Field recording

Gregg · 2020-10-31T18:25:32.446Z

I have a pair of KM84s, but no portable recording device. Will need 48V phantom power. Not so worried about cost, don’t need built in mics, but just want good quality and as small/light as possible, would the cheapest little Sound Devices be a good bet?

mnm207 · 2020-10-31T19:25:40.913Z

A Mixpre3ii from Sound Devices would be a good bet. Powering it with a USB-C powerbank or Sony L style batteries does start to push the bounds of “smallest/lightest.” I really like mine.

If internal mics aren’t a negative factor, a Tascam DR100mkiii or Sony D10 might also suit your needs–though I’d prefer the interface of the Mixpre, myself.

ahmohb · 2020-10-31T19:44:20.142Z

You’re right about the batteries with the MixPre. I really love mine but powering makes it a little more of a hassle. Have you looked at the CEntrance MixerFace Pro? I haven’t had a chance to test them but the simplicity of the MixerFace is really appealing to me.

anon60283851 · 2020-10-31T20:38:38.316Z

Ah, that sounds like a good way to start experimenting for me as well. I was thinking about getting a pair of Micbooster’s Clippys, or equivalent Lom mics - might be a cool winter project to build a pair myself instead…

(Full disclosure: I’m bad at everything as well, but at least there’s a LOT of stuff I’m bad at, so definitely interested in the results…)

anon60283851 · 2020-10-31T22:00:25.907Z

Ak-shully - noticed that Lom still have some mikroUši Pro in stock from the latest batch. I saw several discussions mentioning 1) they might be using EM258 capsules 2) in any case, they have a decent response pretty high (relatively speaking) to ultrasonic territory.

So ordered a pair of those so I can focus on other DIY projects during the winter. Now all I need is to save up for a Mixpre (3 mk2 or either generation 6) or another 192KHz portable recorder before next summer comes and the bats wake up again around here…

ermina · 2020-10-31T23:28:10.076Z

About the ORTF AE Rycote blimp with MKH8000 series mics, the MZL version is useful but not mandatory, which helps alleviate the price.
With the XLR (MZX 8000) modules, there is no room to use cables with a full size XLR plug. Also, such a plug is too heavy compared to the entire mic and for the softness of the lyres. So instead of using the MZL connbox, i made a lowprofile 2*XLR3f → XLR5m cable with lots of heat-shrink wraping.

RX704232_mkh8040_w1080×720 272 KB

It fits perfectly in the blimp with 1cm of margin. For 5 years i’ve been thinking of eventually buying the connbox and never did. I probably will if/when my cable goes wrong, because it was annoying to put together.

Hovercraft · 2020-11-01T00:00:15.492Z

If ultrasonic recording of bats is your focus, you should consider the AudioMoth. It was developed as a tool for acoustic ecology, and quite a few people are using it to record bats.

groupgets.com

AudioMoth v1.2.0

The AudioMoth is a low-cost, full-spectrum acoustic logger, based on the Silicon Labs Gecko processor range. Just like its namesake, AudioMoth can listen for sound from audible frequencies, well into ultrasonic frequencies. It is capable of recording...

PRICE PER ONE AUDIOMOTH DEVICE (BATTERIES, SD...: $59.99

anon60283851 · 2020-11-01T10:02:48.866Z

I had somehow completely missed that during all the googling, thank you! For “batspotting” I suppose it still makes sense to have a normal portable recorder, but one of those with the waterproof case would be superb for relatives’ log cabin or one of the other known spots where bats are regular visitors…

zoundsabar · 2020-11-04T21:45:40.528Z

In the last couple of months I’ve been playing with the AudioMoth v1.1.0, which is almost identical to the one linked by @Hovercraft, but has slightly worse audio specs compared to the very new v1.2.0. The device is brilliant in many ways. It can be set up to record when triggered when sounds of a certain level and/or frequency occur, or on a schedule you can set. Or it can be switched on and it will record manually. It is very compact and does indeed have a wide frequency range. It’s a recorder with an omni mic built in, so it’s self contained. I got four of them and have been using them so much that I got the custom cases for them that cost almost as much as the recorders.

