BFD Users - Cool Software Set-up Tool

Discussion in 'Speakers & Subwoofers' started by Brian L, Apr 14, 2005.

  1. Brian L

    Brian L Cinematographer

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    Anyone check this out???

    http://homepage.ntlworld.com/john.mu...meq/index.html

    And there is an AVS thread talking about it here:

    http://www.avsforum.com/avs-vb/showt...hreadid=529224

    I have not actually tried to use it, but I did load it and fired it up, and am going through the documentation as we speak. If I am reading this right, this software, after taking room measurements, will actually identify the peaks, and then calculate the required BFD filters for you.

    Judging from the literature, it seems to be pretty easy to use, which hopefully will translate to a short learning curve.

    This looks to be way cool if it works as it appears it will.

    BGL
     
  2. MikeyWeitz

    MikeyWeitz Supporting Actor

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    Let us know how it works for you :)
     
  3. Kevin C Brown

    Kevin C Brown Producer

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    Looks interesting...

    I figure that any sub that has this stuff (Velodyne, and some others) has this kind of software built in. Kind of neat that someone would just offer up for public use. Brian, let us know what you think.

    I already use ETF5, and this looks to be a lot easier to use than that. [​IMG]
     
  4. Brian L

    Brian L Cinematographer

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    If all goes to plan, I am going to give it a run through tomorrow afternoon.

    It looks to be very user friendly, and has already found my soundcard without my having to do a deep dive into Windows. It has a built in tone generator that will do Sines, Pink Noise, Stepped Sines, etc.

    The user documentation is very well written, at least from the perspective of basic set-up procedures. Dare I say it, it almost looks idiot proof...'course, I will be able to test that theory tomorrow![​IMG]

    BGL
     
  5. BradJudy

    BradJudy Stunt Coordinator

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    I tried this tonight and here are my thoughts copied from the AV123 fourm:

    It seems to be pretty well done. It has a loopback function to eliminate the soundcard from the equation. It seems to be able to do a variety of tone generation and automated measurement. The default subwoofer 20-200Hz sweep went in 1Hz increments and took 10 minutes, but I think the interval can be tweaked to speed that up.

    The only problem after this sweep was that my big 20-40Hz hump (which measured as peaking at 20db above normal on both the RS SPL and ETF) measured as peaking 30db high. I'll have to do more measurements to see if this holds, but I'm done for this evening.

    (Techhead note - it is a Java app, so it requires you download and install the Sun Java JRE)

    Overall, this could be an excellent free alternative to TrueRTA or ETF for those just wanting to do frequency response measurements. For those with a BFD, it looks like it could be even more useful (not as nice as the R-DES software, but probably better than what you're using now ).
     
  6. PaulDA

    PaulDA Cinematographer

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    Does it require a special microphone for room measurements? If so, what kind?
     
  7. Brian L

    Brian L Cinematographer

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    Not at all, in fact they recommend the RS SPL meter, and have compensation built in for the fact that the meter will be run in C weighting.

    I would encourage anyone to go to the link and download the help files...very comprehensive, yet simply written. I didn't see anything that I thought would be difficult to understand.

    Oh, and the price is pretty damn good to.

    For those that did not check the link, this is software written been one of the lead tech guys at the now defunct TAG-Mclaren (well, the consumer audio part of TAG, anyway). He said he wrote this in his spare time, but it was based on software that was initially written for the TAG units.

    BGL
     
  8. MikeNg

    MikeNg Second Unit

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    BradJudy,

    Aside from the 30dB hump it reported, did you find that the measurements/recommendations were accurate/close to how you have your room calibrated? Of course, I'm presuming you have already calibrated your room before and you're just testing the app now.

    Mike
     
  9. PaulDA

    PaulDA Cinematographer

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    I don't suppose it'll run on my PowerMac notebook, will it? Otherwise, I'll have to borrow a PC laptop as my desktop is nowhere near the system.
     
  10. Chu Gai

    Chu Gai Lead Actor

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    Good question. It is a java applet. Ask the maker.
     
  11. BradJudy

    BradJudy Stunt Coordinator

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    Aside from the exaggerated hump, the measurements appear good. I'll do some more testing this weekend to see what setting works best for faster sweeps (a ten minute sweep is pretty absurd). I'll also have to see if I had the RS compensation turned on which would explain the discrepancy for the hump.

    BTW: Yes, I am doing this to test the app, and since I have a pretty reliable measuring setup, I thought I would do some validation for everyone. Posting follow-ups in multiple fourms is annoying though. I haven't even looked at the AVS thread yet and I'm already posting on this in three forums.
     
  12. Brian L

    Brian L Cinematographer

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    I was only able to give it about 90 minutes this afternoon. Too soon to say if I trust the data yet, but it was pretty easy to use. I did find that the onboard soundcard of my laptop lacked line level stereo inputs (mono Mic in only), thus off to Best Buy for a PCMCIA sound card.

    Once that was installed, things went pretty well.

    I do find the ability to program a start and stop frequency, as well as the spread (1/3 Oct, 1/6 Oct. 1Hz increments, etc.) very handy; press one button, and it plots the FR of the speaker in question pretty quickly.

    While I did not actually re-calibrate my sub as yet, I did run some 80 to 800 Hz 1/3 octave tests on my LCR speakers (I had an Audio Control Bijou for those). It made small work of dialing those in.

