Audio Cookbook

Chlorobenzene Mistfall

It’s been a while since I have posted a rough mix, or musical idea for the One Sound Every Day category, so here’s an excerpt from something I wrote recently. It’s in very early stages, but has a high melody in 3/4 time along with some lower melodies in harmony with each other. The lower pitches are made up of the Rhodes Feedback that I posted an example of yesterday.

I cut up the feedback into sections that had specific qualities I was after, then I pitched them so that they worked underneath the high melody played on the Rhodes at an upper octave. Finally, after a couple of run throughs, I arranged the pitched feedback in real-time to form the passages heard in the excerpt.

Chlorobenzene Mistfall

Rhodes Feedback

In order to get this example of feedback I ran my suitcase model Rhodes, which I confine to my studio, through an outboard processor with some nice amp modeling and cranked up the gain. For the processing I used an eleven year old Yamaha A3000 sampler. The A3000 allows you to edit and apply processing to an incoming signal and it has some pretty nice sounding effects. Once I had adjusted the processing I held down the sustain pedal on the Rhodes and let the amplification do the rest. Tapping or gently knocking the instrument also produced some nice sounds. Here’s a snippet of the results.

Rhodes Feedback

The Smallest Sample on ACB

This tiny sample of audio represents the instant that my iPod ran out of battery life while recording a performance of myself, Nils Westdal and Graham O’Brien on drums from Monday, November 17, 2008 at Cafe Barbette in Minneapolis.

Typically when a recording is interrupted due to power loss on a digital recorder, the device is unable to save the document properly so what you end up with is a corrupt file, or worse, nothing at all. In my case I ended up with a corrupt file on the iPod of about forty five minutes of our second set. After a minute or two of searching I discovered that Audacity has a file menu option called “Import Raw”. Using this option I was able to import the unreadable content into Audacity.

I was delighted to see that most of the recording was intact. However, what was was interesting to me is that at the end of the file was about a minute or more of random white noise. I fancifully imagined this as my iPod going into a dream state as the power level was no longer adequate to support the standard functionality of the device. So here’s the first 48 milliseconds of that dream state with a three dB pad to eliminate clipping.

Ghost in the Machine

Insectoid X-19

This afternoon I stumbled upon another one of my recent FM synthesis experiments from November 2, 2008. On that day I recorded eight minutes of output from select randomized programs that I produced using a MaxMSP patch called X.FM. You can hear all of the examples I have posted so far by clicking on the FM Synthesis topic.

This eighth example in the series has some nice rhythmic, pulsating characteristics to it. I edited the sound out from the surrounding audio, then exported it with normalization to boost the levels.

Insectoid X-19

Portable Digital Recorder Resources

After several weeks of research I have finally made a decision and purchased a Sony PCM-D50 digital recorder (without the fancy leather carrying case) to replace my mostly broken Sony PCM-M1 portable DAT.

During my research I came across some excellent resources that helped me make up my mind. I found some of the most thorough information on O’Reilly Digital Media. Their comparison chart was invaluable along with the extensive reviews of all the devices listed there. I consulted other in-depth reviews and another great comparison chart at Transom.org. I also read many of Brad Linder’s reviews including his review of the PCM-D50 and Create Digital Music pointed me to more reviews of just about everything I looked into.

This is by no means a complete list. I read lots of other articles and websites along the way, but these sites certainly helped the process along. I have yet to receive my new toy, but as soon as I do I’ll be posting some first impressions and sample recordings.

Mangled, Reversed, Distant and Filtered Piano

Over processing usually leaves you with audio that lacks it original luster, or perhaps it starts to sound like the processor itself. However, sometimes you might end up with something interesting as a result of pushing the processing beyond the normal boundaries. While listening to the garbled piano in the last entry I could hear something haunting about the passage, so I decided that I would try to bring out those haunting characteristics by adding some unrestrained processing to the recording. I started by reversing it and pitching it down a couple of semitones. This brought out a brief harmonic minor minor melody. Later, after applying some extreme filtering and massive reverb I ended up with this thin, distant, and haunting sequence.

Mangled, Reversed, Distant, and Filtered Piano

iPod Garbled Piano Recording

I finally made a dock connector for my third generation iPod that I’ve been making experimental recordings on with Linux and an AT822 stereo mic. Prior to making the dock connector I was only able to make mono recordings via the headphone jack. Since the dock connector only accepts a line level signal, I am pre-amping the AT822 with my ailing Sony PCM-M1 DAT recorder (it eats tapes, so it’s a useful retirement).

