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Strange chirping sounds when recording

Discussion in 'Recording' started by Todd, Jan 12, 2015.

  1. Todd

    Todd Guest

    Hi all,

    Okay, so here’s a long tricky question that I’m seriously hoping someone can help me with!

    A high pitched chirp/click/zapping sound has been appearing through my computer recording setups lately.

    Here’s where it gets tricky.

    I first noticed it when recording a flute part through two different dynamic mics running into a VoiceLive Touch, a Kaoss Pad and into my laptop’s soundcard. The original recording was done in Audacity, but I noticed it showing up in AudioMulch as well. At first I chalked it up to some digital artifact from the VLT or the KP3. Incidentally, it didn’t seem to matter which audio driver I was using, one of the Windows drivers or ASIO.

    Taking the VLT and KP3 of those out of the system, however, did not help. I tried different mics, different cords, no difference.

    I started running the mics through my ART Gold preamp and then directly into the computer’s soundcard… still there.

    I bought two new condenser mics. Still does it.

    Thought it might be the optical mouse; still does it without it being plugged in.

    I considered that it might be a ground loop issue, but it still does it whether my computer is plugged in or running on its battery.

    Even so, I ordered a Behringer HD-400 Ground Loop Destroyer just in case, (which didn’t seem to help, but I think it was defective so I sent it back and am waiting for the replacement). However, when I called Behringer’s tech support, the guy I spoke with said that it sounded more like hard drive noise being picked up by the mics. And when I told him I was running them through the computer’s sound card, he suggested I look into a USB interface.

    This weekend I purchased the PreSonus 1818VSL USB interface, sure this would solve the problem. Not by a longshot. Using the AudioBox software, the AudioBox ASIO drivers, and running the headphones through the 1818, it still does it. Sometimes very loudly. The AudioBox software is a virtual mixer and when the chirping is loud (with the gain raised significantly on the inputs) it’ll register in the meters, at least three quarters of the way up. With the gain way down in normal recording range, it’ll still often do it but in a much more subtle, chirping, tinkling effect. For instance, I’ve done test recordings of my piano and didn’t notice it through the headphones when I was playing due to the volume of the live piano itself, but upon listening to the recorded tracks, it’s present, subtle at times, louder at others.

    I will add that in this particular case, I noticed it more prevalently on the second input (of three mics), though they were all running in at about the same volume. For some reason, and this might be purely coincidental, it does seem to do it more on the second input, regardless of which mic is plugged in at the time. But of course it was doing it long before I even bought the 1818 so I don’t think there’s any defect in the unit.

    Even with the phantom power off, and three mics plugged into the 1818, it started making the chirping noise. So then I decided maybe it’s the cables. I unplugged the cables so nothing was running into the 1818 and I didn’t really notice any chirping. So then I figured maybe it’s the mics (even though it’s done it with old and new mics, both dynamic and condenser.) So I plugged in a TRS cable and plugged it into my guitar. And the chirping came back!

    At least I know the mics aren’t picking up the HD noises since it does it with a guitar too. But at this point I’m thoroughly at a loss!

    If it helps, I’m running it into an HP dv7 laptop. I’ve never really had issues in the past.

    I’m guessing it’s something internal to the computer, but I don’t even know what since it does it regardless of whether I’m using the internal soundcard, drivers, or jacks, or the 1818 USB interface.

    And I should add, it doesn’t do this when I’m just listening to music, videos or anything else on the computer. It’s purely happening when sound is entering the computer in any way, and it is audible in both the headphones as it’s happening and on the final recording.

    I’d really appreciate any help on the matter! Thanks much!
  2. Boswell

    Boswell Distinguished Moderator Resource Member

    Apr 19, 2006
    Home Page:
    Do you hear the unwanted sound in the headphones when monitoring live inputs, that is, when the audio is not going through the computer, or only when monitoring through the computer?

    Can the sound occur on its own or is it present only if there is genuine audio there as well?

    Could you post a short Soundcloud clip of the effect? A sample like the one you described when the chirping was showing 3/4 way up the meters would be a good one.
  3. dvdhawk

    dvdhawk Moderator Resource Member

    Dec 18, 2008
    Western Pennsylvania, USA
    A few more questions:

    Is the noise constant, or intermittent?
    Have you swapped USB cables?
    If intermittent, where is your cell phone during all this?
  4. Todd

    Todd Guest

    Hi guys,
    Thanks for the quick responses!
    Let's see...

    Unfortunately the 1818 doesn't pass audio through the headphones unless it's connected via USB to a computer. And before I'd hooked up the 1818, I was running the audio through the mic preamp directly so there was no way to monitor it before it made it to the computer.

    The sound doesn't appear unless a cable (either mic or TRS) is plugged into either the 1818 or the soundcard mic input of the laptop. It doesn't show up when listening to any audio that's already on the computer or internet though.

    I will try to find a couple suitable clips of it and post them for you to hear tomorrow.

    It is intermittent. There are times where it'll stop entirely, and then suddenly start up and continue for a minute or so straight. I've tried moving nearby cordless phones to no real effect. I've even tried holding them near the computer to see if I can get them to make the sound. Didn't work.

    At times is has seemed like moving the cursor on the screen (either with an external mouse or the laptop's pad) has caused it to make more of the sounds, but it could be completely coincidental since again, it does it with the external mouse unplugged and me feet away from the computer playing an acoustic instrument.

    My cell is always at the other end of the house. And it's definitely not what I would consider a tell-tale cell interference sound... at least not the kind I've picked up through guitar pickups and amps and car stereos in the past.

    I haven't actually tried a different USB cable, only because the sound started long before I'd even purchased the USB interface. At that point I was running audio straight into the sound card's mic input. I could try it tomorrow. I've tried everything else!

    Thanks again for the questions and I'm be eager for any input!
  5. dvdhawk

    dvdhawk Moderator Resource Member

    Dec 18, 2008
    Western Pennsylvania, USA
    That bit of information would have me looking hard at the computer itself.

    Several years ago I had a specific USB cable that would work with everything else, except my MBox audio interface. Last year I had an intermittent noise that turned out to be caused by my phone pinging the nearest tower every few minutes. (The reason I asked the first questions) Both of those things were very evident in the waveforms.

    You said the chirps are visible on the meters at high gain, does that translate to them being visible in the recorded waveforms?

    An actual TRS (3-conductor) cable with a guitar? That could potentially be leaving the unterminated ring from the unbalanced guitar jack feeding the out-of-phase amp of the balanced TRS jack's circuitry in the interface. That's not the kind of thing that would be likely to cause all of your problems, but you may have a combination of things going on.
    kmetal likes this.
  6. Todd

    Todd Guest

    Okay guys,
    here's a video I just made with the chirping so you can hear it.

    View: https://www.youtube.com/watch?v=hLkhwDE3B0w&feature=youtu.be

    The first part of this video is the strange chirping sound being recorded when I was playing the live piano. I was using three condenser mics running through the 1818VSL for this.

    The second part is the same mics, with phantom power turned off and input gain turned up to isolate the chirping without any room noise.

    And again, this is the same noise I was getting with completely different equipment (except the actual laptop). Thanks for your consideration!

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