Center Speaker Radiation

CTS
CTS Posts: 8
edited February 2013 in Speakers
I have a large flat panel Plasma TV over the fireplace and the current wall mounted center speaker (7"H) is partially blocked by the bottom of the TV so only about 1/2 the speaker is exposed. The distance from the mantle to the bottom of the TV is 5"H. In addition the bottom grill is flush with the 6" D fire place mantle. This configuration I believe is the cause of my center speaker dialog being muddled and difficult to understand with soft voices. Technically I believe the geometry of the speaker placement exit is altering the speakers exit impediance and in addition there are reflections off the mandle ledge and bottom of the TV.

My proposed solution is to purchas a TL3 (if they are ever in stock) or TL2 center speaker sound bar. I could set this on the mantle or mount it inside the wall just like the current large speaker. (It will fit with no struts present)

Here are my questions:
1) Do you think the single channel speaker bar is a good solution?
2) Do you think mounting flush inside the wall is a good idea? If so, where can I get a long narrow grill to put over the dry wall?
3) What if I used a multi-speaker sound bar and looped the signal through the TV so all channels would be present from the sound bar as well as my existing surrond sound 5-speaker system (with the old center deactivated)?
4) Do you have any other suggestions to fix this problem with the center speaker dialog?

Thanks.
Post edited by CTS on

Comments

  • michael1947
    michael1947 Posts: 775
    edited January 2013
    Go back to the drawing board. Your plasma is likely too high for excellent viewing if placed above the fireplace. Sometimes it is not easy to get it "right" and plopping a large tv above a fireplace is not "right." If your center is partially covered it will not sound "right" and you cannot fix it. Replace the center with some skinny little speakers or sound bar, maybe even some Bose. I would then limit that rig to watching the 6 o'clock news and Leno. If you want it "right" go to another wall, IMHO.
    Main Family Room: Sony 46 LCD, Sony Blue Ray, Sony DVD/VCR combo,Onkyo TXNR 708, Parasound 5250,
    Polk SDS-SRS with mods, CSI 5 center + Klipsch SC2, Polk RT2000P rears, Klipsch KG 1.5's sides, Polk Micro Pro 1000, Polk Micro Pro 2000, Polk SW505, Belkin PF60, Signal Cable Classics,Monster IC's, 2 15 amp circuits & 1 20 amp circuit.

    Living Room: Belkin PF60, Parasound HCA2200, MIT ProlineEXP balanced IC's,Emotiva XDA-1 DAC/Pre,Emotiva ERC2 transport,MIT AVT2, Polk LSI 9's.
  • tommyt21
    tommyt21 Posts: 685
    edited January 2013
    Go back to the drawing board. Your plasma is likely too high for excellent viewing if placed above the fireplace. Sometimes it is not easy to get it "right" and plopping a large tv above a fireplace is not "right." If your center is partially covered it will not sound "right" and you cannot fix it. Replace the center with some skinny little speakers or sound bar, maybe even some Bose. I would then limit that rig to watching the 6 o'clock news and Leno. If you want it "right" go to another wall, IMHO.
    He has duplicate threads I said the same thing
    Living Room
    Fronts: RTi A7's
    Center: Csi A6 VR3 "Fortress Plus"
    Front Heights: Rti A1
    Surrounds: Rti A3
    Sub: HSU VTF-2 MK4 Damn this is a good SUB
    Pioneer Pioneer Elite: SC-35-> Emotiva XPA-3
    TV: Lg LW6500 55" Passive 3D
    Blu-Ray Panasonic BD 210
    XboX 360 Slim/Kinect

    Acoustimac red suede panels
  • michael1947
    michael1947 Posts: 775
    edited January 2013
    For tommyt21 i just noticed you have a modified center, vr3 fortress plus. How's that working out. I am always monkeying around with my center to get my dialog up...about to go back to a dual Klipsch center with higher efficiency.
    Main Family Room: Sony 46 LCD, Sony Blue Ray, Sony DVD/VCR combo,Onkyo TXNR 708, Parasound 5250,
    Polk SDS-SRS with mods, CSI 5 center + Klipsch SC2, Polk RT2000P rears, Klipsch KG 1.5's sides, Polk Micro Pro 1000, Polk Micro Pro 2000, Polk SW505, Belkin PF60, Signal Cable Classics,Monster IC's, 2 15 amp circuits & 1 20 amp circuit.

    Living Room: Belkin PF60, Parasound HCA2200, MIT ProlineEXP balanced IC's,Emotiva XDA-1 DAC/Pre,Emotiva ERC2 transport,MIT AVT2, Polk LSI 9's.
  • tommyt21
    tommyt21 Posts: 685
    edited January 2013
    For tommyt21 i just noticed you have a modified center, vr3 fortress plus. How's that working out. I am always monkeying around with my center to get my dialog up...about to go back to a dual Klipsch center with higher efficiency.
    Its worth its weight in gold. Also try decoupling your center I use acoustic foam, same concept as a subdude. I never, repeat never have issue with dialouge. In fact after all my tweaks we keep the volume much lower than before because of the clarity. My center is definetly the star of the system
    Living Room
    Fronts: RTi A7's
    Center: Csi A6 VR3 "Fortress Plus"
    Front Heights: Rti A1
    Surrounds: Rti A3
    Sub: HSU VTF-2 MK4 Damn this is a good SUB
    Pioneer Pioneer Elite: SC-35-> Emotiva XPA-3
    TV: Lg LW6500 55" Passive 3D
    Blu-Ray Panasonic BD 210
    XboX 360 Slim/Kinect

