The View Up Here

Random scribblings about kites, photography, machining, and anything else

A Self-Contained Stereo Field Recording Setup

Posted by Tom Benedict on 16/06/2016

A project I’ve been working on more or less led me by the nose toward a type of field recording I really enjoy doing. The project requires relatively long recordings of an ambient soundscape – an hour or longer. The recordings must be in stereo, and ideally serve to put the listener in the soundscape as completely as possible.

Because I can never really stop making noise, especially now that I’ve developed some rather energetic motor and vocal tics, the only way I’ve been able to pull this off is to set up my gear, leave it for an extended period, and recover it later. This drop and recover technique works great for these extended soundscape recordings. But because I often have to hike in for an hour or more to reach the locations I record in I’ve tried to shrink the setup as much as possible, resulting in a relatively compact arrangement. Here’s what I’m using at the moment:

Self Contained Stereo Recording - Front

It’s a self-built pseudo-SASS microphone array sitting on top of a vibration isolator that was made for attaching cameras to multirotors, which is then attached to my Tascam DR-70D recorder.

The vibration isolator took some modification to make it work for this application. I added a plate to the bottom that has a 1/4″-20 threaded hole in it. This lets it mount to practically any tripod or light stand, or to the top of my DR-70D using the camera attachment that came with it. The top of the mount had a 1/4″ through hole in it, but I had to make a big aluminum thumbscrew so I could thread it onto my DIY-SASS. It’s barely visible between the rubber balls on the shock mount in the photo above.

Self Contained Stereo Recording - Rear Quarter
In order for the shock isolator to work well I needed to use very flexible XLR cables to connect the mics to the recorder. And to keep things compact I needed them to be short. These are two things that make for some really hard to find cables. So like most of my gear I rolled my own.

The connectors are all from Neutrik and the cable is some leftover Mogami cable I had from building other sound bits. I really like the right angle female Neutrik connectors. They’re just as easy to use as the straight variety, and you can set the angle at which the cable comes out of the plug when you build the cable. I set mine to come out 45 degrees to the right to make the cable run a little cleaner and to clear the controls on my recorder.

Self Contained Stereo Recording - Back

The whole thing acts like a big wooden bobble-head doll. There’s not a lot of damping in the isolator, just a lot of spring, so once you thwack it it bounces around for a while. I’ll have to see how that works out in the field. Just testing indoors, though, the isolator does a good job of minimizing coupling between the tripod legs and the microphones. This should help minimize noise from grass, twigs, and branches that tap against the tripod legs during a recording. (This naturally occurring handling noise has ruined several recordings I’ve made in the past.)

The one obvious problem with this setup is that there’s no real way to monitor while recording. But since I’m leaving my gear in the field and walking away from it, it’s not really an issue for me.

I’m still working on wind protection. For light wind I have a lycra slip cover that goes over the pseudo-SASS. But for stronger wind I’ll need something more involved. (Hey, more problems to solve! My favorite!)

Tom

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8 Responses to “A Self-Contained Stereo Field Recording Setup”

  1. Greg Allen said

    Tom, I just wanted to say thanks for the inspiring blog. Your work has helped me design my own SASS and I will be using a similar dampening system.

    https://scontent.fsnc1-1.fna.fbcdn.net/v/t1.0-9/13920788_10210207258557481_3741921890629588894_n.jpg?oh=c6f4bef2080f5d53ed482b1e0816f24a&oe=58580D61

    https://scontent.fsnc1-1.fna.fbcdn.net/v/t1.0-9/13932697_10210207258597482_2850138483790918359_n.jpg?oh=fb104e02e93ee71d825bea5022a7adfb&oe=585B1BCC

    As an audio engineer I know how important quality preamps and microphones are. In the near future provided I continue to capture sounds other than those in the studio I am planning to invest in a Sound Devices recorder and better mics…

    Cheers,
    Greg

    • Tom Benedict said

      That’s awesome! That’s a beautiful piece of work. Thanks for sharing your pictures.

      I’m hoping to upgrade my recorder in the not too distant future, too. A Sound Devices is still out of my reach, but I’m looking.

      Cheers!

      Tom

      • Greg Allen said

        Tom,

        Have you seen the new Zoom F4? It is already in my shopping cart at B&H. 🙂

        Greg

      • Tom Benedict said

        Ooooh no! I’d seen the F8, but not the F4. This may change what I want to do next with my gear. Thanks!

      • Greg Allen said

        Yeah Tom, this one has me pretty excited. It’s affordable with really clean preamps. I am planning to order a couple of the Rode NT1 mics with it. They have an almost flat frequency response, only 4.5db of self noise, and being large diaphragm they should be more sensitive than smaller diaphragm mics. Set up in ORTF with a foam (cut yoga block) partition recorded to the F4 should yield some amazing results… The anticipation grows…

        Cheers,
        Greg

      • Tom Benedict said

        Looking forward to it!

        I’m also eyeing the F8. It costs more, of course, and has more channels but it looks like it’s got the same preamps as the F4. I just need to figure out if I’d actually use eight channels, or if four is a better match for what I’m planning to do long-term.

        I’m eager to hear how the NT1 mics work out in ORTF. I was also looking at the Audio Technica 4022 omnis for use in an SASS. Small diaphragm, but similarly low self-noise.

        Cheers!
        Tom

  2. Greg Allen said

    Hey Tom!

    So I have a couple extra EM-172 mics and enough components to make another SASS. This time however I am thinking about a miniature version not much larger than the shock mount. The idea will be to discreetly record ambient noise in locations such as restaurants and other public locations. At this point I’ll probably just scale everything down including the XLR jacks which will be the mini versions. Do you have any suggestions that might improve performance such as mic angle?

    Cheers,
    Greg

    • Tom Benedict said

      I really don’t. Some of the acoustic amplification of the SASS comes from the boundary effect of the mics being flush with the boundaries. If you build a smaller one, the cut-on frequency for the amplification will go up, so it may sound a little more sharp than a larger one.

      Something I’ve been toying around with that might also work is a miniature Jecklin Disc. I was walking around the local kitchen supply store recently, and saw some strainers that looked just about the right size. I wanted to try putting a baffle between two of them, mounting mics on either side, and covering them with strainers. Have that sticking out of a bag and drape a light fleece over it, and it’s a really nice stealth setup.

      But I don’t know how shrinking a Jecklin Disc will affect the sound any more than how shrinking an SASS will affect things, so it’d be an experiment either way.

      Come to think of it, I think Curt Olson made a miniature SASS out of a 2×4. Yep! Here it is:

      http://www.trackseventeen.com/mic_rigs_2.html

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