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3<title>Steel sheet gong: how the parameters shape the sound</title>
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15<h1>Steel sheet gong: how the parameters shape the sound</h1>
16<p>Each section varies one property of the simulated sheet or of the excitation while everything else stays at the simulator defaults: a 12 by 18 inch, 22 gauge (0.79 mm) stainless steel sheet hanging in portrait orientation with a 3 mm bow across its width, heard 1 m in front of its center, recorded for 4 s. The clips are computed with the simulator's default numerical settings (8 mm grid), so the 'Open in simulator' links reproduce them exactly. Click a player to hear a clip. Every clip is rendered at the simulator's default playback level (+20 dB relative to 1 Pa at full scale, with the same soft clipper), so loudness differences within and between sections are the ones the model predicts, and a clip sounds as it does in the app. The numbers under each clip are the peak pressure and sound pressure level at the listener, the RMS pressure over the clip, the spectral centroid of the sound between 0.2 and 1.2 s (a measure of brightness), and fitted 60 dB decay times of a low and a high band.</p>
17<ul class="toc"><li><a href="#strike-speed">Drumstick: stick speed</a></li><li><a href="#strike-mass">Drumstick: stick mass</a></li><li><a href="#strike-stiffness">Drumstick: tip hardness</a></li></ul>
18<section id="strike-speed">
19<h2>Drumstick: stick speed</h2>
20<p>A wooden stick tip (30 g effective mass) strikes the sheet at 70 percent of its width and 35 percent of its height. Speed sets both the loudness and the character: the contact force grows with speed, the contact shortens, and more energy reaches the high modes. The sound grows brighter as well as louder.</p>
21<p class="dim">Playback gain +20 dB relative to 1 Pa = 0 dBFS (the simulator's default is +20 dB); loud onsets are soft-clipped. Spectrograms: 0 to 5 kHz over the clip, 80 dB range, one color scale per section.</p>
22<div class="cards"><div class="card">
23 <div class="label">0.5 m/s</div>
24 <audio controls preload="none" src="clips/strike-speed-0.wav"></audio>
25 <img src="clips/strike-speed-0.png" alt="spectrogram" width="640" height="200">
26 <div class="metrics">
27 <div>peak 0.435 Pa (87 dB SPL)</div>
28 <div>RMS 1.7 mPa</div>
29 <div>centroid 192 Hz</div>
30 <div>T60 100-500 Hz 4.8 s, 2-8 kHz 8.6 s</div>
31 <div>contact force 28 N</div>
32 <div class="dim">wav peak 12.8 dBFS (soft-clipped)</div>
33 </div>
34 <a href="../../?excitation=strike&strikeVelocity=0.5">Open in simulator</a>
35</div>
36<div class="card">
37 <div class="label">1 m/s</div>
38 <audio controls preload="none" src="clips/strike-speed-1.wav"></audio>
39 <img src="clips/strike-speed-1.png" alt="spectrogram" width="640" height="200">
40 <div class="metrics">
41 <div>peak 0.891 Pa (93 dB SPL)</div>
42 <div>RMS 3.6 mPa</div>
43 <div>centroid 259 Hz</div>
44 <div>T60 100-500 Hz 4.8 s, 2-8 kHz 6.8 s</div>
45 <div>contact force 58 N</div>
46 <div class="dim">wav peak 19.0 dBFS (soft-clipped)</div>
47 </div>
48 <a href="../../?excitation=strike&strikeVelocity=1">Open in simulator</a>
49</div>
50<div class="card">
51 <div class="label">2 m/s</div>
52 <audio controls preload="none" src="clips/strike-speed-2.wav"></audio>
53 <img src="clips/strike-speed-2.png" alt="spectrogram" width="640" height="200">
54 <div class="metrics">
55 <div>peak 1.676 Pa (98 dB SPL)</div>
56 <div>RMS 7.3 mPa</div>
57 <div>centroid 317 Hz</div>
58 <div>T60 100-500 Hz 3.9 s, 2-8 kHz 5.1 s</div>
59 <div>contact force 124 N</div>
60 <div class="dim">wav peak 24.5 dBFS (soft-clipped)</div>
61 </div>
62 <a href="../../?excitation=strike&strikeVelocity=2">Open in simulator</a>
63</div>
64<div class="card">
65 <div class="label">3 m/s</div>
