 ports and make sure you don't have a high pass/subsonic filter anywhere in the loop (like the SVS01 Marchand Bass Box).
    Regards,

    Ed
     
  15. ChrisWiggles

    ChrisWiggles Producer

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    "All SVS powered subwoofers employ a high pass filter to protect the woofer from over excursion below the tune point"

    It was my understanding that this is not the case, as also evidenced by excursion graphs I've seen for SVS. I certainly could be wrong, as I would actually welcome a subsonic filter on my SVS, and that would be welcome news to me. I will shoot a quick email to see what SVS has to say, and report back.
     
  16. Edward J M

    Edward J M Cinematographer

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    That quote was pretty much straight from the horses mouth (not that I consider Tom V to be a horse). Check if you want, but I think you'll find the 20-39PCi BASH amp has a built-in high pass/subsonic filter (at least 2nd order, maybe steeper), probably kicking in around 17 Hz. [​IMG]

    The tune point graphs SVS supplies are probably more reflective of the passive models, which would indeed show a rising excursion below the tune point. I haven't seen a graph for a powered model that actually reflects the effect of the high pass filter on woofer excursion below the tune point.

    Ed
     
  17. ChrisWiggles

    ChrisWiggles Producer

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    Indeed you're right, which is certainly positive news to me!

    I quote Ron's response to my email:

    "One of the reasons our PCi subs work so well is in fact that each
    enclosure size has its amp custom tuned to that sub. This includes a
    carefully calibrated set of subsonic filters and nominal levels of fine
    tuned equalization that's not accessible to the customer as you noted.

    So you do indeed have a subsonic filter that's adjusted just for your
    sub and it's one of the reasons we can offer just the right sub, with
    just the right performance. The 20-39PCi is still one of our most
    popular subs for this reason I'm sure.
    "

    [​IMG]
     
  18. Zack_R

    Zack_R Stunt Coordinator

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    And this is why you rarely if ever here of anyone bottoming a PCi sub.[​IMG]
     
  19. Mitch Stevens

    Mitch Stevens Supporting Actor

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    This question has been asked before, but it has not been answered. WHICH VERSION OF BLACK HAWK DOWN is this? Do both versions have the same 5hz sound during that scene?
     
  20. Jeremy Stockwell

    Jeremy Stockwell Supporting Actor

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    Mitch,

    Yes, both versions of Black Hawk Down have this signal. I borrowed the original 1-disc version from my local library and I own the 3-disc Deluxe Edition. It's on both.

    JKS
     

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