Dolby says...

Discussion in 'Archived Threads 2001-2004' started by armin, Aug 27, 2002.

  1. armin

    armin Extra

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    Dolby says to have the fronts the same height as the centre channel. Has anyone tested this out vs. having the centre channel on top of their tv and the fronts lower ?

    Dolby says to have the surrounds 2-3 feet above listening area. Has anyone tested this theory out vs at ear level ?.

    I have 2 rears as well. I guess they go at the same height as my side surrounds (2-3 feet above listening area)

    armin
     
  2. Neil Joseph

    Neil Joseph Lead Actor

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    A direct radiating speaker's sonic characteristics will change as you move off axis vertically and horizontally. Ideally, you would want the speaker facing toward you and you would want to be in the plane of the speaker, especially the tweeter. By having any speaker much higher than the other, the timbre of that speaker will differ from the other, even if they are the exact same model.

    Now in the real world, it is not always possible to have all of the speakers at the same level wrt the listening position. What happens if you have a large RPTV with the centre speaker mounted on top, does that mean you have to go out and get 52" stands???

    What you must try to achieve then is aiming the aiming the tweeters at "ear level" while seated in the main listening position to accomodate for variences in setups as mentioned previously.
     
  3. Holadem

    Holadem Lead Actor

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    Dolby also said to play at absolutely ridiculous levels (reference anyone?)

    Dolby also (probably) said to have identical speakers all around.

    The key is to not give a flying sh!te about what Dolby says.

    Just kidding, the key to to get a s close as possible to what Dolby says without compromizing my enjoyement.

    If I was to do exactly what Dolby said, I would have a third tower standing right in front of my TV.

    --
    Holadem
     
  4. Neil Joseph

    Neil Joseph Lead Actor

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    Now that's funny.

    I can't say I disagree with anything Holadem has just said.
     
  5. JesseR

    JesseR Stunt Coordinator

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    depends on the speaker too..im pretty sure jbl says for the s-38s they need to be on stands 18-24 inches tall and the s-center is fine up on a tv..somethign about their tweeter..but it seems to work fine for me like that
     
  6. greg_t

    greg_t Screenwriter

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    I agree with Neil. I don't think we need to follow Dolbys recommendation to the letter to enjoy home theater, but they have developed standards based on years of testing and experience.
     
  7. jeff lam

    jeff lam Screenwriter

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    The best you can do is angle the center down toward the listening position. The main L+R speakers should be at or just below ear level.
     
  8. Ned

    Ned Supporting Actor

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    Dolby never said you had to listen at reference at home.
    Having the front 3 speakers on the same horizontal plane is basically not possible with a regular or rear projection tv. There is just no way to do it that gives you an acceptable layout of the speakers and display.
    It would be better to think of these as recommendations for the ideal home theater. Try to get your system as close as possible to the recommendations for best results [​IMG]
     
  9. MartinV

    MartinV Stunt Coordinator

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    you can have all fronts the same height if you invest in Front Projection rather than Rear.

    When I get the new Sony HS-10 (Cineza) FP this winter, I'm going to have my center on a stand or cabinet to match the height of my towers.

    But most people have direct view or RPTV, so obviously that's not going to work.
     
  10. Jeff_M

    Jeff_M Stunt Coordinator

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    When I moved into the world of front projection earlier this year, I did so to get that "big" movie theater feel. I never imagined this would help my theater's sound as well! Now I have 5 identical full range towers (matching tower as a center channel where the TV used to be!) While Dolby's recommendations may not be realistic for everyone, they give you some thing to work towards.
     
  11. Philip Hamm

    Philip Hamm Lead Actor

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    I nominate Holadem for post of the week.
    It sure is nice to have met some of the faces behind the posts at meets. [​IMG]
     
  12. Henry_W

    Henry_W Stunt Coordinator

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    Armin -

    My answer to your first question regarding front speaker placement. The set up is RPTV with Klipsch Heresy II mains and center trials were both an extra heresy and Acoustic Research AR2C as center. The obvious stuff on placement was the same regardless of center speaker used, so here goes:

    1. Center on floor below RPTV and mains bottom even with top of RPTV - results all over the place. Angle bottom toward listener and center was over bearing and inconsistent. Straight out and the center almost seemed to fade in and out. Very disorienting arangement.

    2. Center on top with mains on floor. Imaging (right term?) was really wierd. The center was much more consistent but the mains got flaky. Left to right (and vice versa) was tremendously disorienting at times, so the problem seemed to move to the mains.

    3. Center and mains on floor. Much, much better. The main problem I noticed here was that (since in my arangement the RPTV is elevated 20 inches off the floor) the sound obviously came from below.

    4. Center and mains above RPTV and within 4 inches. Excellent results with clarity (as always based on the quality of the sound source) not achieved with other placements. Dialog is clearer and imaging is wonderful. Once set up it is only adjusted at the reciever for a few 'different' quality mixes. Further, since I am using this for 2 and 4 channel music - the elevated mains give me a better music fill.

