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Limp jig issues...

joeybuttsjoeybutts
in DIY
Finally got around to making my limp jig and start measuring.....and of course issues.  

Following Hong's thread on PETT and I'm not getting what he is showing.  I get V-Fib and that's it.  No smooth-two-graph response.  I have sound from the speaker, appears to be wired correctly..... but just a crazy squiggle that appears to represent Phase (it seems to be centered around zero for phase)

I've clicked M+P, PN Pink, calibrated with jig connected but speaker not........  

What am I missing?

Comments

  • joeybuttsjoeybutts

  • joeybuttsjoeybutts

  • jr@macjr@mac
    Looks like a drive level issue somewhere in the chain. 
    I have a signature.
  • dcibeldcibel
    Yeah that's just some noisy mess for sure. Is that wire on the speaker side of the resistor making good contact?
    I'm not deaf, I'm just not listening.
  • joeybuttsjoeybutts
    JR, Not sure what to do to fix that.

    D, yessir.  I'm quite heavy handed, definitely good contact.  soldering I make sure both physical parts are touching.  maybe issue in my RCA/ 1/8" jacks?
  • joeybuttsjoeybutts
    So I turned down the volume to almost nill and it's starting to look like what I would expect, but, it's almost muted......
  • joeybuttsjoeybutts
    I'm guessing this looks better?
    Also, when I calibrate, the gauges are red, no matter what.  Not sure what's happening there....


  • dcibeldcibel
    edited July 2020
    joeybutts said:
    Also, when I calibrate, the gauges are red, no matter what.  Not sure what's happening there....


    Your signal is being clipped, turn down the volume under the "generator and input monitor setup", multisine level is the one to adjust for pink noise, and you have to hit the start/stop button on that window for the settings to take.

    joeybutts
    I'm not deaf, I'm just not listening.
  • joeybuttsjoeybutts
    1.  I can't get a clean graph no matter what.

    2.  Parameters keep coming out crazy.
  • dcibeldcibel
    edited July 2020
    Let me guess, the soundcard you're using is the built-in junk on your laptop? You might try poking around the windows settings, sometimes you have to specify that you want the input to be a low sensitivity line-in, not a high sensitivity for a microphone. I would also verify that the sampling rate for playback and recording device in windows matches the sampling rate set in Limp.


    joeybutts
    I'm not deaf, I'm just not listening.
  • joeybuttsjoeybutts
    Fffffffff.  Ok.  Will try.
  • joeybuttsjoeybutts
    I've gone through a bunch of control panel/sound menus, gone to 2ch/48000/24.....volume can be higher, best graph so far....
  • joeybuttsjoeybutts

  • joeybuttsjoeybutts
    I've been fiddling, can't seem to get the right figures....VAS of 49L........ one off basically ND105 with ferrite magnet.......
  • dcibeldcibel
    The sweep still looks like crap, noisy and just a mess below 40Hz, don't bother trying to get parameters until you can work out a clean measurement. Maybe a loose or dirty connection, but more likely the built in sound on your laptop isn't up to the task. Try another computer, with a real soundcard, or an external sound interface. FWIW I use a Steinberg UR22mkii for my measurement rig, it works well and is portable. My jig is similar to yours, just with a couple extra resistors so I can measure with a power amp connected, and a switch for using a mic for SPL measurements. You'll find a pretty good description of this jig in this ARTA application note:
    I'm not deaf, I'm just not listening.
  • rjj45rjj45
    Making progress, Joey. Once you get your setup right it should be stable every time. For now, adjust your Zohms scale on the left so the max is something like 60-100 ohms. That should "pop up" that last measurement to something more normal.
    BTW, I used to always run LIMP with a swept sine, but a couple of folks recommended pink noise. Either will work, but pink noise is much faster.
    But Chahly - Stahkist don't want speakers that look good, Stahkist wants speakers that sound good!
  • joeybuttsjoeybutts
    Can you guys recommend something.solid.that will work?  Getting frustrated with so many things not working......
  • KornbreadKornbread
    Do not use a behringer uca202. 
    dcibel
  • dcibeldcibel
    You can use a Behringer UMC202HD though :)

    The audio interfaces are great to have if/when you want to upgrade to the full ARTA jig. You'll already have the phantom power for the mic and clipping indicators.

    I'm not deaf, I'm just not listening.
  • jr@macjr@mac
    My UMC202HD was pretty noisy. Switched to the Creative X-Fi. 
    I have a signature.
  • joeybuttsjoeybutts
    Like this

  • joeybuttsjoeybutts
    What's the most reliable but budget soundcard you guys would recommend?  I'm ready to start moving along with designing, or can I just use my mic and skip the limp jig?
  • 6thplanet6thplanet
    My buddy does a little limp jig right before he gets up. 😝
    joeybutts
  • jr@macjr@mac
    https://www.ebay.com/itm/154005206298
    I use this one. Should go for about $40.


    joeybutts
    I have a signature.
  • joeybuttsjoeybutts
    Great news.  Will pick one up
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