EFT users (low freq sub eq...)

Discussion in 'Archived Threads 2001-2004' started by Kevin C Brown, Jan 28, 2003.

  1. Kevin C Brown

    Kevin C Brown Producer

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    Me so happy. [​IMG]

    I wish I could remember who the HTF-er was who got me motivated to try this software. (Had it downloaded on my PC for like 4 months before I could get all the cables and connectors together, and the time to try it.)

    1) I don't get that great performance out of my soundcard. You know where they say to switch from 44.1 kHz to 48 Khz to clean up some of the plots? Well, my 44.1 kHz looks a lot worse than the example in the software, and when I switch to 48 kHz, it looks like the 44.1 kHz example in the help sections... But it looks like most of the "garbage" is way high up in the freq response range, > 1000 or 10k Hz.

    2) I can now do a test in 5 sec, that once took me 20 min with a discrete test tone disc and and Excel spreadsheet. Did I say I was happy? [​IMG] Very powerful.

    3) I was super surprised, that the initial plots I'm getting with EFT look *very* close to the hand/manual plots I did over a year ago, the long way. Peaks and valleys in all the right places. So even though some people made fun of the "brute force" method I had used in the past, except for how long it took, it did still give me the right answers. Just that now, a heck of a lot easier to do averaging between the 3 best sweet spots in the room, rather than just where I sit... [​IMG]
     
  2. BruceD

    BruceD Screenwriter

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    Kevin,

    I've been using the sw for the last 3 years (since version 4.0) with outstanding results.

    Do you take avantage of the pseudo-real-time analysis?

    Are you using the RS SPL meter as the mic/preamp or did you get a calibrated mic and mic-preamp?

    I think the sw is also invaluable in locating 1st reflection point problem areas (like a coffee table) with it's impulse response graphs.

    I agree this sw is the best thing since sliced-bread for acoustically balancing a room/speaker SYSTEM.
     
  3. Kevin C Brown

    Kevin C Brown Producer

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    Bruce! [​IMG]

    "Pseudo real time analysis": that's just using the short (1s) measurement time, right?

    Yes, RS meter so far. Oooh: does the ETF software include the "calibration" for the RS meter? (Probably not, right? Anyway to do this? I know there's a way to input a cal file for a mic, but I haven't gotten that far yet...)

    I theoretically understand what an impulse graph is, but I need to understand more its practical use in an HT...
     
  4. BruceD

    BruceD Screenwriter

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    Yes, I thought the RS calibration file (something like RSCAL.cal) was included with the software.

    I've been using my own calibration file (for my calibrated mic) for the last 2 years, so I probably threw the RS file away.

    The pseudo real time measurement is talked about in the MSWord file manual in the "Additional Features of ETF5.x" section (from my April 2000 manual):
     
  5. Jeff Kohn

    Jeff Kohn Supporting Actor

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    I agree, ETF is a lifesaver. I can't believe people actually used to manually take measurements and plug them into an excel worksheet. [​IMG] ETF is soooo much easier.

    Hey, does anybody happen to have the URL to the online guide that somebody wrote to using the BFD/ETF combo? I saved a copy to my hard drive for reference, but the topic has come up in another thread elsewhere and I wanted to post a link to the online version.

    Edit - nevermind, found it here: http://www27.brinkster.com/jmag999/
     
  6. Kevin C Brown

    Kevin C Brown Producer

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    Jeff- You're awesome dude. Has a link for the RS cal file right there! [​IMG]

    Hey, stupid question, I thought I saw somewhere that for the low freq measurement, that it goes from 20 to 240 Hz. But even on the very 1st graph from your link, (and when I ran the software too), looks like it peters out just above 128 Hz.

    ??


     
  7. Jeff Kohn

    Jeff Kohn Supporting Actor

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  8. Kevin C Brown

    Kevin C Brown Producer

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    Jeff- I will have to take another look, but I did set the coord axis to 20 to 200 Hz, but I only got the graphed line out to just past 128 Hz.

    Do you know if there's anyway to get ETF to save a data file of the measurements? (Maybe I need to buy the software for that... [​IMG] )
     
  9. BruceD

    BruceD Screenwriter

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  10. Kevin C Brown

    Kevin C Brown Producer

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    Drats! [​IMG] Man, I wish they had like a $50 or $75 version, just because I'm not going to touch most of what the program can do.
     
  11. Kevin C Brown

    Kevin C Brown Producer

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    Hey all! [​IMG]

    Playing around with it again. I figured out my #1 problem in the 1st post. Checked my sound card settings, and it was set at "good" sample rate conversions for both playback and recording. ("Good" says a good data rate conversion, but fast.) When I changed both to "best" (best = best data rate conversion, but slower performance), I got the identical graphs in the ETF help file. Awesome...

    I also found out another answer: for the low freq test of ETF, it only tests to 150 Hz. To get higher, for example, 20 to 200 Hz, just use the full range test and set the coords for the freq range of interest. But do get better measurements with the low freq test.

    Weird: I just spent another couple hrs playing with the BFD, and I found that sub alone, I can get a lot of improvement with 3 filters, but when I combine it with the mains, and with the phase differences induced, it is actually worse than with no filters. But if I go back to just 1 strategically placed filter, I can still get a fair amount of improvement for the mains+sub graph. Simple is better in my case at least... [​IMG]

    I also tried used an analog eq on the low freq portion of my mains, but try as I might, I couldn't really get any improvement over not using that eq at all.

    Interesting!
     

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