thorax1138.ogg

Thorax-1138 is a bass-heavy sweep and chord inspired by THX's "Deep Note". It makes a fine subwoofer audio test, but probably will sound lousy in headphones.
Other homages to "Deep Note" have been made, but none I've heard have yet had sufficient bass.

To be precise, the "deep note" being hit here is D1 (36.7 Hz). I considered going lower, but some of the material I read about "Deep Note" stated that its fundamental was actually an octave higher, at 74Hz.

Deep notes aren't all this sound has, though. Take a look at the spectrum analysis view (included as the cover art in the OGG file) and you'll see that it is lush in harmonics. That's due to two factors: I made it out of square waves only, plus I added chorusing on the final chord.

I created this using a command-line UNIX tool called "SoX". This was done in a single invocation of SoX and could actually be written as a one line script. However, to make this easier for other people to edit, I've split the parts out (see script below). Note that the sound will be slightly different each time it is run as it uses a random number generator.

I hope that other people do take this script and improve upon it. To encourage that, I am releasing the sound and script under more liberal licensing than the Freesound default. You may, at your option, use this script and sound under the Creative Commons Attribution or the GNU General Public License 2.0 (or higher).

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#!/bin/bash -xe
# Just for fun, play some sounds vaguely like the THX "Deep Note" using SoX.

# Length of sweep
sweep=15
# Length of final chord
final=15
# Length to hold chord before fading
hold=1

# Pick 30 random starting frequencies between 200 and 400Hz
for ((i=0; i<30; i++)); do
start[$i]=$((200 + RANDOM%200))
done

# Pick some ending frequencies
for ((i=0; i<10; i++)); do
end[$i]=D2
done
for ((i=10; i<20; i++)); do
end[$i]=D3
done
for ((i=20; i<30; i++)); do
end[$i]=D4
done

wobble() {
# triangular approximation of vibrato using bend, 1Hz
echo "bend 0,100,1" # 100 Actual accumulated bend
echo "0,-180,2" # -80
echo "0,144,2" # 64
echo "0,-115,2" # -51
echo "0,92,2" # 41
echo "0,-73,2" # -32
echo "0,59,2" # 27
echo "0,-27,2" # 0
}

finalchorus() {
echo "chorus 0.5 0.9 50 0.4 0.25 2 -t
60 0.32 0.4 2.3 -t
40 0.3 0.3 1.3 -s"
}

sox --multi-threaded -n -c 2 output.wav synth $sweep $(
for ((i=0; i<30; i++)); do
echo square ${start[$i]}:${end[$i]}
done
) \
$(wobble) \
fade h 5 fade t $sweep \
: synth $final square D1 square D1 square D2 square D3 square D4 \
$(finalchorus) \
fade h 0 $final $((final-hold))

sox output.wav -n rate 6k spectrogram && mimeopen spectrogram.png &
play output.wav

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