Back surrounds for 7.1

Discussion in 'Speakers & Subwoofers' started by John Menoni, Aug 17, 2005.

  1. John Menoni

    John Menoni Stunt Coordinator

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    I am going with a 7.1 setup for my very long and narrow room. It is 27 ft long but only 79 inches wide in one area of the room. I only have 61/2 ft ceilings. My 5.1 system is an M&K 150 THX system. I didn't know if I should go with a direct radiating speaker for the back surrounds or if I should go with a tripole/dipole etc. I asked the guys ast M&K who I can't say enough about. They said that I absolutely shouldn't go with a direct radiating speaker. They reccomended getting the column surrounds or getting a tripole speaker and placing it on the floor. I have a loveseat at the back of my room for the seating area. I was going to put the speakers right behind the rear row and have the speakers slightly above the ear level of the back row. Does anyone have any experience or advise on this situation? I really would appreciate some help. I am finally making good progress.[​IMG]
     
  2. John S

    John S Producer

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    I have had success lately with pointing direct radiating speakers up like in the center sort of, against a back wall with 7.1 in such rooms.

    This actually works well also for then placing the side surrounds against the same back wall pointed forward, placed in the corners.

    I find more often then not there is no room to place side surrounds in such a room. This config not only allows it, but seems to maintain accurate steering even.
     
  3. rob-h

    rob-h Second Unit

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    The best surrounds I have ever heard are the Axim qs8's. I had direct radiating speakers in a 6.1 config that sounded very good............until I upgraded to the qs8's!! I run them as both side and rear surrounds. They make an unbelievable diffrence. Who needs dipole or bipole when you can have quadpole?[​IMG]
     
  4. John Menoni

    John Menoni Stunt Coordinator

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    Thanks guys. So you both reccomend multi directional speakers in general. Do you think it would sound good if I placed a tripole or a dipole on the back wall over the rear seating area? I'm using M&K SS-150 dipoles for the side surrounds.
     
  5. John S

    John S Producer

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    Hmm, I'd match the side surrounds no matter what.

    I had a different vision on a new install on this, where you were deciding if direct radiating speakers would work at all.


    dipole is more than fine in this install, but I'd still try to match the side surrounds.
     
  6. John S

    John S Producer

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    PS: I was just giving an alternate view of how direct radiating speakers can still work well in a room such as this in general you know. [​IMG]
     
  7. John Menoni

    John Menoni Stunt Coordinator

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    Hey John. I was origionally going to use direct radiating speakers for the back left and right with the dipoles for the surrounds. I asked a technician at M&K and he told me to either go with a 5.1 system with just the dipole surrounds or a 7.1 system with dipole back surrounds that face up like M&Ks column surrounds. He said that the direct radiating speakers with the dipoles on the sides would sound too strong. Unfortunately I'm over budget on my speakers and I don't want to spend the money on the column surrounds. I was thinking of taking a dipole speaker and placing it directly behind the rear seating area on a stand and pointing the dipole speaker up in the air to simulate the column surround. I'm waiting for his reply. I am just going to try and get as many opinions as possible before I decide to go with direct radiating or multi directional speakers for the back surrounds.
     
  8. John S

    John S Producer

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    dipole speakers would be fine for this situation.

    Better than direct radiating speakers for sure.

    But it can be done with some accuracy with direct radiating speakers as well. I've encountered a lot of different rooms and decor requirements as well, sort of getting easier to know what works best, what works at all, and what just plain doesn't work.

    Funny because all my years of pro sound experience, really did not apply to the home theater rehlm, I had to learn it through experimentation more or less. , especially living/family rooms, they are tough environments to start with.
     
  9. MikeLi

    MikeLi Supporting Actor

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    So I guess I am not following most of you. I too am in the same boat wanting to step up to 7.1. I have dipoles on the sides but only a foot or two behind the seating area. Is it better to add the backs on the floor facing up or up above facing down and just trim them down to cover for being so close or is it even worth doing it?
    Thanks
     
  10. John S

    John S Producer

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    If you use matching dipoles, place them at center back, it should be fine. Only direct radiating speakers would ever require being pointed up.
     