    Acoustimac red suede panels
  • CTS
    CTS Posts: 8
    edited January 2013
    The TV can not be moved up. It is at the ceiling now with only room to allow it to be lifted off its mount. Moving the TV up is not an option.
  • michael1947
    michael1947 Posts: 775
    edited January 2013
    tommyt21 wrote: »
    Its worth its weight in gold. Also try decoupling your center I use acoustic foam, same concept as a subdude. I never, repeat never have issue with dialouge. In fact after all my tweaks we keep the volume much lower than before because of the clarity. My center is definetly the star of the system
    Thanks for the info. I'm about to move my big speakers out and return my RTI-A9's and the rest of that system to see how it works out, kind of tired of big sound on all of the corners and squinting to hear the dialog....maybe just an AVR setting but things are so complicated, just don't know. Thanks again.
    Main Family Room: Sony 46 LCD, Sony Blue Ray, Sony DVD/VCR combo,Onkyo TXNR 708, Parasound 5250,
    Polk SDS-SRS with mods, CSI 5 center + Klipsch SC2, Polk RT2000P rears, Klipsch KG 1.5's sides, Polk Micro Pro 1000, Polk Micro Pro 2000, Polk SW505, Belkin PF60, Signal Cable Classics,Monster IC's, 2 15 amp circuits & 1 20 amp circuit.

    Living Room: Belkin PF60, Parasound HCA2200, MIT ProlineEXP balanced IC's,Emotiva XDA-1 DAC/Pre,Emotiva ERC2 transport,MIT AVT2, Polk LSI 9's.
  • CTS
    CTS Posts: 8
    edited February 2013
    This is a duplicate to the question in the "Test" forum. I keep forgetting to switch to the "Speaker" forum to post my question/comment. Here it is:

    The concern others have expressed about viewing the TV is not an issue. I have a new Panasonic Plasma 3-D TC-65VT50. The TV is mounted and tilted above a gas-burning fire place that is very well isolated from the heat or reflections (the mantel is perhaps 2-feet above the fireplace opening. It is easy and comfortable to view the TV from any angle in the room. The TV viewing is not the issue.

    The issue is the previously built in surround sound system, which would be a major project to rewire and relocate. The location of the theater system is ideal right now. The Panasonic Plasma 3-D TC-65VT50 is very large (65" diagonal). Its height is 35.1" and it is 2" thick. This distance from the top of the 6" mantel to the ceiling is 42.5". That is there is theoretically 7.4" space available. Give some slop-space it is probably more like 6.75". I believe that to play it safe and for circulation, the TV should be perhaps 1" down from the ceiling. So the distance from the mantel to the bottom of the TV is 5.75"

    In addition, as I mentioned above the mantel is 6" deep. Cutting out the drywall there is an addtional 5.5" until one hits the fireplace brick hidden behind the drywall. That is the total theoretical depth for a speaker could be as much as 11.5" by extending out of the drywall to the edge of the mantel. The speaker width can be very wide as the dry wall space behind the TV contains no struts.

    So in summary, I am looking for suitable center (single channel) speaker that is LESS THAN 5.75H x 11.5D x ???W, if the speaker sits on the mantel. If the speaker is wall mounted (such as the current speaker that is too big), then the depth should be less than 5.5"D including the grill.

    Can you recommend some good quality candidate speakers that fit within these envelopes?
  • CTS
    CTS Posts: 8
    edited February 2013
    Tommyt12, I am intriged by you comment: "Also try decoupling your center I use acoustic foam, same concept as a subdude. I never, repeat never have issue with dialouge. In fact after all my tweaks we keep the volume much lower than before because of the clarity. My center is definetly the star of the system" Can you elaborate (i.e., translate). 1) What acoutic foam, are you talking about that spray stuff or the foam pads)? 2) What is a "subdude"?
  • cnh
    cnh Posts: 13,284
    edited February 2013
    Welcome to Club Polk!

    Radiation is a "dangerous" thing. I suggest some lead shielding, at the very least! And stay away from the speaker if you can; the farther back the better!

    Sorry, I couldn't resist!

    Plenty of advice above. Lower the screen, speaker above and below screen as your center(s) might work! A common solution around here!

    cnh
    Currently orbiting Bowie's Blackstar.!

    Polk Lsi-7s, Def Tech 8" sub, HK 3490, HK HD 990 (CDP/DAC), AKG Q701s
    [sig. changed on a monthly basis as I rotate in and out of my stash]
  • CTS
    CTS Posts: 8
    edited February 2013
    Not to worry. I have lead poncho I got from an Xray technician. Maybe that's the problem?

    Seriously, I am starting to think Tommyt12 is on to something. Namely, acoustic-structural interaction causing reverbs in the 100 to 4K Hz range that distort the dialogue. Isolating the center speaker might be a remedy if indeed this is the cause. The question is how to acoustically isolate the center speaker, which is a challenge especially with a wall mounted center.