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BFD & Room EQ Wizard

Discussion in 'Subwoofers' started by stevefish69, Oct 7, 2005.

  1. stevefish69

    stevefish69
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    Thanks to the missus i've now got a nice BFD between the Amp and Sub.

    I've also downloaded "Room EQ Wizard" and bought the leads from soundcard to SPL meter. I'm gonna spend a couple of hours tomorrow having a play.

    Question is do you guys using EQ wizard connect to the BFD via a midi interface, or do you input the BFD settings manually. Does EQ wizard work out what cuts are needed where, or is this a job for eye's on the chart?

    I'd like to try EQ 1st before resorting back to my manual tones, and piece of paper. Mainly because i've heard that it is so quick and easy once set up.

    Thanks

    Steve
     
  2. Mr Incredible

    Mr Incredible
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    Room EQ will calculate the BFD points for you. If you are fortunate enough to have a PC with MIDI it will set the BFD for you as well.

    Set Room Wizard "Equaliser" menu to BFD PRO, and then youwil get the 12 set points on the BFD. Run your sweep, then find your peaks and then let it calculate. You can manually adjust the settings in the Wizard to see the effect on the curve.

    So far I have manully set the BFD. Once you get used to the double ENter to confirm a change you'll soon be having the BFD singing along. (so to speak!)
     
  3. stevefish69

    stevefish69
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    Cheers,

    I'm sure it's easier to actally enter the figures into the BFD than it looks on the SnapBug site.

    I'll post graphs tomoz and let you know how i got on.

    On another quick note, i'm using a 5m MosterBass 400 sub cable from BFD to Sub, and am temporarily using an 1m Ixos Digital 75 Ohm interconnect between Amp and BFD.

    Would the Ixos suffice as a Sub Cable :confused: , as it seems to have a decent center core coupled with good shielding.

    If not, then i may look at trading both cables for a 1m & 2m length of the same type of Sub cable. I'm using Maplin jack plug converters to enter the BFD.

    Steve
     
  4. Mr Incredible

    Mr Incredible
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    I made my own sub interconnect following some instructions in the Interconnect Forum. 15m cost me about £12 in total. :) It sounds fine to me, but hten again I do not have anything to compare it to.

    Yeah, the BFD, once you get used to it, is easy to do manually.
     
  5. bob1

    bob1
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    Steve that cable will be fine ,i use a 75ohm cable on mine which i also made myself, i also used the same cable to connect dvd to amp.
     
  6. Mr Incredible

    Mr Incredible
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    Steve, not that you would give up trying to set up your BFD with the ROOM EQ Wizard, all I can say is that after many days, yes days, trying to balance all my speakers and sub in terms of total frequency response, my end result was excellent.

    My "trouble" was that using a laptop's Mic input on the Room EQ Wizard is a :nono: In the end had to resort to dragging my desktop into the lounge from my study and using the soundcard on that. Once I had done this, used the Line In, ensured the SPL was attached to the RIGHT input on the Line-In, and I had the LEft Out looped to the LEFT IN (using 3.5mm to female RCA with Phono patch leads), the only other thing I found which was trial and error was that the SPL needed to be on the 80db range. I used the AVIA disc to calibrate at 85db. I found if I used the Denon internal tone @ 75db, the Room EQ had a few problems setting the levels to calibrate.

    After that I used a 20 - 150 Hz Log sweep with a target of -6db. All went very smoothly. Because the sweep is quick, it allowed me to move the speakers and sub around and retest to check the best combination. Of course the sub position is somewhat limited due to furniture, but I tried about 6 positions and I now have it in the best I could find.

    I got the best FR I could on the sub, measured on its own, then I adjusted with the TOTAL FR in mind. I didn't flatten the sub, I flattened the entire set up for 20 - 150 Hz (80Hz xover).

    The end result is light night and day. Playing back anythig with and without the BFD in line (i.e. +/- bypass mode) the sub sounded clearer, focussed and in control. In fact it made my whole soundstage better as I run the fronts large (I had a flat FR on my fronts below 30Hz :D ). Everything just came together.

    Well worth the time, money and effort in setting up the Room EQ.

