bi-di-pole suround speaker? help1

Discussion in 'Speakers & Subwoofers' started by Greg Labate, Sep 9, 2004.

  1. Greg Labate

    Greg Labate Stunt Coordinator

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    I just purchased the Swan R3 bi-di-pole surround speaker for my home theater. How does a bi-di-pole differ from a dipole or bipole speaker? Now I'm worried if I bought the wrong speakers, because they will have to be placed on the wall directly above my couch, which is against the wall. Should I cancel my order and buy different surrounds? Or can I just aim the speakers downward to fix the problem? Help!
     
  2. Brian L

    Brian L Cinematographer

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    A basic dipole has two sets of drivers on opposite sides of the cabinet firing out of phase. You normally want to set them to your sides, such that your ears are more or less aligned with the center of the cabinet. The intent is that the out of phase drivers will create a diffuse effect in the null created by the two drivers.

    A bipole has both drivers firing in phase, which should produce a less diffuse effect.

    I do not use either, nor am I familiar with the speakers in question (if they are called di-bi-poles, I am guessing they can be switched from one configuration to the other?), so I will defer to others as to what would work best given your intended location. I would guess bipoles would be a better choice since you can not achieve optimum placement for dipoles.

    You want to search a bit, as there has been quite a lot of recent discussion about dipoles an drear speaker placement in general.

    BGL
     
  3. Greg Labate

    Greg Labate Stunt Coordinator

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    Since it now seems that it would be a waste to get dipole speakers with my room configuration, here are a few follow up questions:

    1. The Swan R3s can be switched to bi-pole. Would that solve the problem?

    2. The Axiom system I first looked at has surrounds that are "quad-polar" speakers. Here is the description: "With twin titanium tweeters and dual aluminum woofers top and bottom, the QS8 delivers all the dynamics present in Dolby Digital and DTS soundtracks. The Quadpolar QS8s are best in medium to large rooms with moderate to high-powered amplifiers or receivers. .. We recommend the specially designed QSS Speaker Stand that allows the bottom woofer to fire freely. Alternatively, the QS8 can be wall-mounted using the bracket it comes with, or our new Full Metal Bracket. Please note the speaker cannot sit on a bookshelf - it has to be elevated." So would buying this solve my problem?

    3. If I'm not going to buy the Swan surrounds, should I just cancel my Swan order and go with the Axioms or Rocket ELTs (which do not have a special suround speaker and instead just uses another bookshelf speaker)

    Help! I would need to cancel my Swan order soon!
     
  4. Rob Kramer

    Rob Kramer Second Unit

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    I would buy another pair of 2.1s and place them on stands in the back corners (facing the listening position) a slightly higher level than the fronts (to clear the bodies on the couch).

    I would also try to keep the couch at least 12" away from the back wall. And if you could squeeze a sub back there - great!

    I think bi/di poles are over-rated. Maybe they are good if you have a really long (or wide) room, or if you have multiple rows of seating (as in a theater), but for the most part ... just over-rated.

    Oh, and I also think that a 3.1 system is UNDER-rated (unless you are into multi-channel music). So if you have a really tight space, dont be afraid to put the extra money (by not buying rear speakers) into better fronts - such as the 5.2s. You could always add rears later.
     
  5. Brian L

    Brian L Cinematographer

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    Sub behind the couch Rob? Geesh, you been peeking in my windows?[​IMG]

    Thats what I have settled on (the rumble in the couch is astounding!), and I do have the rears to the sides and slightly behind the couch...works brilliantly for MC music, and does a damn fine job (IMHO) with films too.

    And Greg, please don't draw conclusions based solely on the opinions expressed here. While it is optimum for a dipole to be positioned so that your rears are in the null, its will produce sound no matter where you place it.

    In spite of what some may say, there are very, very few absolutes in HT. You may find that they provide a great sense of envelopment on the back wall. Given the way you describe your room, you might even mount them so that the drivers are aiming up/down, not left/right. That would give you some direct sound from the bottom driver (which you might like for music and also discrete sound effects) and reflected sound from the top driver, which would be great for ambience.

    In thinking about that, I should think a dipole or bipole would work equally well.

    Most of us have room issues to deal with, and few are able to position things in a text-book perfect manner. In spite of all that, lots of us are getting great sound in less then perfect rooms.

    BGL
     
  6. Kevin C Brown

    Kevin C Brown Producer

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    I can add some of my own experience. [​IMG]

    A lot of people (but not all) prefer dipoles for movie soundtracks.

    A lot of people prefer direct radiators (monopoles) for multichannel music.

    I had direct radiators, and agree that for MC music they worked very well, but they definitely did not work in my room for movies. Way too localizeable. Kept drawing my attention away from the movie to the speakers in the back of the room.

    So I ended up with bipoles (omnipoles really, from Mirage, but same idea). IMO, if you are stuck with 1 type of speaker, a bipolar speaker is the best compromise in the back of the room for the pinpoint imaging you want for MC music, but yet they have added diffuseness over direct radiators which make them also work well for movie soundtracks.

    But, everyone is different, rooms are different, eqp setups are different, so you should try what you can, and decide for yourself what you prefer. [​IMG]
     
  7. EricSm

    EricSm Stunt Coordinator

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    Greg,

    It seems your speakers are bipole/dipole switchable. This is exactly what you want. If you are putting them behind you switch to "bipole" if on the sides try "dipole."
     

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