Is the BFD worth it?

Discussion in 'Speakers & Subwoofers' started by Vaughan Odendaal, Jul 29, 2005.

  1. Vaughan Odendaal

    Vaughan Odendaal Second Unit

    Joined:
    Aug 4, 2003
    Messages:
    403
    Likes Received:
    0
    Trophy Points:
    0
    Hello people,

    I've heard many things about the BFD. How it can tame peaks, boost dips, and get a nice flat FR. But I've also heard that once you've used the BFD to get a flat FR, the punch in the bass that was there goes away.

    I would like to know from people who have the BFD (or similar equilizer) what kind of results they got in their room with their system. This is just a feedback thread. Do you like a flat FR over a slightly uneven one, has it brought about big advantages to you? Any disadvantages?

    Thoughts on this would be most appreciated. Thanks.

    --Sincerely,
     
  2. MichaelPR

    MichaelPR Second Unit

    Joined:
    Nov 16, 2003
    Messages:
    401
    Likes Received:
    0
    Trophy Points:
    0
    From my understanding....the best way to use it is to eliminate peaks....I don't think it can really boost dips that much...but I'm not sure....the reason you hear it might get rid of some of that punch you hear is because it can cut the fatty bloated overpowering bass from the movies....which in the end really helps the mid and highs shine...which in my opinion is just as important as the bass....this might be a good investment for you if you plot your FR now and it is all over the place....if you use the excel template that is here somewhere and post your results someone can probably point you in the right direction.
     
  3. Vaughan Odendaal

    Vaughan Odendaal Second Unit

    Joined:
    Aug 4, 2003
    Messages:
    403
    Likes Received:
    0
    Trophy Points:
    0
    Thanks, Michael. Unfortunately, the SPL meter I had has been sold in our shop, so I'm going to have to buy one. Although I don't know what is more important, buying the SPL meter, or Avia.

    In any case, I think my room does suck, big time. I mean, for music, the bass with my PB-10 can sound slow and boomy at times. This is with the subwoofer calibrated at 3db's less than the other speakers. I would like to find out how bad my room FR is, but I have no way of doing that until I get myself a SPL meter.

    --Sincerely,
     
  4. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    1
    Trophy Points:
    0
    Unless you flatten the FR, you have no clue how your sub sounds and you have no idea if you're "calibrated" or not. If you miss the artificial "punch" that you might hear from a passing car, you can always add it back.

    Basically, you can't pass any informed judgement whatsover without knowing what your room is doing.
     
  5. Vaughan Odendaal

    Vaughan Odendaal Second Unit

    Joined:
    Aug 4, 2003
    Messages:
    403
    Likes Received:
    0
    Trophy Points:
    0
    As I said, this is just a feedback thread. I just wanted to know from people who have used the BFD (or similar kind of devices) what kind of benefits they got.

    I don't understand this comment you made:


    About the calibrated comment. What does flattening the FR have to do with not knowing if you are calibrated or not?

    --Sincerely,
     
  6. MikeyWeitz

    MikeyWeitz Supporting Actor

    Joined:
    Feb 10, 2002
    Messages:
    939
    Likes Received:
    0
    Trophy Points:
    0
    To address your last question. When calibrating an non Eq'd sub, you are calibrating it to the Fr w/ the highest peak. If you have a 4-5db peak @ 60hz, then that is what you are calibrating it too. You will hear that big peak, but the lower fr will obviosuly not have as high an output. Getting it flat as possible allows you to REALLY calibrate it properly to most if not all the fequencies since they are @ roughly the same db level.

    Some people say they loose the punch because the punch was their peak.

    The flip side is you can run your sub @ a higher level becasue it is more even.

    As far as null's, you can't really adjust them by boosting that fr by more then 3-5db or so on the BFD and will be very lucky if it boosts that output by that much. A null is more of a room interaction factor then anything else and the best cure for that is to move the sub.

    That being said, the BFD is certainly worth it.
    SPL meter and AVia are both important because you need both to calibrate (well, you CAN do it without Avia, but is real good to have anyway).

    I am looking forward to eq'ing my SVS 16-46PC+ when I get it this weekend.


    I may go the eq wizard program route, get a midi adapter and do it automatically. I hear it only takes 5-1mn that way instead of the 3-4 hrs it tokk me my 1st time with my 10" Dayton.

    nOT SURE WHEN i WIL FIND THE TIME TO EQ IT (probably not this weekend), but it is something that needs to be done for sure!
     
  7. Vaughan Odendaal

    Vaughan Odendaal Second Unit

    Joined:
    Aug 4, 2003
    Messages:
    403
    Likes Received:
    0
    Trophy Points:
    0
    Thanks Mickey! Good info.

    --Sincerely,
     
  8. MikeyWeitz

    MikeyWeitz Supporting Actor

    Joined:
    Feb 10, 2002
    Messages:
    939
    Likes Received:
    0
    Trophy Points:
    0
    WHy do people always call me Mickey?
     
  9. Edward J M

    Edward J M Cinematographer

    Joined:
    Sep 22, 2002
    Messages:
    2,031
    Likes Received:
    0
    Trophy Points:
    0
    The best of subwoofers can sound boomy and plodding in a poorly conditioned room. Slow bass usually results from excessive reverberation in the room. Think about how a 1200 ms RT30 time at 50 Hz would effect the SQ of the bass on music.....not pretty.

    While reducing a peak with a PEQ will also reduce reverberation times at that frequency, it really doesn't address the underlying problem, which is poor acoustic conditioning.

