Voices coming from my new sub

Discussion in 'Home Theater Projects' started by Jordan_Brulotte, Sep 25, 2004.

  1. Jordan_Brulotte

    Jordan_Brulotte Stunt Coordinator

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    I just completed my tempest sub with this amp creativesound.ca/details.php?model=SUB250RF

    I have set the crossover to ~90hz. However, I can still make out voices and lyrics in the music I am playing, with only the sub playing. Is this normal? I didn't think harmonics in human voices could extend that low.
     
  2. James W. Johnson

    James W. Johnson Screenwriter

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    Cross it over lower, stuff the box more.
     
  3. Jordan_Brulotte

    Jordan_Brulotte Stunt Coordinator

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    wont stuffing it more make it sound a bit muddier? I am playing the sub temporarily off of my computers sound card. The sub will be used for HT, so it will eventually be hooked up to a receiver. Will using the LFE crossover on the receiver help at all, by "doubling" the protection?
     
  4. ThomasW

    ThomasW Cinematographer

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  5. Jordan_Brulotte

    Jordan_Brulotte Stunt Coordinator

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    I am still learning so please don't mind my questions.

    The lower end of the voices seem to be getting past the crossover. I thought that stuffing the cabinet would prevent high frequency resonance in the cabinet. I already have lined the inside with about an inch or so of polyfill. Should I stuff it full?
     
  6. ThomasW

    ThomasW Cinematographer

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    Normal crossovers aren't brickwall filters, they usually roll-off (attenuate) the frequencies over an octave or two depending on the slope
     
  7. Jordan_Brulotte

    Jordan_Brulotte Stunt Coordinator

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    My cabinet is ported with 2 4"x15" ports. Internal volume is ~265 litres, made of 3/4 MDF, with bracing almost every 8 inches.

    Suffice to say the cabinet weighs A LOT.

    Also, the bass at soem points sounds somewhat muddy, and doesn't "punch" as hard as I want. Right now WinISD tells me that my group delay at 20hz is 33ms, and I know this is high. Would increasing the port length, to decrease the tuning frequency and group delay, result in tighter bass? Is this a good idea?
     
  8. ThomasW

    ThomasW Cinematographer

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    How many problems are we going to solve in this thread?

    Before you make any decisions as to the performance of the sub, you need to measure the in-room frequency response.
     
  9. Wayne A. Pflughaupt

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    What is your crossover slope? I have mine at 90Hz, but with 24dB/octave slopes, and I rarely hear voices from the sub.

    Regards,
    Wayne A. Pflughaupt
     
  10. Jordan_Brulotte

    Jordan_Brulotte Stunt Coordinator

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    Sorry, I did not mean to annoy with a multitude of questions. Thanks.
     
  11. ThomasW

    ThomasW Cinematographer

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    The crossover is variable from 40-160Hz. Where do you have yours set?
     
  12. Jordan_Brulotte

    Jordan_Brulotte Stunt Coordinator

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    ~90hz
     
  13. James W. Johnson

    James W. Johnson Screenwriter

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    I doubt the slope is any better than 12dB/octave but even still you should not be able to hear voices....just cross it over @ 50hz and be done with it. [​IMG]

    Have you not tried this??? Try it and get back to us. [​IMG]
     
  14. al lout

    al lout Stunt Coordinator

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    I've just checked my tempest out when I saw this thread today. I'm too hear voices coming out of my tempest. I tried to turn the crossover all the way down to 40hz and still hear voices from the sub. I'm running it on the yamaha htr 5560 which as the built-in crossover at 90hz. BTW, my sub is a sealed sub with the PE 250W plate amp. I did stuffed a lil more than recommended. Any clue why I still can hear voices eventhough the plate amp crossover is as low as 40hz? Thanks!

    Al,
     
  15. ThomasW

    ThomasW Cinematographer

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    Yes. Crossovers are not brickwall filters. They roll-off the frequencies at a specific rate per octave. This means that there are some higher frequencies that get though.
     
  16. Allen Ross

    Allen Ross Supporting Actor

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    I have noticed on my PE 250W amp that the cross over is defeated if i use RCA inputs, but if i use my mains as inputs and then out to my mains, the cross over will have affect.

    Also can't hurt to get a BFD and set your own slope as high as you want.
     
  17. bernard&*

    bernard&* Stunt Coordinator

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    Mine too..I build 122L sealed tempest even I turned the x'over to 40hz and my receiver to 60hz I still heard voice anyway to defeat this.Also I stuffed it with plyfill into two standard size pillow.Thanks God Bless
     
  18. Greg Yeatts

    Greg Yeatts Second Unit

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    Hmmm... Voices from your subwoofer. You may have over-looked the obvious. If you turn your subwoofer off can you still hear the voices? If you still hear those voices and the sub is off, it may be time to seek more complicated professional solutions. [​IMG]

    All joking aside, I think it may be the crossover. But you stated you hear the voices when only the sub is playing. Does it distract you when your other speakers are playing with the sub? If you have a front firing sub you could fire the sub towards a wall.
     
  19. Paul_C

    Paul_C Stunt Coordinator

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    I built a 155L Shiva with the same PE250 W plate amp and have the same problem. I replaced the sub with a PSB Subsonic 7 and didn't hear any voices. It's too bad I had to give my brother his Subsonic back.

    After reading the responses to the initial question I believe Thomas is right, in that the crossover in the plate amp isn't the best one in the world, especially using the rca input. I will have to test Allan's idea of using the mains in/out to see if that is any better.

    Regards,

    Paul.
     

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