6 Replies Latest reply: May 15, 2014 12:13 AM by birgit56
odettelepapillon Level 1 (0 points)

Recently purchased logic studio. Installed the 9.1.8 update and am running Mountain Lion.


For some reason, I am experiencing a "static" crackling sound when using the midi instruments, even when I am not recording. As far as I've noticed, it is not occuring during audio recording or playback. I recorded a quick track with the computer mic, and didn't notice anything, and I dragged a random audio file in to see if it would static as well, but no. A couple of times a warning popped up:


Sample Rate 40575 recognized.

Check conflict between Logic Pro and external device.


This happened first when I tried to record a midi track. Then it happened again when I tried to record an audio track with the midi track. I deleted all of the tracks and did the same thing again, and the warning did not appear those times.


Funning thing is, I don't have any external devices connected. I am still very much a beginner with Logic, but have done several projects with it in the past and have not experienced this problem. I'm not exactly sure what this warning means.


I also double checked to make sure there wasn't any outside interference, I disconnected my computer from my speakers and unplugged my sound system just to make sure my speakers weren't messed up, and it still crackled. I used iTunes to see if it was happening there, no static. I've gone through and made sure I don't have any excess programs running, just logic and preview, still static with midi. It will crackle even if I am NOT RECORDING and just goofing around. When I play the track, it will have the identical crackling experienced while playing.


A little frustrating, as I've been anxiously awaiting this purchase. Please, if you have any thoughts or suggestions, I will check them out.



Logic Studio, Mac OS X (10.7.5), 9.1.8 Logic update
  • odettelepapillon Level 1 (0 points)

    Screen Shot 2012-11-22 at 3.14.36 PM.png


    This is a screen shot of what happens when I first record a midi-file, so you can see the error message. As you can see, I have no external device connected, I'm even using the built-in midi "keyboard."




  • Pancenter Level 6 (9,440 points)

    Are you using your Mac's cheapo internal audio hardware?


    Logic is a professional application and is designed to use professional level hardware, it will run on the standard Mac audio but your sound and usability might be somewhat limited, however, it should work for what you're asking. Do you have a full set of surround audio hardware being used, speakers....etc?


    Since you're fairly new to Logic I presume you've checked out the manual, specifically:

    "Configuring You Audio Hardware" That chapter can be found at the link below... (Read This Chapter)


    http://help.apple.com/logicpro/mac/9.1.6/en/logicpro/usermanual/#chapter=2%26sec tion=0


    Set "Line-In" for the Input

    Set Built-In Audio for the Output


    Set the I/O Buffer to 256, if you hear a slight delay go down to 128.


    Do NOT record at a high sample rate because you can, it's of no use to you right now.

    Set the Sample Rate to 44.1 and the Bit-depth level to 16-bit.  Use Audio-MIDI Setup to do this, used to be located in the Utilities Folder.


    If you are running Airport or Wireless, try disabling


    If you do not have a surround setup, don't use surround sound.

  • odettelepapillon Level 1 (0 points)

    Thank you for the suggestions.


    I had previously tried all of the above but the airport/wireless thought. Unfortuneately, none of these things made a difference, including the wireless suggestion.


    Currently, I am using my Mac's "cheapo" internal audio hardware  (haha). I have a one year old 27-inch iMac,  a good pair of bose speakers, and a polk sub. I don't believe it is an issue with my setup, considering I completely disconnected and unplugged it.


    I did, however, do a little info hunting on the internal audio situation, since I was curious what is actually included, and I stumbled upon this interesting little tidbit about my model of iMac:





    Screen Shot 2012-11-26 at 12.44.18 AM.png


    I had previously wondered if I was hearing my mouse in my speakers as well (not just in logic). It appears that this model of iMac may have some grounding issues, as someone later in the thread suggested purchasing and using a ground loop isolator, which seemed to fix any extra interference for them.


    Ironically though, I have since opened logic, and do not seem to be encountering my previous static issue(yet).


    Fingers crossed, hoping that I will not be experiencing it again. Going to purchase a ground loop isolator, and continue to mess around with logic, just to make sure it was not just an internal audio issue with my iMac.

  • odettelepapillon Level 1 (0 points)

    Also, I found this helpful article on ground loops on apple support:



  • Pancenter Level 6 (9,440 points)



    I guess it could be a physical grounding problem, do you have any other peripherals connected to the Mac?

    You can always test out a ground problem using a "ground lift adapter" (inexpensive 3 to 2 prong wall adapter).

    Try an adapter on your speakers, if no change try it on the Mac, or any other device that's plugged into wall current and connected your Mac.


    The reason I said cheapo internal audio is both PC and Mac audio chips are purchased in bulk, mounted in the middle of noisy motherboards, have uneven frequency response and generally inferior sound.

    Having used Logic from long before Apple's purchase of the company that designed and programmed it, I never thought I'd see the day that Logic would be used with anything but exceptional hardware but that's all beside the point. Apple sells it and it should work with your setup.

  • birgit56 Level 1 (0 points)

    im experiencing the identical issue in logic x and have not been fortunate enough yet to have gotten any suggestions as to a fix... please inform us if you track down the source of the crackle...