I’ve been playing with very widely spaced omnis with them, from 10 to 50 feet apart, in various quad patterns in different exterior locations, suburban and in nature. They make that exercise about as convenient as possible. I get them all started, do a sync clap while there are all together beside me, then place the mics in whatever array I want to play with. When I’m done I can just collect them all, turn them off, remove the micro SD cards and copy them to my computer where I line them up using the claps in Pro Tools. Absolute sync accuracy isn’t important since the mics are so widely spaced that higher frequency inter microphone phase information is overwhelmed by the distances between the mics. There are some interesting delay effects between channels when listening back in quad. Sounds that are between the mics have a different quality to sounds outside the mics. When birds fly around or gusts of wind pass around they give a marvelous spaciousness to the sound field.

The downsides of the AudioMoth are several. They are a bit noisy, so not suited to recording very quiet ambiences. And they overload easily. Wind can be a problem, not sure how to shield them yet. They don’t have a wide enough range of preamp gain adjustments or pads to avoid overloading the mic on close, loud sounds. You have to set the mic and auto record settings up from an app that runs on the computer with the AudioMoth connected by USB. It’s impossible to listen through the AudioMoth with headphones to hear what you will be getting. But for recording sounds in a mid range of levels with very flexible cord free placement options, they are great.

I haven’t yet tried to record ultrasonic sounds with them, so I can’t comment on that. Subjectively I’d say they have plenty of airy highs in the recordings I’ve been making, but may be slightly weak in the lows, but not too bad. EQ can help with any such lack.

image1134×1297 98.7 KB

nonsmeddy · 2020-11-05T23:15:43.738Z

Right on cue, the Vermont Center for Ecostudies newsletter informs me that their vernal pool monitoring project is using AudioMoths, which includes a link to an iNaturalist observation (recording) of a Big Brown Bat; the screenshot on that page doesn’t show it but you can download the original recording to find that at 384kHz/16bit, it’s capturing overtones right up to the Nyquist limit:

Screen Shot 2020-11-05 at 6.11.34 PM2874×556 699 KB

Not sure but I guess that’s 1.1.0. I am, to say the least, intrigued.

zoundsabar · 2020-11-06T01:18:39.951Z

That’s a lot of highs! Beautiful. Would be interesting if varispeeded down.

timp · 2020-11-09T03:56:36.929Z

Do you find there is sync drift between the recorders? It would be valuable to record a clap at the end of the recording too, to verify

zoundsabar · 2020-11-09T18:28:07.897Z

Hi @timp. I made a stereo recording yesterday with head and tail claps. The recording was 249,708,422 samples long (01:26:42:06 at 24fps). There was a drift between the two recorders by the end, but it is extremely slight: 1,913 samples drift (.04 second or .0016 frames). That’s equivalent to a 0.00000766% rate of drift. I believe that that is insignificant for widely spaced usages, but not good enough for accurate recording of phase related differences for higher frequencies in closely spaced recordings.

(Edited to add the following. I’m not sure how these links will work in this forum.)

I adjusted the sync on the 2 mono files to a compromise position about half way (956 samples) between the head and tail claps.

Here’s a link to part of the wav file on my dropbox if anyone is interested in listening. It’s not the most dramatic thing I’ve recorded. (255 MB file)

This 14:40 chunk from around the middle of the 86 minute long file. Recorded on a windy afternoon in the backyard, under a redwood tree, with the AudioMoths in their bespoke plastic cases, but with no wind protection. In the distance you can hear footsteps on dirt and gravel of someone hanging clothes on the line. The microphones were about 2 meters apart.

I need to find a way to protect these mics from the wind. I’m thinking of a foam cover for the microphone end of the box, inside a furry sack.