    My results - yes, clearly keeping the speakers on the same plane was an obvious advantage in my arrangement.
     
  13. Pablo Abularach

    Pablo Abularach Supporting Actor

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    I dont disagree with Dolby statement about speakers placent, because they now much more than I do. But for me everything depends on the acoustic of the room, you phisical limitations (placement of speakers), WAF, etc.

    For me putting my Bookselfs at 7 feet, gave me (I think) a filling sensation, although you more or less can stablish the speakers are on the top, I think is better than lower. And I have my center channel at 5 feet, works great, I think having it right above the TV gives you a more center sound over the TV (dialogs). If I put it at the same height of the bookselfs I think I loose some accuracy of dialogs because sound wont be in the same level as the picture.

    I think everything is relative, there is not a sure way to place them, what I would do is try Dolbys suggestion, and yours, and see what works best for you.

    Hope this helps,
    Pablo Abularach
     
  14. Arron H

    Arron H Second Unit

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    One of these days, I should probably try my B&W 603s on stands to put the tweeters across the front at the same height. I would be very concerned about the stability of the 603s on stands, especially because of my hypertensive cat who tends to use the 603s as a gymnasium already [​IMG] Does anyone know of any really stable stands that might work with a tower speaker?
     
  15. Mark R O

    Mark R O Stunt Coordinator

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    Dolby Labs is exists in a dimension not governed by the same physical laws as our own. It seems they also have invisible, massless seating that adjust according to sonics, hollow decks for family rooms, equipment forged by Dwarf craftsmen, no need for cables and alchemist visions we just can't share. They mean well, but it seems much is lost in translation. If you concern yourself with only the most basic of their text to use as a guideline however, it's pretty useful. But it's hazardous to adopt Dolby Dogma literally. Despite the efforts of some renegade zealots, the main format is still just 5.1 channels, so it's pretty easy for us to get our rigs set up well. Go with the advice the others here have given; experiment and stay practical. And always beware anyone with the letters "THX" displayed on their clothing.
    Ending with a serious suggestion, if you put your center channel on top of the TV, be sure use feet or a stand of some type. Isolate it well, and have the the front of the speaker over-hang the screen as much as possible.
    Good luck!
     
  16. Russ Dunn

    Russ Dunn Extra

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    Ending with a serious suggestion, if you put your center channel on top of the TV, be sure use feet or a stand of some type. Isolate it well,"

    If it's shielded What's wrong w/ just setting it on top of the TV?

    Thanks,
    Russ
     
  17. aldamon

    aldamon Second Unit

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    On the rears:
    I gathered from looking at Dolby's preferred positioning picture that the surrounds are supposed be slightly behind the seating position. Here is what I'm talking about:
    Dolby Surround Placement
    Now, the HT Primer says to point the speakers right at you. When I did that it, the surround speakers were centered in respect to the armrest. The effect of this positioning was awful. Any time I leaned back comfortably in the couch, the "surround" speakers were effectively in front of me. Now that the speakers are back two feet or so, lined up with the back leg of the couch, the surround sound is coming from the the back, even when I lay back. Much better.
    Back on topic, it would look really odd to have the L and R fronts at the same height as the center channel. I also bought four matching stands (CD towers) for all surrounds, so I have ignored the height suggestions entirely.
    What I wonder about is why the surrounds are supposed to be up high when the L-C-R speakers are supposed to be level. My stands are at an identical height all around. I'd think it would be best to have matching speakers at the same height all around.
     
  18. Ned

    Ned Supporting Actor

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    The surrounds are supposed to be high so that you get good coverage and a diffuse rear soundfield. All 5 speakers on the same plane might jive with music but this is movies, and we're trying to simulate a movie theater.
     
  19. Mark R O

    Mark R O Stunt Coordinator

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    Russ,
    It's not a question of magnetic but of mechanical isolation.
    You would not set your main speakers atop a large plastic box for obvious reasons. We often have no choice for the center channel however. Any efforts made to keep the sound from that speaker from feeding into the TV's box will yeild benefits such as cleaner, more precise mids, better dynamics and volume and tighter image focus. It is amazing all the grunts, buzzes, vibrations, hums, echos, etc. a TV cabinet can make. Center channel isolation helps to reduce them. In addition, few speakers sound better sitting flat on the floor than on spikes or disc's or stands, whatever.
    Centers are no exception.
    Those of you who have bookshelf speakers sitting on a shelf, and those with center channels flat on the set top, try this simple test. Place 4 Tic-Tac mints under the speaker near each corner. Replay the tune you just heard before the Tic-Tac mod. Now if a breath mint can change things that much, specialized products may be worth a look.
    Russ, I would be curious to know what you find.
     

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