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ASW750 BFD'ing

Discussion in 'Subwoofers' started by Stellavision, Sep 7, 2004.

  1. Stellavision

    Stellavision
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    I have finally purchased a Behringer feedback destroyer and I am going to attempt to equalize my B&W ASW750.
    I have done a chart of my pre-bfd tests and wouldn't mind some input on possible best ways of flattening out my response. I don't fully understand how to work the thing yet! :blush: I'm reading away at the snapbug site.
    I will upload the new chart for comparison post bfd'ing.
     

    Attached Files:

  2. Stellavision

    Stellavision
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    Sorry, didn't realize it would upload that small. I will upload one to a different host soon to avaoid the forums upload limitation.
     
  3. recruit

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    HI Stellavision,

    Are you disconnecting your speakers or trying to equalize with them connected?

    John :)
     
  4. Stellavision

    Stellavision
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    ah, at last I can access the forums!
    Hi John,
    The results above were with my speakers connected, but I have tested again with my remainding speakers disabled.
    I am posting I better image of my pre bfd response. I have used DIRECT mode on my Pioneer 2011 and crossover set at 80 hz.
    I hope this evening to start the smoothing proccess.
    [​IMG]
     
  5. Stellavision

    Stellavision
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    Where is the best place to start?
    Do I bring everything up to the 16hz mark or try and level at around the 40 hz dip?
    Obviously the chart is undulating somewhat, so I am a little unsure in where to start.
     
  6. recruit

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    Hi Barrie,
    I found that i had a better sound when my speakers were connected,although on the snap site it does say that to test without speakers. It seemed that i could get a smoother response acorss the 16hz to 143hz and intergrate the sub better.
    When choosing frequencies to adjust pick out the main troublesome peaks and troughs but remember that when you adjust 1 frequency it can have an adverse effect on others and that is why you need to use the Q setting on the BFD or else known as the Bandwidth button, once you start altering a few you will start to see the effect that is has and get a better understanding of the Bandwidth adjustment.
    I have tried so many setting's, but i found that haveing an House Curve gave me the best sound this was starting at 16hz with an SPL of 87db and slowly dropping across the frequencies to 143hz to 82db this then gave it a drop of 5db across the band, also this setting was with volume on my amp set so that i read about 85-87db on my SPL meter at the 16hz starting point, i think it does recommend this initial setting in BFD Snap guide.
    It is really a case of trial and error but once you have it correctly set just store it in the presets, and this can also be done for 1 Films & 2 Music.
    Oh yes My crossover was again at the 80hz setting found this to be the best crossover point.

    Hope you enjoy it mate let us know how u get on :smashin:

    John :)
     
  7. Stellavision

    Stellavision
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    Right, first of all, my tests above were pointless as I forgot to press bypass and filters were in use. I re-tested in bypass mode, but this time I tested using PLII on my amp seeing as most of my use is multi-channel. The peaks and troughs are exactly the same as in stereo direct mode as it happens.
    I have also done some testing this evening and as you can see, my first major hurdle was the huge peak at 45 hz.
    I have spent a good 2 or 3 hours trying to master the bfd and have got my self a much smoother response with a very steady descent from about 31.5 until it steeply drops off at 89.
    Have a look at my chart and see what you think and I welcome any suggestions on what improvements I could make. I'm sure I will have a few more tweaks before I'm 100% happy, but I'm quite pleased so far.
    [​IMG]
    Blue is before and pink is after.
     
  8. recruit

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    Hi Barrie,

    That looks really good ;) do you find that the bass has tightened up alot more and how does it sound to you?

    John :)
     
  9. Stellavision

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    Hi John

    I am very happy with the sound so far. I have not had chance to try much, but I have been listening to some of the music channels on Sky tonight, MTV, etc..(connected via optical from Sky+ box) and the bass is a lot tighter, better defined and generally 'nicer', and of course there are no sudden increases in volume when the bass line hits that big 45 hz hot spot.
    I was going to try and level off a bit more between 22 hz and 31.5 but I think that the small boost low down at around 25 hz is not such a bad thing.
    :thumbsup:
     
  10. rags

    rags
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    Been lazy and still havent ordered it yet.

    Must remember tomorrow - order BFD !
     
  11. recruit

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    Hi Barrie,

    I think your'e right, generally there is'nt too much information on discs in that region so therefore for the sake of more equalisation better off keeping it to a minimun ;)

    John :)
     
  12. Stellavision

    Stellavision
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    Rags, it is well worth it. ;)
    By the way, I won't be able to make it to yours on Saturday as I have to take my daughter to a party, but thank you for the invite.

    John, I think I will leave it as it is. :)
     
  13. rags

    rags
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    Barrie,

    I cant do this weekend anyway. The C2 isnt back yet - they have promised it to me for this Tuesday. Im going to try and set something up for next week.
     
  14. Kazman

    Kazman
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    Next week is better for me anyway.This saturday is my cousins engagment party.
     
  15. Stellavision

    Stellavision
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    I'm going to Malta next week, so I'll probably miss your next demo session as well.
    It's probably for the best, as I'll only get really tempted to upgrade and as I said previously, it's not very practical at the minute!
     
  16. recruit

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    Hi Rags,

    I am getting the dem of the M&K mx350 today so probably better if next weekend aswell,

    John :)
     
  17. rags

    rags
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    John - let us know how you get on with the M&K.

    Right my BFD arrived yesterday and I have a few noob questions -

    1. I am going to use a couple of interconnects I have as temporary sub leads. Does anyone know where I can get 1/4 inch jack converters from ?

    2. I have been looking at the snapbug site re sinewave downloads - thers seems to be lots of them. Before I start downloading and cutting onto CD how can you tell what frequency each one is ?

    3. I am using Matts Meridina pre pro to do this. Is it worth me waiting till I get my C2 back ?


    Thanks
     
  18. recruit

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    Rags,

    You need atleast 2 1/4" jacks and if you have a maplins nearby they will do them.
    Also when you download the sinewave's they will be named SIN16hz - SIN163hz
    Reference to the meridian it will have different characteristics to the Parasound so probably you will need to reconfigure once you get the C2 back.

    John :)
     
  19. rags

    rags
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    Thanks John

    Do you mean reconfigure the filters when I get my C2 back or simply recalibate the level ? Both ?
     
  20. recruit

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    Hi Rags

    I would say both ;)

    John :)
     
  21. rags

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    Ok mate - may not be worth it then but Ill plot my frequency response in the meantime.

    I found the phono to 1/4 jack converters at Maplins - 99p each. Thanks
     

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