    One oddity which I would guess is related to the setup of my machine is that I am hearing some feedback from the Mic. I would have expected that the program would record the input from the meter w/o sending it back via the line-outs to the Receiver. Surely that's an issue with the soundcard set-up.

    Something else that perhaps relates to how I have the software set up is that it will not compute filters that boost any frequency; only cuts. I am fine with the notion that you can't boost a null, but not all valleys in the FR plot are nulls.

    Well, lots more to do, but unless the family hits the road for a day, I am not sure when I will be able to take a 2nd pass at it. Dang!

    But, so far so good....I was getting some use out of it in less than two hours....not bad at all!

    BGL
     
  13. Kevin C Brown

    Kevin C Brown Producer

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    Hey Brian- Does it differentiate at all between t=0 measurements with after the nodes have built up? Just curious... [​IMG]
     
  14. MikeNg

    MikeNg Second Unit

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    It could be the sound card. It may also be the volume you are running the sweeps at, and also the distance the mic is from the speakers.

    Mike
     
  15. Brian L

    Brian L Cinematographer

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    Kevin...NFI! When it first starts running a tone, there is a delay, and a message pops up indicating that its waiting for the bass to settle (or words to that effect).

    Mike...lots more experimentation for me to do, but I would not think distance would have any bearing on things. I would not expect the signal from the mic to get fed back to the outputs....there must be something in my setup I have wrong. Having said that, it is volume dependent.

    There are a couple other aspects of this program I do not fully understand, likely due to my lack or experience with programs of this type:

    Why do I need to run the left channel out to the left channel in? What does that do in terms of accuracy of measurement? I know you can plot what the program calls predicted results, which is said to be the FR of the signal at the output of the AVR (without influence of the room), but I am not sure I see what that buys me.

    Next, in the initial set up, they have you run through a test to make sure that the programs SPL meter matches the RS Meter. But they have you tweak the channel trim of the L, C, or R to do it. Later you set the master volume for the target SPL, and the program prompts you to record the volume knob setting that produces that result.

    Since overall SPL is dependent on Channel trim PLUS overall Master Volume, I am not sure why you have to do these two independent steps. I would think the initial setting of the target level to say 75 dB would be most easily accomplished with the Master Volume.

    Again, perhaps this is ignorance on my part, or something that derives from the fact that program was originally done for TAG gear.

    I am going to see what's going down over at AVS. I hesitate to ping the author with dumb questions just yet....

    BGL
     
  16. Kevin C Brown

    Kevin C Brown Producer

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    Left channel to left channel in: ETF5 does this too.

    What it does, is to then subtract the distortion from that signal from the measured signal from the RS meter. Effectively removes any anomilies of the soundcard itself from the room response.

    OK, so if it's waiting for the "bass to settle", then sounds like it's waiting for the nodes to build up. Be cool if it did both, but I think we agree (past thread [​IMG] ) that this is the more important measurement.
     
  17. Brian L

    Brian L Cinematographer

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    OK...loop back now makes sense.

    Thanks KCB!

    BGL
     
  18. Eric A

    Eric A Second Unit

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    Well I tried this out this weekend and it is a great tool. It is very accurate as well. I have used some different tools for measuring and this one is very good even using the Rat Shack meter. One thing I may mention is the program does a great job at not over EQing. By this I mean not cutting out large chunks of information. It will assign alot of filters if needed but most of them are small BW. Overall this allows a smooth curve over a broader seating area versus a one "Cash Seat". Of course you can work with it to get perfect response over the assigned curve and I did do a good bit of this. It provides instant feedback on what a given filter will do for you. I have seen the new Velodynes and Sunfires in action and to me this is a much better tool using a BFD. I know that AV123 is coming out with R-DES and SVS may have something but this is a great in between product and most that have a BFD will not ever need to go another route once using this program.
     
  19. Clinton McClure

    Clinton McClure Casual Enthusiast
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    I haven't had a chance to play around with it yet, but I loded it to my laptop Sunday. All I need now is a cable to connect my RS meter to the laptop. I'll probably work on it Saturday and see what I can do.
     
  20. John_Mulcahy

    John_Mulcahy Auditioning

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    V3.19 has now been uploaded to the website. The main addition this time is Midi comms for setting up BFD Pro filters, though you will also need a Midi interface. Details of the Midi comms are in a new help file accessible via the website (sorry, can't post links as a newbie on this board).

    There have been various other updates in the help text to add references to BFD Pro where appropriate.

    There is also a link to download a zip file of the jars used by the wizard so the app can be tried on Linux or Mac OS X platforms - I haven't tested on other platforms, however.

    Summary of V3.19 changes:
    • BFD Pro can now be set up over a Midi connection
    • Added a "Comms" menu, put COM port and Midi input and output port selection in there
    • Tweaks to helptext for unit.html, equaliser.html, soundcard.html, welcome.html (link to download site for J2SE V5.0 for Max OS X), avpcomms.html
    • Tweaks to the English help text for makingmeasurements.html, inputcal.html, filteradjustment.html
    • New helptext files added: comms.html, bfdcomms.html
    • "Generate Soundcard Debug File" added to the Soundcard menu to generate a text file with debug info following reports of problems with some multi-channel soundcards (RME 9632)
    • When the equaliser is BFD Pro the Aux tab is renamed to Sub2
    • Fixed a bug that caused wrong measurement values to be recorded when the SPL limiter was active

    Regards
     

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