    While a PEQ is a useful tool, room treatments and bass traps are the true foundation on which to build great bass. Not only can they trap excessive reverberant energy, they can also significantly reduce the magnitude of peaks and nulls in the room, and smooth out the FR at several listening positions.

    This will help eliminate the need for extreme cuts with the PEQ, which might help at one listening location, but will likely hurt the response at others.
     
  10. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    1
    Trophy Points:
    0

    You most likely have a large hump in FR, and the SPL meter will read the SPL of that hump amidst the pink noise and you'll adjust level to that. All else will be too low. Proper calibration involoves a flat FR.

    As Ed says, though, all the EQ bands in the world don't replace proper acoustic conditioning and placement.
     
  11. Victor Ferguson

    Victor Ferguson Stunt Coordinator

    Joined:
    May 2, 2005
    Messages:
    120
    Likes Received:
    0
    Trophy Points:
    0
    I think its one of the best upgrades a person can do to there setup. It's only 100 dollars retail and I can't think of a better way to spend 100 dollars for the improvement it can provide.
     
  12. MichaelPR

    MichaelPR Second Unit

    Joined:
    Nov 16, 2003
    Messages:
    401
    Likes Received:
    0
    Trophy Points:
    0
    I also don't know what kind of display you are using but AVIA will make it look ten times better....Before you get a BFD I would spend the money to get Avia and an spl meter....Avia will also have some sweeps and you can get an idea as to what is happening with your FR and it will also help you put the sub in phase.....
     
  13. Wayne A. Pflughaupt

    Moderator

    Joined:
    Aug 5, 1999
    Messages:
    6,208
    Likes Received:
    57
    Trophy Points:
    9,110
    Location:
    Katy, TX
    Real Name:
    Wayne
    Vaughan,
    As others have noted, it might seem that way once the peaks are eliminated. The other reason is that it’s generally a mistake to EQ a sub for flat response. Most people think it sounds weak and unsubstantial that way. If you end up feeling the same once you flatten out your sub, then you’ll will probably want to dial in a house curve. Here are some old posts of mine on the subject you might want to study:
    http://www.hometheaterforum.com/htfo...014#post530014
    http://www.hometheaterforum.com/htfo...918#post499918
    http://www.hometheaterforum.com/htfo...014#post530014

    Contrary to what’s been stated, a parametric EQ can deal with most low points in response, as you can see from this graph from Sonnie Parker’s BFD Comprehensive Set-Up Guide.



    [​IMG]



    What the EQ can’t deal with is nulls. Nulls are often mistaken for any and all low response points, but the truth is, not all of those are nulls – as Sonnie’s picture shows. You can recognize a true null because it won’t respond to boost. So it’s best not to “burn” the headroom trying.

    As Jack and Ed noted, the EQ doesn’t really fix response problems, it only “deals” with them. If you have a dedicated theater room you might look into bass traps. However, most of us setting our systems up in living and family rooms don’t really have that option. If that’s your situation, the BFD will work wonders for your sub’s response. And it’s a fraction of the cost of bass traps.

    Regards,
    Wayne A. Pflughaupt
     
  14. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    25
    Trophy Points:
    0
    Location:
    NorCal
    Real Name:
    John
    I've heard what a BFD did for a PB-12. Pretty impressive actually. It sounded OK without the BFD, but when this guy turned it on, it sounded a lot cleaner and solid with the peaks tamed. It really is going to depend on what your FR looks like before you should decide to get one.
     
  15. Vaughan Odendaal

    Vaughan Odendaal Second Unit

    Joined:
    Aug 4, 2003
    Messages:
    403
    Likes Received:
    0
    Trophy Points:
    0
    Thank you guys! Excellent responses all round. Ed, Jack, thank you for clearing up my questions. Mikey, sorry about that, I don't know, your name has a kind of Mickey ring to it.[​IMG]

    Wayne, I really appreciate you helping me with the links. Thanks. Very good information, and I haven't finished reading it either. This is my situation. I have a 3400 cubic foot room, untreated, just like your typical room.

    Bass traps, as much as I would like to use them, are impractical in my case. Acoustic paneling is also out of the question. As Ed says, a BFD will help with the reverberation times. So if I'm understanding things, the major use for the BFD is to remove the excessive boomy peaks in your subwoofer's response?

    Nulls you can't boost, as it's like a black hole? Is that right? Michael, I was thinking about getting Avia. My tv is the Sony 72cm DRC (4:3). Yeah, yeah, it's square.[​IMG] It's a heck of a nice tv, and it's quite old now.

    I don't know if Avia will help me with the picture quality, since I'm PAL. Guys, thanks again for the detailed responses.

    --Sincerely,
     
  16. Edward J M

    Edward J M Cinematographer

    Joined:
    Sep 22, 2002
    Messages:
    2,031
    Likes Received:
    0
    Trophy Points:
    0

    Be careful not to take my statement out of context. A PEQ reduces the amplitude of the modal excitation frequency. This in turn will reduce the amplitude of the mode itself which will inherently lessen ring time. But a PEQ obviously cannot actually trap and eliminate reverberant energy in the room the way acoustic treatments and bass traps will.

    A PEQ no doubt can improve the SQ of the bass, but room treatments and bass traps will have even a more significant effect on the SQ, and this cannot be seen by plotting the FR alone. You will also need the capability to look at the room's decay signature over time.

    Definitely get the PEQ, and definitely learn to plot the FR and flatten peaks and raise lows (to the extent they are not true nulls). But don't stop there - when you move out and dedicate a room to hi-fi and HT, there is a whole other dimension of improved SQ awaiting you from proper acoustic conditioning. You will never realize the full potential of your system (not even close) without taking this next step.
     

Share This Page