66 <audio controls preload="none" src="clips/strike-speed-3.wav"></audio>
67 <img src="clips/strike-speed-3.png" alt="spectrogram" width="640" height="200">
68 <div class="metrics">
69 <div>peak 2.552 Pa (102 dB SPL)</div>
70 <div>RMS 10.9 mPa</div>
71 <div>centroid 655 Hz</div>
72 <div>T60 100-500 Hz 4.2 s, 2-8 kHz 4.6 s</div>
73 <div>contact force 195 N</div>
74 <div class="dim">wav peak 28.1 dBFS (soft-clipped)</div>
75 </div>
76 <a href="../../?excitation=strike&strikeVelocity=3">Open in simulator</a>
77</div>
78<div class="card">
79 <div class="label">4.5 m/s</div>
80 <audio controls preload="none" src="clips/strike-speed-4.wav"></audio>
81 <img src="clips/strike-speed-4.png" alt="spectrogram" width="640" height="200">
82 <div class="metrics">
83 <div>peak 4.114 Pa (106 dB SPL)</div>
84 <div>RMS 17.2 mPa</div>
85 <div>centroid 678 Hz</div>
86 <div>T60 100-500 Hz 4.4 s, 2-8 kHz 3.8 s</div>
87 <div>contact force 315 N</div>
88 <div class="dim">wav peak 32.3 dBFS (soft-clipped)</div>
89 </div>
90 <a href="../../?excitation=strike&strikeVelocity=4.5">Open in simulator</a>
91</div>
92<div class="card">
93 <div class="label">6 m/s</div>
94 <audio controls preload="none" src="clips/strike-speed-5.wav"></audio>
95 <img src="clips/strike-speed-5.png" alt="spectrogram" width="640" height="200">
96 <div class="metrics">
97 <div>peak 5.721 Pa (109 dB SPL)</div>
98 <div>RMS 24.9 mPa</div>
99 <div>centroid 1654 Hz</div>
100 <div>T60 100-500 Hz 3.9 s, 2-8 kHz 3.4 s</div>
101 <div>contact force 448 N</div>
102 <div class="dim">wav peak 35.1 dBFS (soft-clipped)</div>
103 </div>
104 <a href="../../?excitation=strike&strikeVelocity=6">Open in simulator</a>
105</div></div>
106</section>
107<section id="strike-mass">
108<h2>Drumstick: stick mass</h2>
109<p>The same speed with a lighter or heavier stick. A heavier stick carries more momentum, stays in contact longer, and pushes the sheet further, which favours the low modes; a light stick gives a short, bright tap.</p>
110<p class="dim">Playback gain +20 dB relative to 1 Pa = 0 dBFS (the simulator's default is +20 dB); loud onsets are soft-clipped. Spectrograms: 0 to 5 kHz over the clip, 80 dB range, one color scale per section.</p>
111<div class="cards"><div class="card">
112 <div class="label">10 g</div>
113 <audio controls preload="none" src="clips/strike-mass-0.wav"></audio>
114 <img src="clips/strike-mass-0.png" alt="spectrogram" width="640" height="200">
115 <div class="metrics">
116 <div>peak 2.452 Pa (102 dB SPL)</div>
117 <div>RMS 9.7 mPa</div>
118 <div>centroid 654 Hz</div>
119 <div>T60 100-500 Hz 4.3 s, 2-8 kHz 5.2 s</div>
120 <div>contact force 183 N</div>
121 <div class="dim">wav peak 27.8 dBFS (soft-clipped)</div>
122 </div>
123 <a href="../../?excitation=strike&stickMass=0.01">Open in simulator</a>
124</div>
125<div class="card">
126 <div class="label">30 g</div>
127 <audio controls preload="none" src="clips/strike-mass-1.wav"></audio>
128 <img src="clips/strike-mass-1.png" alt="spectrogram" width="640" height="200">
129 <div class="metrics">
130 <div>peak 2.552 Pa (102 dB SPL)</div>
131 <div>RMS 10.9 mPa</div>
132 <div>centroid 655 Hz</div>
133 <div>T60 100-500 Hz 4.2 s, 2-8 kHz 4.6 s</div>
134 <div>contact force 195 N</div>
135 <div class="dim">wav peak 28.1 dBFS (soft-clipped)</div>
136 </div>
137 <a href="../../?excitation=strike&stickMass=0.03">Open in simulator</a>
138</div>
139<div class="card">
140 <div class="label">60 g</div>
141 <audio controls preload="none" src="clips/strike-mass-2.wav"></audio>
142 <img src="clips/strike-mass-2.png" alt="spectrogram" width="640" height="200">
143 <div class="metrics">
144 <div>peak 2.578 Pa (102 dB SPL)</div>
145 <div>RMS 12.3 mPa</div>
146 <div>centroid 686 Hz</div>
147 <div>T60 100-500 Hz 4.1 s, 2-8 kHz 3.8 s</div>
148 <div>contact force 205 N</div>
149 <div class="dim">wav peak 28.2 dBFS (soft-clipped)</div>
150 </div>
