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How to place my speaker for louder sounds?

  1. Mar 8, 2013 #1
    Referring to following image, I would like to know which setting for speakers I would receive louder sounds.

    Those speakers are separated by 0, 90, 120, 180 degrees.

    Does anyone have any suggestions?

    Thanks in advance for any suggestions



    Speakers_zps1fba5ac9.jpg
     
    Last edited: Mar 8, 2013
  2. jcsd
  3. Mar 8, 2013 #2

    sophiecentaur

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    Hi.
    There's no easy answer to this. The position of walls and the room acoustics can also have a massive effect. It also will depend on the range of listening positions you want to feed with your high level sound. If you don't care about stereo, then side by side will be less likely to produce cancellation an any one position in the room. If you have them facing each other or in line (1 and 4) then there will be cancellations (dips) at some frequencies when you are not directly on the mid position. Perhaps 2 and 3 would be best. You'd need to try it out in-situ.
     
  4. Mar 8, 2013 #3
    Is that mean that any cancellations at some frequencies will only occur in line (1 and 4), not in line (2 and 3)?

    Do you have any suggestions on how to locate the spot for harmonic vibrations (louder sounds)?
    Which setting will be better to locate this spot?

    Thanks you very much for any suggestions
     
  5. Mar 8, 2013 #4

    sophiecentaur

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    The geometry of that arrangement means that the path difference from the two speakers is more likely to be a half wavelength out, particularly when they're facing each other. When they're co-sited there would never be a path difference - side by side, less likely and only at a large distance away.
    I haven't come across the term Harmonic vibrations in this context but nearer will be louder (obviously) and equal distance will be loudest (all frequencies will produce addition). If you can hit a resonance of the room, of course, that will increase the loudness at some frequencies.

    PS Are you determined to knacker your hearing, young man?
     
  6. Mar 8, 2013 #5
    Acoustics can be kinda magic.
    There are so many parameters to take into account, you won't get a one in one formula for these.
    What material is the walls made of in your room? the ceiling the floor? how full the room is with furniture how much space there is etc etc .

    personally i would go for figure 3.a nice 120 grade apart speaker stereo system with some good records and quality speakers/amps/playback devices can sound really good.


    Quite honestly I think if you are done with your cables and apparatus then just experiment with the loudspeaker arrangement.Put them in one place listen then in another and listen again.
    This is really about taking a day off and doing some experimentation that is pretty much the best way you will see what positions suit you best.
     
  7. Mar 8, 2013 #6
    Do you mean that 1 and 4 arrangements are more likely to be in phrase (resonance) or out of phrase (half wavelength out)? when I move my position across the room.

    If I want to minmized any resonance of the room, so people can listen the same level of loudness any place within this room without feeling any big different between spots, will line (2 and 3) be a better choose than line (1 and 4)?

    Thanks you very much for any suggestions
     
  8. Mar 8, 2013 #7

    For figure 3, will 120 degree be better than 90 degree to minmize any resonance of the room? so people can listen the same level of loudness any place within this room without feeling any big different between spots.

    Thanks everyone very much for any suggestions
     
  9. Mar 8, 2013 #8
    put up curtains, soft furniture...rugs.....any sound absorbing materials....

    experiment....
     
  10. Mar 8, 2013 #9
    Sound absorbing materials have been considered on walls, floor and ceiling.

    The main issue is to select the best arrangement for speakers' location.

    Do you have any suggestions referring to above discussion?

    Thanks everyone very much for any suggestions

    noise_damping_acousti_deluxe.jpg
     
  11. Mar 8, 2013 #10

    sophiecentaur

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    If you are really serious about making a 'listening room' you will also need LF absorbing panels. Those 'egg box' / foam absorbers will not take care of the low frequency resonances. You are talking large shallow boxes, hung on the walls, with diaphragms of perforated hardboard and filled with fibre. I have seen designs in various places. However, many people like the non-high fidelity effect of boomy sound colouration - hence the popularity of sub-woofers.
    Some advice. When this is all finished and you sit back to listen, do not dare to risk doing a frequency sweep of your room with a tone source and microphone. It will almost certainly look like a dog's dinner and totally spoil your enjoyment of what will be a really 'nice' sound. Flat frequency response???? Oh yeah. But a real room is a real room and when do we hear any live music in ideal conditions?
     
  12. Mar 8, 2013 #11
    I'd read this [which I did not] and the associated links [which I did not] and
    see if you get any ideas....

    http://en.wikipedia.org/wiki/Sound_design#Theatre

    You can also check installation suggestions from your speaker manufacturer....
    SONY had some clear recommendations for surround sound speaker placement which
    I used when I upgraded my TV.

    I always sit in the same spot [linda like Sheldon Cooper#] so I don't much care
    if other spots are uneven!!

    # He's the rather nutty physics PHD on 'BIG BANG THEORY' on tv!!
     
  13. Mar 11, 2013 #12
    The wave equations that work for light also work for sound, BUT C becomes the
    speed of sound in the medium.
    We can assume about 1000 feet per second,
    so the wavelength of sound at Frequency X =
    1000fps/100 hz = 10 feet
    1000 hz = 1 foot
    10,000 hz = 1.2 inches
    20,000 hz = .6 inches
    For any giving frequency you could calculate the point of constructive interference,
    but it would only be good for that frequency.
    (and "point" is a subjective term with a 10' wavelength.)
    Based on your drawings, I would say figure 3, and adjust for desired effect.
     
  14. Mar 11, 2013 #13

    sophiecentaur

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    The reflections from the walls and ceiling will tend to fill in any potentially serious nulls caused by your speaker positioning and you are unlikely to be listening to 'swept tone' (unless you are into avant garde stuff). The sound colouration of the room is likely to be at least as strong as anything due to the speakers. Just sit back and enjoy. If you want good stereo then sitting at the apex of an equilateral triangle is probably as good as you're likely to get in a real room. You need to have a good central image without too much 'ping pong' stereo effect.
    But you OP talks of "louder sounds" ???
     
  15. Mar 12, 2013 #14
    Let's hope the poster knows enough by now to realize that is
    not a good, nor a useful, objective.
     
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