Tagged: Experiments

San Francisco Fog Horns

On the same trip that I made the Wave Organ recordings, I woke up in the middle of the night to hear fog horns off the coast. Even in a North Beach hotel room, the sound was clear.

Bay Bridge, San Francisco

Bay Bridge, San Francisco
Photo by Tom Campbell

In the first recording, you’ll hear some vehicles on the street, and also the constant low-pitched rumble of the climate control system in the building next door:

Play 1. Foghorns

The second recording is an odd, warbly version of the same file with a noise removal filter applied — my attempt to remove the ambient machine noise:

Play 2. Foghorns - Noise Filter Oddness

This serves as a cautionary example of what can happen when you get carried away trying to “fix” recordings with software. (In this case I was using Audacity’s noise removal capability — not the fault of Audacity, just a user with an itchy slider finger.) File this one under Happy Accidents.


Garden Stake

Recently I recorded a sound I’ve wanted to capture for a long time: a metal garden stake reverberating when bounced on concrete. To get the microphones close enough to get a decent recording, I clipped some small cardiods to an inverted tomato cage, pointing inwards, and bounced the stake on a concrete floor between the mics.

As an added bonus, when I bumped the cage, the mics picked up the vibrations, causing some startling booms and scraping noises.

I’m going to explore these sounds later in another post or two, but for now here are the raw, unadorned sounds of the garden stake and tomato cage, as captured on a hot summer day.

Play 1. Stake and Cage

Recording Notes: MicroTrack II CF recorder, clip-on stereo cardioid microphones

Not Quite All Blues

To see just how much one of my favorite iPhone apps can change audio input in real time, I played “All Blues” by Miles Davis* on the piano, recording it with Loopordist, an RjDj scene by Christian Haudej.

It was quite odd, trying to play the tune correctly while listening in my earbuds to this wacky alternate version as it was generated on the fly by Loopordist. Probably not a practice method too many piano teachers would endorse!

Play 1. All Blues (Loopordist)

* Note: If you don’t own a recording of Miles Davis playing this song, treat yourself to a copy of Kind of Blue, the timeless 1959 album by this great jazz master and his sextet.

Recording Notes: iPhone, RJDJ with Loopordist scene

Inside Fizzy Water: An Audio Experiment


What does it sound like inside a glass of water after an effervescent tablet is dropped in? Using a homemade waterproof contact microphone, Okrasonic.com finds out!


A few years ago, I decided to make a contact microphone based on instructions found online. (For example, a couple of good tutorials are here and here. For a deeper dive, check out this Instructables page.) Immersing it in a synthetic rubber coating made it waterproof.

Just last week I got around to making my first aquatic recordings with this little gizmo, plunging it into a glass of water and dropping in a “zesty orange” effervescent tablet.

Here’s a video depicting the maiden voyage of my submersible contact microphone:

Inside Fizzy Water: Audio Experiment from Tom Campbell on Vimeo.

If you have trouble viewing the video above, try this link. It’s also on YouTube.

Recording Notes: MicroTrack II CF recorder, contact microphone

Space Piano No. 1

For this track I just played a few chords on an upright piano while the RJDJ Start scene was running on my iPhone. (Note: RJDJ is sadly now defunct, but it was a super fun audio toy while it lasted.)

      1. Space Piano No. 1

Recording Notes: iPhone, RJDJ with Start scene

Hammering and Blue Jays

Recorded with RJDJ using the Echolon scene, near a house construction site. A few guys were hammering on the roof, and the blue jays added to the mix on a warm spring day. Thanks to RJDJ and Echolon, there’s an echoplex effect.

      1. Hammering and Blue Jays

Recording Notes: iPhone, RJDJ with Echolon scene
%d bloggers like this: