What makes a 15Hz tone "better" than a 30Hz tone?

Discussion in 'Archived Threads 2001-2004' started by Bob_A, Nov 12, 2001.

  1. Bob_A

    Bob_A Supporting Actor

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    And why would sound engineers feel the need to place a 15Hz tone instead of a 30Hz tone?
     
  2. Tor Arne

    Tor Arne Stunt Coordinator

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  3. Bob_A

    Bob_A Supporting Actor

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    You can't feel a 30Hz tone?
    But don't they even have material below 10Hz on soundtracks these days? Would we even want to reproduce this? Is this good for our health? [​IMG]
    [Edited last by Bob_A on November 12, 2001 at 11:41 AM]
    [Edited last by Bob_A on November 12, 2001 at 11:43 AM]
     
  4. Saurav

    Saurav Cinematographer

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  5. Tor Arne

    Tor Arne Stunt Coordinator

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  6. Bob_A

    Bob_A Supporting Actor

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    Just makes you wonder...
     
  7. Jack Gilvey

    Jack Gilvey Producer

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  8. Bob_A

    Bob_A Supporting Actor

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    Jack, I am not sure what you meant by those one word questions, but anyway...are you saying that it is preferable to record certain soundtrack elements at 5, 10, 15Hz instead of 25, 30 Hz? Fine...but what about your health? [​IMG]
    [Edited last by Bob_A on November 12, 2001 at 12:51 PM]
     
  9. Jack Gilvey

    Jack Gilvey Producer

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    quote: Jack, I am not sure what you meant by those one word questions, but anyway...[/quote]
    I'm unsure what you mean by "better" as applied to certain frequencies. I'm unsure if , by the term "instead", if you're implying that those frequencies are interchangeable.
    quote: are you saying that it is preferable to record certain soundtrack elements at 5, 10, 15Hz instead of 25, 30 Hz? [/quote]
    I said nothing about what it's "preferable to record". I do, however, think that it's preferable to have the capacity to reproduce what is recorded. You seem to be saying that a fundamental can be substituted for with its harmonics.
    I imagine that soundtrack engineers have an effect they are looking to achieve with certain frequencies. Is there another reason you see, perhaps something more conspiratorial? [​IMG]
    What about my health? Are you stating that deep bass is bad for health reasons? I have no medical opinions on that.
    [Edited last by Jack Gilvey on November 12, 2001 at 01:07 PM]
     
  10. Bhagi Katbamna

    Bhagi Katbamna Supporting Actor

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    I do think that part of the reason this is done is to replicate the experience. I was in Las Vegas when they imploded the Desert Inn and even 1/2 mile away in my hotel room, I could feel the ground rumbling. Another reason is to bring out more people to the theater. Not everyone has hometheaters and powerful subwoofers, in fact most people watch movies on the VCR and TV so having a super soundtrack will attract those people to the theater.
     
  11. Bob_A

    Bob_A Supporting Actor

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  12. Brian Bunge

    Brian Bunge Producer

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    Bob,
    I do know that sub 10Hz frequencies can be hazardous to your health. The question is, at what level is this the case? I don't imagine the amplitude of the sub 10Hz signals would be high enough to be of such concerns. I think infrasonic signals will be great for the proposed discrete tactile channel that Chris_A keeps talking about.
    Jack's reasoning that you seem to be referring to harmonics is that 30Hz is a 1st order harmonic of a 15Hz signal (I think that's right) and by using the two in your example it sort of implies that's what you meant. If not, that's fine.
    Brian
     