151 <a href="../../?excitation=strike&stickMass=0.06">Open in simulator</a>
152</div>
153<div class="card">
154 <div class="label">120 g</div>
155 <audio controls preload="none" src="clips/strike-mass-3.wav"></audio>
156 <img src="clips/strike-mass-3.png" alt="spectrogram" width="640" height="200">
157 <div class="metrics">
158 <div>peak 2.591 Pa (102 dB SPL)</div>
159 <div>RMS 17.0 mPa</div>
160 <div>centroid 1346 Hz</div>
161 <div>T60 100-500 Hz 3.5 s, 2-8 kHz 3.2 s</div>
162 <div>contact force 232 N</div>
163 <div class="dim">wav peak 28.3 dBFS (soft-clipped)</div>
164 </div>
165 <a href="../../?excitation=strike&stickMass=0.12">Open in simulator</a>
166</div></div>
167</section>
168<section id="strike-stiffness">
169<h2>Drumstick: tip hardness</h2>
170<p>The Hertz contact stiffness K stands for the hardness of the tip: a soft (rubber or felt) tip has a low K and a long, gentle contact that excites mainly the low modes; a hard tip (dense wood, or a metal beater) has a high K and a sharp click.</p>
171<p class="dim">Playback gain +20 dB relative to 1 Pa = 0 dBFS (the simulator's default is +20 dB); loud onsets are soft-clipped. Spectrograms: 0 to 5 kHz over the clip, 80 dB range, one color scale per section.</p>
172<div class="cards"><div class="card">
173 <div class="label">5000000 N/m^1.5</div>
174 <audio controls preload="none" src="clips/strike-stiffness-0.wav"></audio>
175 <img src="clips/strike-stiffness-0.png" alt="spectrogram" width="640" height="200">
176 <div class="metrics">
177 <div>peak 0.380 Pa (86 dB SPL)</div>
178 <div>RMS 5.1 mPa</div>
179 <div>centroid 375 Hz</div>
180 <div>T60 100-500 Hz 4.4 s, 2-8 kHz 4.7 s</div>
181 <div>contact force 113 N</div>
182 <div class="dim">wav peak 11.6 dBFS (soft-clipped)</div>
183 </div>
184 <a href="../../?excitation=strike&contactStiffness=5000000">Open in simulator</a>
185</div>
186<div class="card">
187 <div class="label">50000000 N/m^1.5</div>
188 <audio controls preload="none" src="clips/strike-stiffness-1.wav"></audio>
189 <img src="clips/strike-stiffness-1.png" alt="spectrogram" width="640" height="200">
190 <div class="metrics">
191 <div>peak 1.436 Pa (97 dB SPL)</div>
192 <div>RMS 7.9 mPa</div>
193 <div>centroid 677 Hz</div>
194 <div>T60 100-500 Hz 4.0 s, 2-8 kHz 4.4 s</div>
195 <div>contact force 148 N</div>
196 <div class="dim">wav peak 23.1 dBFS (soft-clipped)</div>
197 </div>
198 <a href="../../?excitation=strike&contactStiffness=50000000">Open in simulator</a>
199</div>
200<div class="card">
201 <div class="label">500000000 N/m^1.5</div>
202 <audio controls preload="none" src="clips/strike-stiffness-2.wav"></audio>
203 <img src="clips/strike-stiffness-2.png" alt="spectrogram" width="640" height="200">
204 <div class="metrics">
205 <div>peak 2.552 Pa (102 dB SPL)</div>
206 <div>RMS 10.9 mPa</div>
207 <div>centroid 655 Hz</div>
208 <div>T60 100-500 Hz 4.2 s, 2-8 kHz 4.6 s</div>
209 <div>contact force 195 N</div>
210 <div class="dim">wav peak 28.1 dBFS (soft-clipped)</div>
211 </div>
212 <a href="../../?excitation=strike&contactStiffness=500000000">Open in simulator</a>
213</div>
214<div class="card">
215 <div class="label">5000000000 N/m^1.5</div>
216 <audio controls preload="none" src="clips/strike-stiffness-3.wav"></audio>
217 <img src="clips/strike-stiffness-3.png" alt="spectrogram" width="640" height="200">
218 <div class="metrics">
219 <div>peak 3.469 Pa (105 dB SPL)</div>
220 <div>RMS 15.5 mPa</div>
221 <div>centroid 563 Hz</div>
222 <div>T60 100-500 Hz 3.8 s, 2-8 kHz 4.5 s</div>
223 <div>contact force 532 N</div>
224 <div class="dim">wav peak 30.8 dBFS (soft-clipped)</div>
225 </div>
226 <a href="../../?excitation=strike&contactStiffness=5000000000">Open in simulator</a>
227</div></div>
228</section>
229<p class="dim">Generated by <code>steelsim gallery</code>; parameters not listed take the simulator defaults.</p>
230</body></html>