Why does my center speaker sound bassy?

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_nerd
_nerd Posts: 54
Hi all,

I have a Polk Audio LSiC center speaker. Whenever someone in a movie or TV show talks while the system is at a high volume, the center speaker emits quite a bit of bass at the lower frequencies of someone’s voice.

Speaker configuration:
80Hz front, center and rear
120Hz LFE
0dB front, center, rear, and sub
Sound mode: direct
No room calibration

I don’t use calibration because (to my ears) the speakers sound fuller without it. I’m using a Onkyo TX-NR809 for processing, and a Rotel RMB-1095 amplifier to drive the speakers.

Best Answers

  • F1nut
    F1nut Posts: 49,802
    Answer ✓
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    You absolutely need to run the calibration program.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • Clipdat
    Clipdat Posts: 12,607
    Answer ✓
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    Slide the center channel speaker forward so that it doesn't have the surfaces of the amplifier and receiver in front of it. Ideally you don't want any immediate surfaces right in front of it for the sound to reflect off of.
  • F1nut
    F1nut Posts: 49,802
    edited April 2019 Answer ✓
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    A couple of things. Your center appears to be sitting on DVD cases instead of one solid shelf, not good. The gap between the AVR and the amp is acting like a megaphone for the sound coming out of the power ports.

    Can you put the AVR and amp on the lower shelves? If so, put the center on the top shelf and lower the TV as it's too high anyway.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

«1

Answers

  • _nerd
    _nerd Posts: 54
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    F1nut wrote: »
    You absolutely need to run the calibration program.

    Oh alright, I’ll run it in a moment. I stopped using calibration years ago because the speakers sound canned and compressed with it enabled.
  • Clipdat
    Clipdat Posts: 12,607
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    Agreed, bust out that mic, have the room as quiet as possible and run that calibration program.

    There ought to be a fairly substantial difference/improvement afterwards.
  • _nerd
    _nerd Posts: 54
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    Ok I ran it. It set my front 3 speakers to 40Hz, detected that I didn’t have rear speakers (I don’t have any yet), set the center speaker to -3.0dB, sub to -2.0dB and other settings.

    I had to set the 3 fronts back to 80Hz because my sub didn’t appear to output any bass. Setting the fronts to 80Hz brought the sub back to life, and I left the calibrated dB settings alone. I’m having the same experience with the center, having a strong bassy resonance during during vocal dialogues.

    Should I go back to a dual 6.5” center speaker? Would adding sound treatment panels to the wall help? The center speaker is not in an enclosed area.

    t94f8kagbzss.jpeg
  • _nerd
    _nerd Posts: 54
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    Ok as I’m watching TV more post calibration with the center at -3.0dB, the center does sound less bassy but still it still has a significant resonance.

    Would setting the center at a lower dB help some more? Is there a such thing as EQ per channel? I believe I had that type of granularity on a Marantz AV7704mkii I owned previously.
  • pitdogg2
    pitdogg2 Posts: 24,579
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    Manually drop the bass some in the GUI EQ settings. It may make voices sound strange so be careful. You also may be able to up the center to 120hz setting. Some receiver/processors will allow this some not.

    Like @Clipdat said and I cannot stress enough that you need a very dead quiet area while doing it. Things as unlikely as furnaces kicking on can affect the outcome. I chased my tail for days trying to figure out a problem once. Mine was a very low water trickle sound from my fish room (barely audible). Some of those mics are veerrry sensitive.

    Dead quiet is best.
  • WLDock
    WLDock Posts: 3,073
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    You are for sure getting peaks in the response. Like others have said, run cals from as many locations as your software will allow. Run some a few inches to the right or left of the main mic position also.
    2.2 Office Setup | LG 29UB55 21:9 UltraWide | HP Probook 630 G8 | Dell Latitude | Cabasse Stream Amp 100 | Boston Acoustics VS 240 | AUDIORAX Desk Stands | Mirage Omni S8 sub1 | Mirage Omni S8 Sub2
  • _nerd
    _nerd Posts: 54
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    Thank you both for the tips. Setting the center channel floor to 120Hz and overall bass to -4.0dB, I still have a strong peaks from the center speaker.

