Removing hiss from microphone after a workaround for lack of mic input on camera

Discussion in 'Digital Audio' started by Gregintosh, Apr 27, 2010.

  1. Gregintosh macrumors 68000

    Joined:
    Jan 29, 2008
    Location:
    Chicago
    #1
    Hey guys,

    I am in the process of putting together a few videos. Here's some background which may assist. If you do not feel like reading it, that's fine, simply skip to the bolded heading of "AND HERE IS THE PROBLEM"

    The videos are essentially going to be one person talking on a green screen background. No fancy camera angles, not even zooms or anything. Just one person talking for about a minute and a half.

    I have a Sony HDR-CX110 HD video camera. It produces fantastic video quality (pretty much blu-ray quality outdoors or indoors with proper lighting). The problem is the audio.

    It only has a built-in stereo mic, which isn't bad for home movies and such, but is terrible for more "professional" applications.

    Now, I do have a lavaliere mic (audio-technica ATR3350). Unfortunately, the camera being a consumer-grade HD camera does not have a mic input. The only camera I found with one is the Kodak Zi8 which has terrible video quality (3 out of 10 IMO) compared to the Sony (9 out of 10).

    So what I have decided to do is hook up the mic directly to my iMac (Aluminum 2007 Model, using iMic from Griffin as the input as there is no mic jack on this iMac that I am aware of) and record the audio using Garageband. This is made possible by the 20 foot cord of the microphone.

    Then I plan to edit the movie in iMovie (basically, use the green screen to give me the desired backgrounds throughout the clip). Once this is done, I will import the movie into GarageBand, where I plan to mute the audio from the video source, and simply play the audio I recorded directly into Garageband during the shoot.

    I have tested this with a few sample clips I recorded and I have been able to synch the lips up to the separately recorded audio perfectly.

    Now that you have the complete background....

    AND HERE IS THE PROBLEM

    The problem is that the audio recorded directly into GarageBand with the Audio-Technica mic has a bit of a hiss. I have tried playing with some of the effects and it seems like some of them mute the hiss a bit, but none eliminate it.

    My question is, what can I do to eliminate the hiss? I had an M-Audio microphone that cost around a $100 which did not produce the hiss IIRC. It is mostly audible if I turn up my iMac's speakers halfway up or higher.

    Does GarageBand have some sort of filers or settings that get rid of it? Is this something that will always occur on a mic that uses an analog input? (The M-Audio was a USB mic)? Am I just being a perfectionist and this kind of hiss is normal when you turn the speakers up on any video?

    Thanks!
     
  2. scottlinux macrumors 6502a

    scottlinux

    Joined:
    Sep 21, 2005
    #2
  3. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #3
    Audacity's hiss filters are pretty good...

    As an aside, how much hiss was there? Is it possible you were pre-amping the mic twice (that is, that mic seems to have an in-line pre-amp in the cable, from what I can tell, and then the iMic also pre-amps if you use the Mic port)? This would probably result in a fair amount of hiss. If the mic indeed has a pre-amp in it (e.g., if you have to put a battery in that little plastic case that's on the cabling), then try plugging it into your iMic's line-in instead of its Mic port.
     
  4. Gregintosh thread starter macrumors 68000

    Joined:
    Jan 29, 2008
    Location:
    Chicago
    #4
    Thanks guys! I tried both things. Audacity removed the hiss perfectly from the audio that I had recorded for my test video.

    As far as capturing the audio without hiss, I tried switching the iMic to Line mode instead of Mic, but that only brought the volume down of the audio, and when turned up it actually produced more hiss than before. So it seems like the Mic input is the only semi-decently working one.

    I guess what I will do is load the video into garageband, match up the originally recorded track with the garageband recorded one (with some hiss but still 100x better than the camcorder mic), then export the video.

    Then I will use Audacity to remove the hiss from the video directly, export the audio file back into Garageband (since it will match the length of the video it will already be synched up to the lips) and export the video again for DVD or YouTube.

    A bit of work, but it should get the job done and it certainly beats spending $1,500+ on a professional camera with mic inputs (or degrading my video quality to opt for the Kodak Zi8). Why they don't put mic inputs on ALL camcorders is really beyond me. That should be a standard feature!

    THANKS GUYS!!!
     
  5. hakukani macrumors regular

    Joined:
    Feb 9, 2008
    Location:
    Hawaii
  6. firewood macrumors 604

    Joined:
    Jul 29, 2003
    Location:
    Silicon Valley
    #6
  7. hakukani macrumors regular

    Joined:
    Feb 9, 2008
    Location:
    Hawaii
    #7
    USB mikes are fine for your purpose, but they are kind of a one trick pony. With an interface you can pick the mic for the job. So, you could have a good stand mic or a lavelier.
     

Share This Page