With this setup I am able to use the otherwise useless DAT recorder by connecting the stereo mic to the mic input, putting the device in record mode, adjusting the levels, and then taking the line out to the dock connector on the iPod as shown in the photograph. The recordings are relatively clean except for a tiny bit of high frequency interference that I haven’t tracked down yet.

The only other problem is that recording in stereo seems to tax the resources of the iPod. When I try to record at a sampling rate higher than 44.1kHz the audio is likely to suffer from a bizarre digital jitter effect. Here’s an example of a piano recording at 88kHz that I played and edited together to illustrate the jitter problem. I wouldn’t use this rate for anything I want to record well, but I kind of like the stuttering sound it creates as the iPod fails to process the audio quickly enough to store it accurately.

iPod Garbled Piano Recording

There’s Four Chips in that Bag

I top and tailed this clip of ambiance from a popular lunch spot in downtown Minneapolis, applying quick fades in the beginning and end of the twenty four second example. I also applied normalization to boost the levels.

One of the employees prompts a customer into ordering his peperoni sandwich. After that I examine a bag of chips and my friend Derrin advises me that “there’s four chips in that bag”.

Four Chips in that Bag

Old Amplifier Abuse

A couple of weeks ago, while working in the studio with Nils Westdal, we decided to experiment with an old amplifier that has a built in spring reverb. We plugged the direct out into a firewire interface and hit the record button in the software. Nothing was plugged into the amp, but by turning up the reverb knob all the way and the volume most of the way up, the spring reverb became very sensitive to vibrations. All that was left to do was to bang the amp around a bit while capturing the output.

Spring Reverb

One Hundred Sounds in Eight Seconds

Last Friday, November 7th, to mark my one hundredth sound posted in the One Sound Every Day category, I sequenced forty two equally sized micro samples extracted from sounds I had posted here on AudioCookbook.org. Due to a trip scheduled out of the country, I ran out of time and did not compile all of the available ninety nine sounds into the piece. As promised in the original post, I have now managed to complete the chronologically sequenced compilation of micro samples into eight seconds of chaotic noise. I extended the one hundredth sample of Caribbean surf as an ending to the staccato sequence.

100 Micro Samples

The Sounds of Failing Hard Drives

Slashdot.org has an article about a site that is hosting the sounds of thirty five different hard drives failing. Although the recording quality is generally poor there are some really interesting sounds including a Maxtor drive with a stuck spindle producing a “futuristic cell phone melody”. You can read the article and checkout the sounds here, although it might be a bit busy due to the site being slashdotted.

Also, click the image to see a video of a remix of Nude by Radiohead made entirely out of sounds captured from old computer peripherals including a dot matrix printer, scanner, cassette drive, hard drives, and so on. The remix and video was created by Glasgow based artist James Houston.

Caribbean Surf and Tide Pools

I recently recorded the sound of Caribbean surf and the gurgling of the waves as they receded from tide pools on a beach near Playa del Carmen in Quintana Roo, Mexico. I did my best to shield the wind from the mic, but the cheap foam wind screen I brought with me was painfully inadequate.

To try and repair the sound I edited a few instances of clipping, and ran the lot through a a high pass filter to reduce some of the wind noise. Finally I compressed the audio to bring out some of the gurgling and splashy sounds.

Caribbean Surf

Warped Space Flute

This sound is the seventh entry in my series of FM synthesis experiments. There are some very strange high frequency overtones audible in the first half of the sound. If you can bear the high frequencies, I suggest looping this sound and then listening to it for about thirty minutes.

As you listen say to yourself, “I will stop smoking cigarettes. I will stop smoking cigarettes.” If you are a non-smoker afterward and were not a non-smoker before, let me know and we’ll start a business.

Warped Space Flute

Subterranean Sonar

Number six in my series of FM synthesis experiments is a grainy, low frequency stomach growl that makes me imagine subterranean seismic activity. For this example I played a randomized patch three times at different positions on the keyboard while exploring the patch.

One word of warning: I have not filtered out any subsonic frequencies or tested the audio on equipment that is capable of producing them.

Subterranian Sonar

Spontaneous Polymerization

Number five in my sequence of experiments with FM synthesis is a bit noisier than the previous entries which is typical of sounds produced by randomizing parameters. Most of these I leave by the wayside, or edit specific parameters to make them more usable. However, this sound endeared me with is dirty and gravely characteristics. It caused me to imagine some scientific device of the future capable of materializing products or replicating a potato in a manner of seconds. This is the sound of that hypothetical device.

Spontaneous Polymerization