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When you say flat you mean.....

Discussion in 'Home Cinema Speakers' started by Brad_Porter, Aug 23, 2002.

  1. Brad_Porter

    Brad_Porter
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    I was reading Jase's mini review on his new Velodyne sub and I hear people asking questions like 'is it as flat as your last sub' etc.

    What exactly does 'flat' mean?

    Jeez. Have I got a lot to learn. ;)
     
  2. Jase

    Jase
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    Hi Brad

    They were referring to the frequency response of my sub in my "room". Have a look at this thread Subwoofer Measurements

    Should explain everything.:)

    Cheers
     
  3. Brad_Porter

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    Jase - (Hows it going by the way? Cool I hope?)

    But what does it all mean! There are guys there with peaks and dips and mountain like pictures! Whats the idea? To get a flat line on the graph?? When theres a peak or a dip, what does that sound like if you are in the room?

    Sigh.
     
  4. Ian J

    Ian J
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    With respect to jase, that thread will confuse most people.

    Flat means that the output in decibels will be constant over the whole frequency range.

    Most subs if not correctly set up will output +2Db at 35Hz and -1 at 30Hz and -6Db at 20Hz (just matematical examples & not real figures)
     
  5. Ian J

    Ian J
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    Mine has peaks and troughs all over the place and sounds great. If you have a highly trained ear you may notice something but not the average punter.

    You can do something to flatten it out by moving the sub around and retesting but many of us can't do that as there aren't always options in a room about where to park such a large beast.
     
  6. Jase

    Jase
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    Fine here.:)

    A peak means that the room/sub or both is boosting that particular frequency whereas a dip means you have a drop off at that frequency. Ideally you would have a flattish response so that the overall bass sound is smoother.

    A peak would mean that you´ll be hearing more of that frequency and overpowering the rest of the frequency range.

    Bear in mind that if the sub sounds good to you and your ears it doesn´t matter what the graph looks like. As long as you´re happy with the sound.:)
     
  7. Brad_Porter

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    Thanks guys - learning something new everyday....

    Cheers
     
  8. Couch Potato

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    Then you could always confuse the situation by not having a flat response but allow for a "room curve" :devil:

    Steve
     
  9. Brad_Porter

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    Stooop it. Stop it now. :)
     
  10. Couch Potato

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    Dont worry about it, look at my learning curve on the HCPC forum!!

    Steve
     
  11. Dave N

    Dave N
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    er... but all this presumes that the listener has a "flat" hearing response - I dont know but I'd venture that this is unlikely. On the other hand perhaps it is insignificant compared to say the effects that the room (or indeed the speaker itself) has. Just a thought...
    D
     
  12. Couch Potato

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    The "Flat response" refered to earlier in the thread was Jase's in room response even allowing for fluctuations due to room resonances sub placements etc. The original thread was about trying to get as near as flat a response as possible and whether it was worth investing in a Behringer Feedback Destroyer to use as a Parametric Equaliser to "flatten" out the peaks associated with room resonation, poor sub-placement (maybe through necessity, have you seen the size of Servo 15, Velodyne 15" & 18" subs and SVS subs :eek: )

    I seriously doubt anything other than Whales or Elephants could hear the output of an HGS 18..... and it appears to be pretty much flat to 12Hz!!

    Steve
     
  13. Nobber22

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    Excellant! I'll take one along on my next whaling & hunting 'Last-minute.com' holiday in the Fall.
     
  14. Jase

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    You don´t hear it you feel it! As does anyone in a two mile vicinity.:D
     
  15. Couch Potato

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    I know, when I was measuring the output of my SVS my trousers were flapping but there was barely a noise (well from the sub at least, everything else in the room was rattling, in fact there were parts of the room rattling I didn't know I had!!)

    Steve
     
  16. Steve.EX

    Steve.EX
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    I can confirm that whilst obviously not "flat" my 2 servo's will play 15hz at approx 3db down from 20hz which may or may not be attributable to my (awful) 4mx4.5mx4m (W.L.H) room, still scary stuff at greater than 90db though!!!

    Steve.
     

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