    I'll be interetsed to hear of your experiences and results.

    Bob
     
  7. stevefish69

    stevefish69
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    Gave it a good shot with EQ Wizard but failed to get it to plot the measured chart. All i got was a straight grey line, so gave up after a while.

    Just spent the last 2 hrs manually setting the BFD using the old charts. I've attached them for comments and have hopefully done it right. I lowered everything to try and bring the 63hz dip in line. Will give it a go at that for the moment, and only used negative gains.

    I then Re-Calibrated the sub levels up a notch to make up for it. She's still only sitting with the Amp gain at -5db, and the Sub gain at 12 o'clock while running 3db hot.

    Forgot to mention Cross Over at 80Hz, and all speakers set to Small. Will have a play with Large and different Crossovers when i get more time.

    Steve
     

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  8. bob1

    bob1
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    Looking good to me steve ,how do you find the sound now?
    When you say "Amp gain at -5db" do you mean the sub out ,that seems a little low for the bfd unless you have the volume at high levels all the time, did you follow the instructions for setting the levels on the snapbug site.My sub out is at +8.5db(not that all amps are the same) ,using too low a level will cause the bfd not to function correctly.
     
  9. stevefish69

    stevefish69
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    I've not had a proper viweing yet, but 1st impressions are that a hell of a lot of BOOM has gone. I suppose it'll be a similar experience to getting the SVS. You wonder where all the Bass has gone, and then it hits you like a ton of bricks when the director intended.

    Do you guys all run flat, or are you running house curves to liven things up a little?

    i set the BFD input level by playing FOTP at my maximum viewing level (-10db on main volume) and just had the red LED flashing as instructed.

    Would it be worth knocking the Sub out from -5db to a little higher and adjust on the back of the Sub instead, and turn it down when showing off ect. I normally listen between -20 and -15db

    Steve
     
  10. Mr Incredible

    Mr Incredible
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    My "house curve" is nothing more than a curve which gives the flattest FR on my mains running large. With my amp at -4db and sub at 11:00 o'clock, most listening harldy ever got an amber led to light up let alone red. So I've just turned up the wick a tad on the amp and dropped the sub a little. Now I'm running the amp at +4db and the sub is just before the 10 o'clock mark. THe BFD seems a little livelier, which with someone's observation it apparently needs to be to work optimally. I presume it must be the S/N ratio improves with a higher input level.

    I had the same result with the boominess gone. WHich you would expect with having a 26-28Hz room boost of about 15db withut adjustments..
     
  11. AngelEyes

    AngelEyes
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    I found that position makes an incredible difference so output levels will depend on your room.

    In an alcove I ran the sub out on the receiver at +4db and 11 oclock. Now I have it in a corner I run it at -5db and 9 oclock and it still sounds a little hot to me. I guess if you really find a sweet spot for your sub it really increases the output!

    I haven't setup the BFD in my latest 'corner' position but I have attached a graph showing 3 different positions in the same room. The Yellow is where I am keeping it. A little bumpy but I am sure the PEQ will sort the worst of that out.

    You can see the original output from the sub in the alcove here . Note this is where i had the receiver output and sub gain much higher. The output difference is huge!
     

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  12. stevefish69

    stevefish69
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    Do you guys use the SPL correction values to plot your charts. I did to plot mine and feel that i may have wasted some time setting up the BFD to them :suicide:

    Do you think it would be worth setting up another Preset using Raw data only so that it will be easy to do a comparison.
    Unfortunately i still have not been able to have a proper viewing to see the full benefits of the BFD.
     
  13. JIT

    JIT
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    Anyone got a www address for the Room EQ Wizard where i could download it?
     
  14. SimonO

    SimonO
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  15. JIT

    JIT
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    Thanks.
     
  16. Mr Incredible

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    I used a correction file and thought it worked fine. The lower frequencies were increased by the offset figures I loaded in.

    I've attached the file I used. On a first attempt I found that the figures I had were of the incorrect sign. I had to make the readings "negative" for the right correction to happen.

    Also if you have the meter on C weighting, you do not need to have the Wizard compensate for C weighting. (Click on the Meter menu item).

    HTH
     

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  17. SimonO

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