Here’s a more interesting wav quad recording of crows settling in for their night roost made with the mics placed in a rectangle about 5 x 7 meters apart, with the longer dimension between the front and rear. I like the sense of spaciousness given by the widely spaced mics. It would be best heard in a cinema-like space, with widely spaced speakers. There aren’t any phase or mono compatibility issues, but there are audible delays between the channels that add to the spaciousness. (258 MB file)

These links are not guaranteed to work forever!

Here are dropbox “transfer” links which may work to download the files. These are only good for 7 days (until 2020-16-09).

Dropbox

D Murray sent you 1 item

Stereo Demo Windy Aftrenoon.wav

Dropbox

D Murray sent you 1 item

Quad Demo Crow Night Roost.wav

LFSaw · 2020-11-09T21:58:40.608Z

Dear Field Recording community on the lines forum. As an enthusiast in collecting sounds inside and outside, with microphones, hydrophones, contact microphones and other material, I am (as always and again on this forum) very intrigued by the way how people are treating each other with respect and are super constructive. In this spirit, I’d like to point your attention to this little nag I have with some of the discussion:

Every now and then I read about “the wilderness” and that people are disappointed (?) that they can hardly find places where there are no planes crossing. You probably know this already, however, I find this quite important to have in mind when collecting sounds: The notion of “wilderness” has a very controversial historical background and is IMHO very difficult in its appearance. I’d like to invite you to read what Chief Luther Standing Bear had to say about the wilderness term around 1933:

We did not think of the great open plains, the beautiful rolling hills, and winding streams with tangled growth, as “wild.” Only to the white man was nature a “wilderness” and only to him was the land “infested” with “wild” animals and “savage” people. To us it was tame. Earth was bountiful and we were surrounded with the blessings of the Great Mystery. Not until the hairy man from the east came and with brutal frenzy heaped injustices upon us and the families we loved was it “wild” for us. When the very animals of the forest began fleeing from his approach, then it was that for us the “Wild West” began.

This Quote of Chief Standing Bear is part of his Book Land of the Spotted Eagle and re-appears e.g. in this detailed paper:

faculty.washington.edu

Callicott%20Contemporary%20Criticisms.pdf

The Great New Wilderness Debate

The Great New Wilderness Debate is an expansive, wide-ranging collection that addresses the pivotal environmental issues of the modern era. This eclectic volume on the varied constructions of “wilderness” reveals the recent controversies that...

For me, this description and perspective turns the idea of collecting sounds into a totally different light: It becomes less an activity to find isolated sounds that I find beautiful, moreover, it becomes a practice to appreciate what is already there…
Listen e.g. to the (faint background) noise of what I think is a construction site in this recording:

IMHO it considerably adds to the mood of the piece.

I would be interested in your opinions on both, the general remark I made and also (of course but not primarily ) on my recording(s).

timp · 2020-11-09T22:41:13.256Z

Thanks for link - I have downloaded and will have a listen this evening - I am interested to get a few audio moths for a project, great to hear these recordings.

Not sure if it is of use, but for correcting drift one option could be via technique we used to use for converting film mixes between frame rates… (With caveat it is via ProTools, I dont know what other DAWS support it) in PT you can display the timeline units in samples (rather than timecode, tempo/bars/beats etc) which means can then measure file or region length in samples and use sample count for calculations (as you did) to calculate exact correction ratios… Simple ratios like 24fps > 25fps are easy maths but for small amounts of drift you can also copy/paste sample length measurements directly into the Time Compression plugin (or Serato’s Pitch N Time) data fields.

zoundsabar · 2020-11-09T23:15:21.505Z

Thanks for the interest in the sounds, and also for the tip. I use Pro Tools and Pitch n Time Pro, and I’ll try that out.

ermina · 2020-11-10T00:42:33.994Z

i “record in the field” as a part of my listening practice (maybe a visual analogy would be: take a walk outside. Snap some polaroid pictures. Later, use the color masses on the pictures as a basis for some parts of a painting) Of course, I will use mic/body positioning to re-balance “existing sounds”. Later on, cutting, filtering, or worse may happen.
Anyways , I don’t think of “nature” as a place to harvest isolated sounds from, but i can conceive there are cases when it’s an obvious approach (documenting specific aspects of human and animal life, making precise figurative sounds for use in larger audiovisual works, etc).