  13. Jack Gilvey

    Jack Gilvey Producer

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    quote: "Better" meaning why would a sound engineer find it more desireable to use a 15Hz tone opposed to, say, a 30Hz tone. It is a pretty straightforward question IMHO...but there you go.[/quote]
    Experiencing both properly might illustrate the reason but...there you go.
    quote: Read my reply above. Obviously two different frequencies are not interchangeable...but the whole idea of this thread is to try to understand why an engineer would consider using an "ultra" low frequency as opposed to, say, 25 or 30 Hz. [/quote]
    See reply above. There's usually not an infrasonic sounnd without a higher counterpart, though. Usually.
    quote: Why do you say this? I am asking people why a sound engineer might consider using ultra low frequencies in the soundtracks...even frequencies below 15Hz which almost no system can reproduce "adequately". I am not sure why you are getting so defensive.[/quote]
    No defensiveness here, don't know where that came from, trying to see what you're asking. Again, I can only imagine those frequencies are there to achieve an effect. I think that , most of the time, they are "doubled" up higher so that some of the effect can be heard by all. This is done with very low organ stops also.
    quote: Fine...but soundtracks with sub-10Hz information? Any ideas what this would accomplish?[/quote]
    Not specifically, you'd have to ask an engineer. However, not too long ago, before such capable subwoofers were so common, you could have substituted "30Hz" in your question above.
    quote: That idea was discussed in a current thread, and it certainly is a valid concern IMHO...but generally I said that as a joke. Lighten up.[/quote]
    Hehe, nobody's lighter than I. Thanks, anyway.
    I would assume that any frequencies put into an artificial movie soundtrack are there for a reason, and maybe that reason is "for fun". I know that's all I need.
    quote: Jack's reasoning that you seem to be referring to harmonics is that 30Hz is a 1st order harmonic of a 15Hz signal (I think that's right) and by using the two in your example it sort of implies that's what you meant. If not, that's fine.[/quote]
    That's what the numbers suggested, and that's why I asked.
    [Edited last by Jack Gilvey on November 12, 2001 at 02:33 PM]
     
  14. Bob_A

    Bob_A Supporting Actor

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    Good point Brian. When I said "it makes you wonder", I meant "it makes you wonder why/how sound engineers decide on using a certain frequency (frequencies) to convey a particular effect".
    So it seems to me that the tactile quality of sub 20Hz bass is of a nature which cannot be captured at, say, 25-30Hz...correct?
    [Edited last by Bob_A on November 12, 2001 at 02:35 PM]
     
  15. Bob_A

    Bob_A Supporting Actor

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    quote: I think that , most of the time, they are "doubled" up higher so that some of the effect can be heard by all. [/quote]
    So...if your sub can reproduce both, say, 15Hz and 30Hz at the same levels, what will happen? You hear the 15Hz effect and 30Hz effect at the same time?
    quote: However, not too long ago, before such capable subwoofers were so common, you could have substituted "30Hz" in your question above.[/quote]
    Sub-30Hz effects are one thing...but sub-10Hz??? Even if someone did have a sub which could play flat to this level, I can't see any reason why someone would want to "accurately" reproduce such low frequencies...unless they wanted their intestines to shake [​IMG]
    quote: No defensiveness here, don't know where that came from, trying to see what you're asking. [/quote]
    Your tone just came across as somewhat "cold"...and now I see you trying to throw my own words back at me. You don't like me very much, do you? [​IMG]
    [Edited last by Bob_A on November 12, 2001 at 02:55 PM]
     
  16. Jack Gilvey

    Jack Gilvey Producer

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    quote: So...if your sub can reproduce both, say, 15Hz and 30Hz at the same levels, what will happen? You hear the 15Hz effect and 30Hz effect at the same time?[/quote]
    Sure.
    quote: Sub-30Hz effects are one thing...but sub-10Hz??? Even if someone did have a sub which could play flat to this level, I can't see any reason why someone would want to "accurately" reproduce such low frequencies...unless they wanted their intestines to shake [/quote]
    Sounds like fun.
    quote: Your tone just came across as somewhat "cold"...and now I see you trying to throw my own words back at me. [/quote]
    The ones about not being defensive, or about lightening up? [​IMG]
     
  17. Bob_A

    Bob_A Supporting Actor

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    quote: The ones about not being defensive, or about lightening up? [/quote]
    Neither...I was thinking of something else [​IMG]
    quote: That's just silly. What does a stupid home theater topic have to do with liking someone? You're ok in my book.[/quote]
    Your reply just came across as mocking to me...
    Of course I was kidding when I said that you don't like me...but there must be something about my style which you take issue with heh. But maybe not. I can tell you one thing...I am pretty sure that there are some people who are ticked at me after the "debate" with tom (probably not you though) [​IMG]
    Take it easy.
    [Edited last by Bob_A on November 12, 2001 at 03:09 PM]
    [Edited last by Bob_A on November 12, 2001 at 03:11 PM]
     
  18. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    30hz is the 2nd harmonic of 15hz(the first is considered the fundamental).
    to ask why an artist would include 15hz material is to ask why the artists involved(sound engineer,mixer,director,writer,ect)...include anything you hear or see in the film. In a more general sense...they might be trying to add a sense of foreboding to the scene...or they might be trying to realistically recreate a given effect in the scene. Real life doesn't filter out
     
  19. Jack Gilvey

    Jack Gilvey Producer

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