Recreating The THX Deep Note

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Few sounds are as recognizable as the THX Deep Note. [Batuhan] did some research, and set about recreating the sound. The original Deep Note (mp3 link) was created in 1982 by [Dr. James A. Moorer]. [Dr. Moorer] used the Audio Signal Processor (ASP) (AKA SoundDroid) to create the sound. The ASP was a complex machine to program. The Deep Note took about 20,000 lines of C code to program. The C code was compiled to about 250,000 discrete statements to command the ASP.

Only one ASP was ever built, and LucasFilm owned it. Instead of recreating the hardware, [Batuhan] used SuperCollider to recreate the sound. Just like the ASP, SuperCollider is a tool for real-time audio synthesis. The difference is that SuperCollider is open source and runs on modern computers. [Batuhan] used his research and ears to perform an analysis of the Deep Note. He created two re-creations. The first is carefully constructed to replicate the sound. The second is a Twitter worthy 140 character version. Both versions are reasonable facsimiles of the original Deep Note, though they’re not quite perfect to our ears.

[Batuhan] isn’t the only person working on recreations. Deep Note in 1KB of JavaScript can be heard at We’d love to hear other versions created by Hackaday readers!

[Via Reddit]

28 thoughts on “Recreating The THX Deep Note

  1. My dad had a rackmount Peavey module that would do it but he lost the patch after archiving across a system dump across a midi line. I think he overwrote a floppy that had the patch.

  2. I find it really hard to believe it took 20,000 lines of C code to originally generate this sound. Maybe if you’re including standard C libraries in your line count. Or exaggerating. Or getting paid by the hour by someone with deep pockets.

    1. I thought so, too. But read this (

      The score consists of a C program of about 20,000 lines of code. The output of this program is not the sound itself, but is the sequence of parameters that drives the oscillators on the Audio Signal Processor (ASP). That 20,000 lines of code produce about 250,000 lines of statements of the form “set frequency of oscillator X to Y Hertz”

      So maybe that makes sense? And maybe (as you implied) they made it longer than necessary; unrolled loops, etc.?

    1. That is exactly Deep Note at the end of that track, 12 years before Lucasfilm did theirs. But who has the money and the lawyers, eh?

      Same kind of deal with Jane Yolen’s “Wizard Hall”, written a decade before J.K. Rowling’s “Philosopher’s Stone”, but who has the big money and the lawyers…

        1. “The Worst Witch” has been running on TV for years before any Harry Potter books came out. It’s the same thing, only with girls at witch school. There’s probably versions older then the Bible. “Young Nebuchadnezzar goes to God school”.

  3. How Risset tones rising and falling ending on a octave chord get called “deep note” is beyond me. I was expecting the black note, darker than the brown one.
    One could program an analogue synth to make this sequence, easier to do in reverse. Just don’t use 30 VCO’s. I just set my guitar to multi-delay and run it into the DL-4 and use the reverse mode and let a big slide down to the nut.

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