Yet Another Pro-One Filter Sweep

I have been using my Sequential Circuits Pro-One in the studio pretty often recently, so I decided to use it instead of of a newer keyboard for a recent performance. Unfortunately it did not work the way I had planned. Although I crave unpredictable behavior to stimulate the creative process, it is not exactly as pleasing during a live performance. The aging instrument did not stay in tune for very long and I was having trouble with the keyboard action. I imagine that it’s time for a thorough cleaning of the potentiometers and keyboard contacts. Despite these troubles, while scanning through clips recorded during the set, I came across this nice low frequency filter sweep and ran it through a ping pong delay.

Pro-One Filter Sweep

Caution. Moving Walk is Nearing its End.

One of the nine forms of transportation I did not include in the compilation from a couple of entries ago was the moving walkway. On the way home from Seattle last Sunday I had a little extra time due to a delayed flight, so I used it to capture some more airport ambiance including the moving walkway. This one is located in the Seattle-Tacoma International Airport. The best part of the recording is the automated pre-recorded warning as passengers near the end of the walkway. The exact wording is, “Caution. moving walk is nearing its end. Please watch your step. Thank You.”

Moving Walkway

Time Stretched Dog Bark on the PCM-D50

I time stretched this recording of my dog Tia barking on the PCM-D50 using the built in DPC or Digital Pitch Control. I don’t know why they call it pitch control when it doesn’t change the pitch, but rather time compresses or expands the audio by percentages, from -75% to +100%. The intent is for musicians to practice difficult passages, but I think it has a nice eerie, metallic effect on voice and other sounds. For comparison I’ve posted her barking with out the time expansion as well.

Original Dog Bark

Time Expanded Dog Bark

Normalized Binaural Back Alley Ambiance

One of the very first tests I made using my DIY binaural mics was this example of back alley ambiance. I stood as still as possible because this first version of the headset had a stiff cable that was very sensitive to vibrations. Birds and traffic are the most obvious sounds, but there is a high pitched screeching going on throughout the recording that became even more noticeable after applying normalization. While making the recording I actually took the mics out of my ears to make sure they weren’t generating the tone and I knew I wasn’t going crazy when it turned up in the recording. The sound is either a near by train, or a neighbor using a power tool. It sounds more like a tool, but the freight trains that go through my neighborhood make some very similar sounds to this.

Binaural Back Alley Ambiance

Roll Your Own Binaural Microphone

First of all, thanks to Leafcutter John for encouraging me to look into binaural recording. As a result I spent most of last Sunday designing and building a set of binaural microphones. What’s surprising is that I had everything I needed in my home. I started with a couple of old Mac computer mics that my friend Kevin gave me a few weeks ago. I tore them apart and removed the electret capsules from the circuit boards. I found a set of silicone ear-buds from an old mobile phone headset that fit the capsules perfectly. After that it was pretty easy.

On my first attempt I used the cabling from an old set of airline headphones, but the stiff wire going from the right to the left microphone was too sensitive to vibrations. After all that work I decided to disassemble it and start again. This time I sacrificed an old pair of JVC headphones. The cabling was much better and had separate cables to each driver. This time I used a paper hole punch to modify the ear-buds so the back of the capsules weren’t stuck in a vacuum. I used colored heat shrink to specify left and right, added a tiny bit of foam between the capsule and the ear-bud, then mounted a couple of layers of foam over the outside.

I was pleasantly surprised by the few test recordings I made. For the majority of the tests I placed the ear-buds into my ears and kept as still as possible since the mics are quite sensitive while plugged into the Sony PCM-D50. I ended up using the 20dB pad, although I got a better sound without the low cutoff filter enabled. For some other examples visit this post on Leafcutter John’s blog.

Binaural Finger Snaps