  11. MikeLi

    MikeLi Supporting Actor

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    I dont have anything yet for the backs.. Just wondering since seating is so close to the back wall if its worth going from 5.1 to 7.1 and how to do it the best. I have a huge drape behind the seating area which has a wide flat valance to it about 8-9 " out from the wall and I was thinking of putting up some there just to check it out and maybe tilt them somewhat downward or is the floor better or should I just bag the whole 7.1 idea. I have dipoles on the sides so I know I need direct radiators for the back if I do it. Thanks
     
  12. rob-h

    rob-h Second Unit

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    You dont "NEED" to have direct radiators for the back. Dipoles will work well also. They just tend to be more expensive.
     
  13. John Menoni

    John Menoni Stunt Coordinator

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    Mike, My rear seating area has hardly any room behind it as well. I was all set to use direct radiating speakers for the rear but a technicican at M&K strongly advised me not to. He says that because the speakers are so close to the rear row, the sound would literally go over there head. According to him, this would happen with a dipole as well if the dipole is placed over the listeners head. He reccomended using a column surround which fires directly up in the air and has other speakers on the sides creating a dipole effect. I told him that I can't possibly buy a set of column speakers and I thought of placing a regular set of dipoles directly behind the rear seating area and point them up. He said that this should work well. His first reccomendation was to just stick with the 5.1 and not to bother with 7.1 so I know he isn't just trying to get me to buy more speakers. M&K has always gone above and beyond the call of duty to help out it's customers in my opinion. They have answered a million questions patiently and thoroughly. Right now I'm leaning toward buying a very reasonable priced dipole and pointing them up.
     
  14. John S

    John S Producer

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    I understand you don't have room back there, but dipoles really go a long way to making this a non factor in my experiences with them. The trade off with them is the fact you do not get the same sort of precise steering either, but in such a situation where there is limited room be it your seating rests against the side walls or the back walls, dipole on up to 360 degree speakers are the desired speaker for that application.

    With direct radiators in such a room, you generally put one in each back corner, then the two 7.1 rears back and sort of center and pointing up.
     
  15. rob-h

    rob-h Second Unit

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    John Menoni regular Dipoles titled towards the second row would work fine for you as well. Dipoles in that case would be bouncing the sound off the rear and back of the side walls. Since the null would be pointed at the back of the listeners head, nothing would go over their head.
     
  16. John S

    John S Producer

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    Yep.. exactly what rob-h said....

    Dipoles interact with rooms vastly differently than direct radiating speakers. Can solve or vastly improve most placement issues/problems in general.
     
  17. MikeLi

    MikeLi Supporting Actor

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    I did some talking around and checking as well. My seating is so close to the back wall and I have great side dipoles I think I am just going to stick with 5.1, it's done me great for many years and should for more to come when I can get a new room or something... Thanks all.
     
  18. John S

    John S Producer

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    I think that is a wise choice.. A well calibrated, accurate and better quality 5.1 is better than a lesser or hampered by odd speaker placement 6.1 or 7.1 system every time in my book.
     
  19. John Menoni

    John Menoni Stunt Coordinator

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    I am defintatly going with dipoles as stated in my previous post. The only problem now is figuring out the best placement. Right now because of the M&K tech's advise, I'm leaning toward placing the dipoles behind the rear loveseat or just next to the rear seat and pointing the dipoles upward. This would closely simulate the most ideal acoustic situation.

    Mike, you might be making a wise choice. M&K took into account all the dinensions of my room and even made a diagram of my room with the placements of the speakers and seating. At first he reccomended just sticking with a 5.1 system.
     
  20. rob-h

    rob-h Second Unit

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    You point direct radiating speakers upwards to difuse the sound by bouncing it off the cieling. Dipoles by their very nature difuse the sound because of where the drivers are placed. They dont need to be pointed up as there is no driver in the null area that will be facing the cieling. The drivers will still be bouncing the amjority of the sound off the back and side walls.
     

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