    This is driving me nuts. I’ve owned the Polk CSi5, CSi40, and CS400i center speakers and never experienced this “peak” effect before. I will run calibration again in several positions at and around my listening areas.
  • _nerd
    _nerd Posts: 54
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    Update:

    Setting the center crossover to 150Hz made a bigger difference than 120Hz. I get the sense that the low end falls off sharply just before the the perceptible “peak” I experienced prior to setting it to 150Hz.

    I’ve never had to set a crossover point above 80Hz before. Also, I just found a menu option for EQ settings and there is an EQ for each channel. Should I lower the crossover point for the center channel back to 80Hz and make adjustments to the EQ for that channel instead?
  • pitdogg2
    pitdogg2 Posts: 24,579
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    could you be getting a reflection from in front from how you have it set up?
  • _nerd
    _nerd Posts: 54
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    Reflection from the wall? I was thinking this could be the case. Would putting sound treatment on the wall be a good troubleshooting step?

    To rephrase something I’ve said earlier, I did have an issue like this in the past with another dual 5.25” center speaker many many years ago. It was a Polk CSi30. I hated that speaker so much - it was a temporary center between two of the bigger Polk center speakers I mentioned previously. I had a feeling in the back of my mind when I bought the LSiC after placing the CSi5 with a new owner that I would experience this “peak” problem again.

    Maybe I should go back to a bigger center speaker. Is the LSiM706c any good?
  • pitdogg2
    pitdogg2 Posts: 24,579
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    no I was thinking off the amp and receiver. Then you have that void in between those.
  • _nerd
    _nerd Posts: 54
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    jft2987m8b28.jpeg

    There is 7.5” of space between the back of the center speaker and the wall, and equipment under 4” of space in front of the center speaker, as shown in the photo.
  • ericv
    ericv Posts: 9
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    Try setting the center to “small”. It will throw a little more of the soundstage out to the fronts and the bass will go to your subs. It’s worth a shot.
  • ericv
    ericv Posts: 9
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    Also, if your center channel is a ported speaker, try inserting some foam into the port. It will tighten up the bass.
  • _nerd
    _nerd Posts: 54
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    Thank you very much for the tips, @ericv. I can’t find the setting to set any speakers to large/small. I only have crossover & EQ options for each channel. The speaker does have two PowerPorts in the back. I will look into inserting foam into the ports from the inside.
  • BlueFox
    BlueFox Posts: 15,251
    edited April 2019
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    _nerd wrote: »
    Ok I ran it. It set my front 3 speakers to 40Hz, detected that I didn’t have rear speakers (I don’t have any yet), set the center speaker to -3.0dB, sub to -2.0dB and other settings.

    I had to set the 3 fronts back to 80Hz because my sub didn’t appear to output any bass. Setting the fronts to 80Hz brought the sub back to life, and I left the calibrated dB settings alone. I’m having the same experience with the center, having a strong bassy resonance during during vocal dialogues.

    Should I go back to a dual 6.5” center speaker? Would adding sound treatment panels to the wall help? The center speaker is not in an enclosed area.

    t94f8kagbzss.jpeg

    Your center is equal to both your L/R channel speakers combined. Get some full range floor standing speakers for the L/R, calibrate the setup, and then report how it sounds.

    I had that center for years along with LSi15s for the L/R front, and never had an issue.
    Lumin X1 file player, Westminster Labs interconnect cable
    Sony XA-5400ES SACD; Pass XP-22 pre; X600.5 amps
    Magico S5 MKII Mcast Rose speakers; SPOD spikes

    Shunyata Triton v3/Typhon QR on source, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • _nerd
    _nerd Posts: 54
    edited April 2019
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    Done. Thank you for the tip. I have lowered the crossover to 120Hz for testing at this placement point.

