Subwoofer Placement

Discussion in 'Archived Threads 2001-2004' started by Ronald Volkman, Oct 11, 2002.

  1. Ronald Volkman

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    I've had my PC+ 16-46 for about a week now, and it is a remarkable machine - like a "big shuddering column of air". The listening room is 19x13x8 set up diagonally with the TV in the corner, and the seats in an 'L' shape. I used to have my PW-2200 sub in the front next to the TV, but it was always a little "boomy" there due to a 40-50hz peak. A few weeks ago, I moved the PW-2200 to the rear corner after measuring with ETF and finding that the response was MUCH smoother in that corner. (I also recently got a BFD.) The sound was much better after that from all seats.

    I put the 16-46 in that same corner now and the sound is stunning throughout the room. In fact, on something like LOTR, the LFE almost "wears you out" after a while. (I said almost:^) The problem is, when sitting in the seat where the sub is about 7 ft. directly to your right side, you can feel the sound against your right side. It's not the same as localizing the sub with your ears (80hz x-over), it's actually feeling the sound against the right side of your face and body. This didn't happen with my PW-2200. I measured a 20hz peak from there and reduced it by 4-5db with the BFD. (I never in my life thought I'd need to REDUCE the 20hz ouput of one of my speakers.)

    I'm now thinkin of putting the 16-46 behind the TV in the corner, but even before trying it, I'm concerned it will shake the TV apart. Does anyone put their sub behind a TV (Toshiba 55") in the corner?

    Ron
     
  2. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    That sense of pressure on only one sounds sounds like a phase issue of bass cancellation occuring on one side of the listener position.

    Have you tried adjusting the phase in relationship to the mains at the crossover frequency?

    Putting a TV in the corner where high pressure levels occur isn't always good, especially if it's the same corner a subwoofer is. The sub isn't shielded so I'd make sure it has some distance from the tube.

    A 20hz spike? Your room's lowest standing wave is the 30hz first order length and that should be causing a dip from the middle of the room. I wonder what could be the cause of a 20hz spike...
     
  3. Ronald Volkman

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    Chris,
    I didn't try the phase, and I'm not convinced that's it, but I will try it out. Also, I did try the sub behind the TV, and it was just too much. The front of the set vibrated and I didn't want all of that going through the set's chassis. The room actually opens out to another room, so that mey be the reason for the 20hz peak.
    See picture here:
    My HT Room
    When the sub is at S2, it sounds great from L1, but at L2, you are ofter aware of the sub. I moved it over to S3 today, and it seems to blend much better.
    Ron
     
  4. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    S3 seems bad for anyone on the L1 couch though.

    Have you considered a different configuration?

    Perhaps the TV against the left middle wall with the sub in the top left corner. But then you'd have to move the seats around, but it would be easier to place surrounds and can provide a bigger sweet spot.

    If you can't rearrange, then I remember THX and Dolby recommend against subwoofer placement that's to the left or right of the listening position. Rear placement can be even worse.

    How about moving the sub along one of the front walls, it will still gain some SPL just not as much from a corner placement. You may get better results from more of the seating positions this way.
     

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