50 Hz spike / causes?

treitz3
treitz3 Posts: 19,029
edited June 2008 in Subwoofer Hookup & Bass Management
I am getting a 50 Hz spike that's high enough to have an audible distraction coming from my sub woofer. What I would like to know from those in the know is...

1 - what are the possible causes?
2 - what can I do to improve the spike without resorting to a graphic EQ continuously in the loop?
3 - Can I change the "Q" in the parametric EQ via the Velodyne SMS-1 to help with this spike?

I had the same thing with the last sub I had which was the Polk PSW1000 and I currently have the spike with the VMPS larger sub powered by a M1.0t, fed by the SMS-1 as well. 12x14' room, V shaped ceilings running the length of the room, VMPS on marble tile over a rug, placed in the left corner of the rig. Here's a couple of pic's....

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All equipment must remain on this wall due to space constraints, so I may have no choice but to put up with it. I don't know, that's why I'm asking those in the know.

I have experimented with a 12db drop at 50Hz on the graphic EQ as well as a drop as far as the SMS-1 will allow and the spike is still effecting a flat frequency curve. Before I go **** with anything, does anybody have any advice?
~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
Post edited by treitz3 on
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Comments

  • ben62670
    ben62670 Posts: 15,969
    edited March 2008
    Room gain can throw things off. If the sub has a parametric setting you may be able knock that bump out. Room placement could certainly help, but I have shared the same space limitations.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • wallstreet
    wallstreet Posts: 1,405
    edited March 2008
    acoustic room treatments should help tame the spike. My B&K has a "notch filter" that allows me to treat the same problem in my room. But I guess that's kind of an equalizer.
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  • Systems
    Systems Posts: 14,873
    edited March 2008
    If it is a narrow spike it may be a room mode resulting from the corner placement of the sub.If you can't move the sub to a different location then yes using a parametric EQ set to its narrowest bandwidth and appropriate amount of attenuation should improve matters.I have a similar problem around 50 hz in my room and using a single band of parametric EQ to notch out the peak does the trick.


    Edit.Oops sorry Ben I should have read your post before typing ,you already covered it.
    Testing
    Testing
    Testing
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  • treitz3
    treitz3 Posts: 19,029
    edited March 2008
    Is a spike 50Hz common?
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
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  • Systems
    Systems Posts: 14,873
    edited March 2008
    treitz3 wrote: »
    Is a spike 50Hz common?
    It depends on the the dimensions of the room and the location of the speaker there in.Google room modes and you should find some good info.
    Testing
    Testing
    Testing
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  • VR3
    VR3 Posts: 28,644
    edited March 2008
    Brian has an adjustment you can do to the Larger to adjust for things like this

    Give him an email.
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • TNRabbit
    TNRabbit Posts: 2,168
    edited June 2008
    Tom, were you able to fix the spike? Also, I think it is a VERY BAD IDEA to place your sub amp ON the sub.....
    TNRabbit
    NO Polk Audio Equipment :eek:
    Sunfire TG-IV
    Ashly 1001 Active Crossover
    Rane PEQ-15 Parametric Equalizers x 2
    Sunfire Cinema Grand Signature Seven
    Carver AL-III Speakers
    Klipsch RT-12d Subwoofer
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  • george daniel
    george daniel Posts: 12,096
    edited June 2008
    take the grills off of those tylers' ;)
    JC approves....he told me so. (F-1 nut)
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  • Early B.
    Early B. Posts: 7,900
    edited June 2008
    TNRabbit wrote: »
    Also, I think it is a VERY BAD IDEA to place your sub amp ON the sub.....

    Why?
    HT/2-channel Rig: Sony 50” LCD TV; Toshiba HD-A2 DVD player; Emotiva LMC-1 pre/pro; Rogue Audio M-120 monoblocks (modded); Placette RVC; Emotiva LPA-1 amp; Bada HD-22 tube CDP (modded); VMPS Tower II SE (fronts); DIY Clearwave Dynamic 4CC (center); Wharfedale Opus Tri-Surrounds (rear); and VMPS 215 sub

    "God grooves with tubes."
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  • TNRabbit
    TNRabbit Posts: 2,168
    edited June 2008
    Early B. wrote: »
    Why?

    ~V-I-B-R-A-T-I-O-N~:eek:
    TNRabbit
    NO Polk Audio Equipment :eek:
    Sunfire TG-IV
    Ashly 1001 Active Crossover
    Rane PEQ-15 Parametric Equalizers x 2
    Sunfire Cinema Grand Signature Seven
    Carver AL-III Speakers
    Klipsch RT-12d Subwoofer
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  • Early B.
    Early B. Posts: 7,900
    edited June 2008
    That VMPS sub is built like a tank and it ain't gonna vibrate. And even if it does, so what? Most subwoofers use plate amps and the vibration is not a major factor, so placing an external amp on top of a sub will be even less of an issue.
    HT/2-channel Rig: Sony 50” LCD TV; Toshiba HD-A2 DVD player; Emotiva LMC-1 pre/pro; Rogue Audio M-120 monoblocks (modded); Placette RVC; Emotiva LPA-1 amp; Bada HD-22 tube CDP (modded); VMPS Tower II SE (fronts); DIY Clearwave Dynamic 4CC (center); Wharfedale Opus Tri-Surrounds (rear); and VMPS 215 sub

    "God grooves with tubes."
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  • engtaz
    engtaz Posts: 7,663
    edited June 2008
    Wabbit is a friend of Tom's.

    engtaz
    engtaz

    I love how music can brighten up a bad day.
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