    Edit: this response is for @Clipdat
  • _nerd
    _nerd Posts: 54
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    @BlueFox: I’m working on getting a pair of LSi9 speakers locally. I’ve been fascinated by those speakers for many years. I could obtain a pair of LSi15 but I don’t care for the built in subs.

    @F1nut: the amp weighs almost 80lbd. There is clearance for it on the shelf right underneath its current placement. I do feel I mounted the TV too high. I mounted it in a way that the horizontal center of the TV is eye level when I am standing up. Is that too high? I don’t mind relocating the components away from the top shelf, but I don’t think the lower shelves can handle 100+ pounds of equipment. When I had a SVS SB16 Ultra subwoofer, I had the amp sitting on top of it.
  • FestYboy
    FestYboy Posts: 3,861
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    Center of screen should be just above eye level while seated.
  • F1nut
    F1nut Posts: 49,802
    edited April 2019
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    If the top shelf will handle the load, so will the others. Try what I suggested as it will solve a lot of your issues.

    I like the screen with the center line just below eye level when seated. Either Arty's or my preference would be considerably better than what you have now.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • FestYboy
    FestYboy Posts: 3,861
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    Jesse, do you run multi channel for your TV, or strictly 2 ch?
  • F1nut
    F1nut Posts: 49,802
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    Multi
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • _nerd
    _nerd Posts: 54
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    @FestYboy: many thanks to you as well for the tip. I can get the middle TV just above eye level when seated.


    @F1nut: I am looking forward to moving things around tonight and lowering the TV.


    To everyone: Would the center speaker be too low in proportion to the L/R mains if I relocated it to the middle shelf of the TV stand? When the TV lowered to the more desirable height, there won’t be room on the top shelf for the center speaker. The wall mount doubles as the mounting plate for the TV + a square neck/stem to attach it directly to the TV stand, allowing the TV to swivel. Would it be better to attach the TV to the TV stand again?

    k39g30z27jry.jpeg
  • BlueFox
    BlueFox Posts: 15,251
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    The center should be at the bottom of the TV. Mine is actually a bit higher since a lot of movies are letter boxed, and for those that are full screen I rarely notice the top of the center in the picture.
    Lumin X1 file player, Westminster Labs interconnect cable
    Sony XA-5400ES SACD; Pass XP-22 pre; X600.5 amps
    Magico S5 MKII Mcast Rose speakers; SPOD spikes

    Shunyata Triton v3/Typhon QR on source, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • _nerd
    _nerd Posts: 54
    edited April 2019
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    @BlueFox: I agree. What I mean to ask is if it is ok for the center speaker to be below the L/R speakers. I tried to raise the center speaker to be as close to level with the mains as possible.

    Edit: corrected one incorrect word.
  • BlueFox
    BlueFox Posts: 15,251
    edited April 2019
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    Since my L/R speakers are towers, and on maple speaker stands, they are definitely higher than the center. The center is 99% for movie audio, so adjust it for the TV, not the other speakers.

    ebcetubvbvak.jpeg
    Lumin X1 file player, Westminster Labs interconnect cable
    Sony XA-5400ES SACD; Pass XP-22 pre; X600.5 amps
    Magico S5 MKII Mcast Rose speakers; SPOD spikes

    Shunyata Triton v3/Typhon QR on source, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • _nerd
    _nerd Posts: 54
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    88xnyr1sr2zr.jpeg

    I was able to raise the middle shelf by removing 4 screws & so on. The equipment fits perfectly on the bottom shelf and is fully supported by the 4 thick machine screws holding the bottom shelf in place. Many thanks for the tips offered tonight. I will likely re-attach the TV to the TV stand with the neck piece tomorrow instead of tonight. It looks so pretty and I remember how difficult it was to get the tv on the wall, I don’t want to pull the tv stand away from the wall tonight.

    @BlueFox: killer speakers you have there. I wanted that subwoofer for a minute. I currently have a Polk DSW microPRO 3000 & a Klipsch RSW-10 which sounds better than the 3000 despite having less than 1/3 the RMS output. I don’t use the Polk sub at all anymore.