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MKH60/30 M/S Combo
One of the things which set sound effects recordists apart from many other professionals who record sound, is the special requirements we have for the gear we use. Case in point: microphone frequency response. I don't know how many online recording-related discussions have been derailed the moment someone asks about the feasibility of 192 kHz recording and ultrasonic capability of certain microphones as means for better sounding recordings. Countless hapless n00bs have been told off about the limits of human hearing and the dismal frequency response of most speakers and headphones. I usually pull out before it goes all tar-and-feathers; I can no longer be bothered piping up about sound design and pitch manipulation.

Most microphones supposedly useful in pro audio are not spec'ed for ultrasonic capture. Googling the phrase "ultrasonic microphone" mostly yields bat-detectors and components for 3D positioning. Famous exceptions are the Sanken CO100 and the MKH80x0 series. But maybe spec sheets don't tell the whole truth. Enter cheap electret capsules. After reading this article on a DIY solution to ultrasonic recording using Panasonic capsules, I looked at my portable Sony PCM M10 with fresh eyes. Would it's internal mics (supposedly Primo EM 172's) also be capable of ultrasonics? The datasheet isn't much help - it looks like someone took a wild guess with a pencil and a ruler. But then it dawned on me that both Earthworks and DPA use electrets in mics capable of beyond 20kHz recording. What about true condensers like the MKH series?

Ok, so It wasn't the most linear train of thoughts I have ever had, but I basically decided to test my hypothesis that ultrasonics were not a selling point when the original MKH series came out, and so was ignored in the specs. I wanted to know if my MKH60/30 combo might have that much coveted extended response.

Enter the key-jangle test.
A big reason for wanting the really hi-freq stuff is to record metal objects and then pitch those sounds down in post - it's a great way to design huge mechanical sounds that don't sound strangely dull when their pitch is lowered. So for that reason, a good test might be to jangle a few steel keys (and similar objects) in front of the mic:

This was recorded using the MKH60, at 96kHz sampling frequency. Loading it into iZotope RX, we see a lot of high-frequency action going on:
Spectrogram of key jangle test

Zooming in, it becomes obvious that those vertical spikes (the keys hitting each other) go all the way up to 40kHz and beyond. Since the brightest areas in this spectrogram correspond to the loudest frequencies, it's clear that most of the energy lies between 8-20kHz, but the sound doesn't exactly drop off dramatically in the frequencies above that:
Zoomed in on ultrasonic frequencies

Here's a clip of the same recording slowed down to a quarter of it's original speed:

Not shown (or heard) in these clips is the response of my MKH30 which was also recording at the time. Being setup in M/S, it was off-axis to the source, which would attenuate the higher frequencies to begin with, but even then there was still quite a bit going on over 20kHz (you'll have to take my word for it).
So if you own a mic from the old MKH series, you can perhaps forget your 80x0 envy for a while; at least as pertains to ultrasonic recording.

ABB robot
Earlier this year, I got the opportunity to record at a local educational institution; distinguished by the fact that it operates a number of labs and workshops containing some pretty interesting equipment:

  • A fleet of 3D-printers
  • Several industrial robots
  • Various other CNC-machines

Members of the staff there were kind enough, not only to allow me in, but also to operate the gear I wanted to record.
Do I need to say I was excited?
Of course, being an educational environment, it was there for the sake of the students - not me. This is the well-known problem always facing field-recordists; to be cheeky enough to get the sounds we want, without bothering people.

I started out in a small room containing 3 or 4 Ultimaker 2 3D-printers, of which 3 were running at the time. Many people will have heard the sounds of this type of machine, but to get 3 of them printing in the same room, with a heavy door between me and the rest of the workshop, was more than I had hoped for.
'Twas a symphony of plastic filament meltage - I swear I heard traces of a be-bop saxophone solo in that cacophony!
Have a listen:

Next up was a large, bright orange ABB IRB 6620 industrial robot - the kind you see in footage of car factories. It was located in a room of its own, which I suppose is for safety reasons and the fact that it had a fan running of some kind, which was rather noisy. I couldn't quite get the clean sounds of just the robot moving, not least because of a safety measure which prohibited movements beyond a certain (slow) speed while under manual control. It was possible to pre-program it to move faster, but then it would against the lab rules to stay in the room with the robot. Like the man said: "It could easily punch a hole in the ceiling". I became somewhat disinclined to stand at the business end of a 10-foot steel arm able to do that.
For all that, I did get some sounds that certainly sound industrial in nature:

Luckily for me they also had the smaller ABB IRB 120 robot there. This time, there was no fan noise and less safety measures. We did a bunch of single-axis movements, as well as more complex things. I suppose we all have an idea of how servos sound (think gigantic sci-fi robots), but the real deal had more to offer that I had expected. Not just the whirring and whizzing, but also little jittery, buzzing sounds - especially when the machine was idling:

Lastly, I got close to a Z√ľnd flatbed CNC cutter. This thing cuts the finest patterns into sheet materials like plastic and paper, using a tiny, sharp blade.
Again, lots of interesting whizzing and jittery sounds. Especially the calibration procedure sounded cool:

Naturally, I didn't just record these machines out of my own curiosity - but to be able to deliver their sounds to you, dear reader.
Expect them out soon; sign up for the mailing list to get a substantial release discount, and while you wait, listen to this preview:

Out now - Robotics Lab!

Here's the next sound effects library from Hzandbits - it's called Vibration.
These are nearly a hundred sounds (most of them seamless loops) created with various metal/plastic boxes and panels - and a 100w tactile transducer.
Have a listen:

Fittingly for this season, I'm just now finishing a library of very windy sounds. I've done plenty of those before, but this time, the focus is on wind through vegetation. Trees, bushes, grass and reeds get a solid stir during Danish winters, and that is what Wind In Trees is made of:

The focus is rather narrow, going for many nuances of the same flavor - rather than many flavors. If you need sounds of a storm or gale in northern European vegetation, then this should fit the bill. Note that there is audible buffeting in several files. I opted to leave it in there, as it might suit some purposes, and let me keep the most violent passages. You can try your luck with noise reduction, but since wind is mostly broadband noise anyway, it might not turn out well. YMMV.

Out very soon...

New year - new sounds.
Coming up is a collection of exterior industrial ambiances, basically the sounds escaping factories and industrial sites, making us all wonder: What're they building in there?

I've been sneaking around various locations that made sounds that were boring in an interesting way - just what you want for a scene set in an industrial location. Most of the recordings are generic enough to be used in many different settings, although a few are clearly "port-like", with Seagulls and such.
Anyway; coming soon.