Heavy footsteps in audio

Discussion in 'Badminton Photography' started by Gollum, Jan 30, 2017.

  1. Gollum

    Gollum Regular Member

    Joined:
    May 23, 2003
    Messages:
    4,642
    Likes Received:
    286
    Location:
    Surrey, UK
    My microphone seems to think I am the Hulk.

    When I'm recording demonstrations on court, the sound of footsteps is often loud and bassy. You know, the kind of exaggerated bass you get in films where something hits the floor dramatically -- like the One Ring, or a badass hero / villain stepping out of a car while the camera looks at their shoes.

    I have tried adjusting this in post production, but it my efforts so far have made the whole audio sound very thin (I used parametric equalisation to try reducing low frequencies). And the footsteps are still oddly heavy even after this drastic interference.

    I'm not sure why this happens. Vibrations through the floor maybe? It's a sprung wooden floor. I'm actually quite light, and while my footwork is far from perfect, I wouldn't describe myself as stompy. Also we had the same issue when we were using a large boom instead, which I would have thought would dampen any vibrations.

    I am recording with two microphones: a medium shotgun on the camera, and a large shotgun on a stand. It seems that most of the bass is coming from the big mic, which does pick up bass better (the other one is a bit tinny on its own).

    One solution might be to just remove/reduce the big mic audio volume (in post). But I am curious whether anyone has some insight into what's going on. Maybe there is some trick I'm missing.
     
  2. s_mair

    s_mair Regular Member

    Joined:
    Oct 10, 2013
    Messages:
    4,152
    Likes Received:
    2,445
    Location:
    Germany
    What could be happening is that the bass frequencies are transferred from the floor to the mic stand and directly fed into the mic (body-bourne sound). The effect might be even more dramatic, if the resonance frequency of the stand is hit by the frequency coming from your footsteps. You could try to put pieces of neoprene or other closed-cell foam material under the feet of the stand and see if the effect is reduced.

    If not, then it should be not a big deal to fix this with equalization. First of all, use a low-cut filter at around 100 Hz or even a bit higher. This should not affect the understandability of your voice (which should be the crucial point). If that's not enough, go on with reducing even more lower frequencies.

    Perfect thing to have would be a graphical frequency analyzer that would indicate the peak frequencies so you can specifically set the equalizer to cut the peaks. Although I doubt that non-pro video editing software offers that.

    In general, there is one magical tool to dramatically improve the overall sound quality and make it sound more even and more full: A compressor (https://en.wikipedia.org/wiki/Dynamic_range_compression). Any chance that your video software offers that?
     
    Gollum likes this.
  3. Gollum

    Gollum Regular Member

    Joined:
    May 23, 2003
    Messages:
    4,642
    Likes Received:
    286
    Location:
    Surrey, UK
    Good idea, we should try that. Thanks. :)


    I'm using Adobe Audition (albeit an old version, CS 5.5), so I suspect the software is perfectly capable. But I am no audio engineer.

    I did try equalisation, but maybe I can try again. I will have a go at cutting off around 100 Hz, instead of using the "smoother" parametric equalisation.

    I also tried compressing the audio, although that was mainly with the idea of boosting the volume. I used the multi-band compressor in Audition. The trouble is, I don't really know what I'm doing! I'm sure a skilled person could make the audio sound better with compression, but I don't know whether I can.

    One issue is that compression evens out the audio levels, making loud sounds quieter or quiet sounds louder. This is not necessarily desirable when you have some background noise, as you end up making it louder relative to the speech.

    All tips gratefully received, thank you! :)
     
  4. s_mair

    s_mair Regular Member

    Joined:
    Oct 10, 2013
    Messages:
    4,152
    Likes Received:
    2,445
    Location:
    Germany
    Finding the right settings for audio compression is always the critical point and requires a lot of trial and error. So it's really hard to almost impossible to give any proper advice or setting proposals since it totally depends on the material you are working with. Especially if you are dealing with a complex multiband compressor - there is a high chance that you end up with a worse result than before. And if the plug-in in Audition offers all the stuff that is shown in here (https://helpx.adobe.com/audition/using/amplitude-compression-effects.html), then this is a really mighty tool. Wow.

    A quick google search showed me this page, which might be a starting point for you:
    https://larryjordan.com/articles/audition-multiband-compressor/

    In general, try some of the presets that the module is offering. If you get one that is intended for speech, you should be on the right track. Bass frequencies should remain untouched or even reduced, the human vocal frequencies should be boosted. And whatever you do, make sure that you are not overdoing the boosting - as you have already said, you will boost the former quiet noises so much that the whole material will sound really weird.
     
  5. Gollum

    Gollum Regular Member

    Joined:
    May 23, 2003
    Messages:
    4,642
    Likes Received:
    286
    Location:
    Surrey, UK
    Yep, that's the one! With this sort of tool I feel like a caveman prodding an obelisk from space. ;)

    It's the same problem with After Effects. Even the older version I have is good enough for working on Hollywood blockbusters. But more than any other software I've used (and I have used a lot), After Effects feels like voodoo. I often have no idea where to start, and this is coming from someone who used to do 3d animation as a hobby.

    I'm sure I could teach myself some skills here, but it's a matter of time. When I was 13 I would have lapped it up. I mainly want to do stuff like drawing arrows and circles under my feet -- but it would be nice to make it look good.

    Also some of this stuff eats your average computer alive. I'm not even sure my current PC is fast enough to use some rotoscoping tools in AE. Last time I tried on an older PC, After Effects just crushed it.


    Thanks, that's good advice. I shall make another attempt! :)
     
  6. s_mair

    s_mair Regular Member

    Joined:
    Oct 10, 2013
    Messages:
    4,152
    Likes Received:
    2,445
    Location:
    Germany
    I'm still having a 6(?) years old iMac at home and video editing clearly is the worst you can do to a not up-to-date computer. Even cutting and rendering with iMovie is pure nightmare and takes ages (and the effects sometimes look as if they were done with Microsoft Word). So I'm not even thinking about torturing it with After Effects and stuff.

    For audio recording it still does the job okay, even with today's Logic Pro. As long as I'm not trying to record more than 4 channels in parallel of course.

    Anyway, let me know if you get some better results after toying around with the compressor and equalizer.
     

Share This Page