I think planes are a special case of sound in the field. They are annoying because/when they expand the referential too far away from the location where recording takes place.

A distant noisy motorcyle, sure. There’s a road somewhere that draws a line through the place. Not too many people use it, But it’s there and sometimes a presence makes it bright. It means something.
Huge constant traffic drone, yes. That is a manifestation of organization. It’s there as much as the larks. The autobahn structures the territory. It isolates two sides while connecting points. It is a defining feature of the land.
But planes are indifferent to the place they fly over. They are unpredictable but will easily overpower small sounds inhabiting a quiet spot; maybe not enough to stop these from happening, but enough to distract a listener, to shift the focus and superimpose the inescapable and constant predation of the world over the recorded place. I hope* some kind of silent airship will replace the jetliners soon.
Maybe i’m basically repeating the old “pure-nature vs modern-mankind” trope that i dislike so much about the first soundscape theorists, by shifting it where it feels less dissonant ?

* lol

makamqore · 2020-11-10T05:39:27.746Z

Great points LFSaw, reminds me of the difference between landscape photographers (like Ansel Adams) for whom “nature” obligatorily would index a mythical pre-human timelessness (ignoring, as we know, that many such landscapes had already been repeatedly transformed by people Indigenous and settler-colonial)—and documentary photographers who strive to capture the world “as it is.” I’ve always preferred the latter if I’m going to take a photo (I’m interested in shapes and forms that I encounter but didn’t intervene in “making” myself) or make a field recording. And I agree that the hum in “bridge from above” in your linked recording adds to the mood!

anon60283851 · 2020-11-10T08:48:02.190Z

It’s really an interesting point of discussion, thanks LFSaw.

In my view the whole “I want to find untouched nature without any airplane noises or freeways” vs. “I want to record what comes my way” distinction is (obviously) not entirely black and white or either-or. For me it can be either: going somewhere trying to find a place where I can record something I want to, hoping that there’s nothing else that will mess up that particular mood - be that a freeway and planes flying over, or wind & birds with minimal freeway or airplanes in the background. Or alternatively, going somewhere and just recording what is there, appreciating what comes.

I suppose I approach this more like a musician / bedroom sound designer rather a “field recordist” would: it’s less about the philosophy of capturing soundscapes, and more about the act: either trying to capture something specific I have (an idealized version of) in mind, or just going somewhere and letting lucky accidents happen by recording what’s there at that point. Either is a good way.

As far as the terminology goes, I tend sort of throw around terms in a language that’s sort of familiar to me, thinking that I know what they mean / imply. But obviously the english word “wilderness” has an entirely different cultural connotation than the roughly equivalent term in my native language (come to think of it, the first direct translation that came to mind does have sort of an pompous, idealized edge to it). So there may be something that gets lost in the translation as well.

LFSaw · 2020-11-10T08:51:03.333Z

ermina:

But planes are indifferent to the place they fly over. They are unpredictable but will easily overpower small sounds inhabiting a quiet spot; maybe not enough to stop these from happening, but enough to distract a listener, to shift the focus and superimpose the inescapable and constant predation of the world over the recorded place.

you make a good point here, I have to think about that one… it is like something (the plane, in this case) escapes the intended framing/composition. at the same time, planes are part of our way at interfering with our environment, they form the place we record, although being indifferent to their (ground) surrounding… so if a plane disturbs, it might need to be put into the right perspective instead (focus on it, make it prominent in the recording…)?