Gallery: describe the shape sweeps from the rendered metrics
2 changed files+16−16
docs/gallery/index.htmlmodified+8−8View file
@@ -942,7 +942,7 @@ svg.setup { display: block; max-width: 100%; height: auto; }
942942 </section>
943943 <section id="outline">
944944 <h2>Sheet: outline at equal area (push and release)</h2>
945-<p>Four outlines cut from the same amount of steel (216 square inches, the area of the default 12 by 18 inch sheet): the rectangle, a square, the ellipse of the same 2:3 proportions, and a circle. Everything else is held at the defaults, including the 3 mm bow across the width. The push acts at a corner for the rectangle and the square and at the rim point opposite the hole for the ellipse and the circle, so part of the difference is the excitation itself: a rim point of an ellipse is stiffer than the corner of a rectangle, and the same 10 mm push deforms the whole sheet rather than bending a corner.</p>
945+<p>Four outlines cut from the same amount of steel (216 square inches, the area of the default 12 by 18 inch sheet): the rectangle, a square, the ellipse of the same 2:3 proportions, and a circle. Everything else stays at the defaults, including the 3 mm bow across the width. The push acts at a corner for the rectangle and the square and at the rim point opposite the hole for the ellipse and the circle, and this changes the excitation as much as the outline changes the modes: the rim of an ellipse is stiffer than the corner of a rectangle, so the same 10 mm push deforms the whole sheet instead of bending a corner, stores more energy, and makes the ellipse and the circle about 10 dB louder than the rectangle and the square. The square is lower and purer than the rectangle, with about 8 dB less between 500 Hz and 2 kHz; the circle is the purest of the four, and the ellipse keeps the most energy above 2 kHz.</p>
946946 <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>
947947 <div class="cards"><div class="card">
948948 <div class="label">rectangle 12 x 18 in</div>
@@ -1003,7 +1003,7 @@ svg.setup { display: block; max-width: 100%; height: auto; }
10031003 </section>
10041004 <section id="outline-strike">
10051005 <h2>Sheet: outline at equal area (drumstick strike)</h2>
1006-<p>The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the push. The strike point is at the same fraction of the width and height in every case.</p>
1006+<p>The same four outlines excited by the default drumstick strike (30 g at 3 m/s), at the same fraction of the width and height in every case. With the excitation now the same, the peak levels agree to within half a decibel and the differences are in the timbre: the rectangle is the brightest (centroid about 650 Hz), the circle by far the darkest (about 280 Hz) with a strong low band, and the square and the ellipse lie in between. The square and the circle also put more energy below 100 Hz than the two elongated shapes.</p>
10071007 <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>
10081008 <div class="cards"><div class="card">
10091009 <div class="label">rectangle 12 x 18 in</div>
@@ -1064,7 +1064,7 @@ svg.setup { display: block; max-width: 100%; height: auto; }
10641064 </section>
10651065 <section id="ellipse-size">
10661066 <h2>Ellipse: size (push and release)</h2>
1067-<p>Elliptical sheets inscribed in the same bounding boxes as the rectangular size sweep above, pushed 10 mm at the rim.</p>
1067+<p>Elliptical sheets inscribed in the same bounding boxes as the rectangular size sweep above, pushed 10 mm at the rim. Unlike the rectangles, which get quieter as they grow, the ellipses get louder with size up to 18 by 24 inches, because the rim push loads the whole sheet. The 12 by 18 inch ellipse is much the brightest of the set, with a centroid above 500 Hz; the larger ellipses are lower and purer, and the 24 by 36 inch sheet again puts most of its energy below 100 Hz, where its lowest modes are barely audible.</p>
10681068 <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>
10691069 <div class="cards"><div class="card">
10701070 <div class="label">8 x 12 in</div>
@@ -1125,7 +1125,7 @@ svg.setup { display: block; max-width: 100%; height: auto; }
11251125 </section>
11261126 <section id="ellipse-size-strike">
11271127 <h2>Ellipse: size (drumstick strike)</h2>
1128-<p>The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the push.</p>
1128+<p>The same sweep excited by the default drumstick strike (30 g at 3 m/s). The trend matches the rectangles: larger ellipses are louder and lower, the 18 by 24 inch sheet reaching about 104 dB at its peak against 100 dB for the smallest, while the centroid falls from about 750 Hz at 12 by 18 inches to about 300 Hz at 24 by 36 inches.</p>
11291129 <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>
11301130 <div class="cards"><div class="card">
11311131 <div class="label">8 x 12 in</div>
@@ -1186,7 +1186,7 @@ svg.setup { display: block; max-width: 100%; height: auto; }
11861186 </section>
11871187 <section id="ellipse-bow-amplitude">
11881188 <h2>Ellipse: initial bow (push and release)</h2>
1189-<p>The 12 by 18 inch ellipse with a flat shape and with bows of 1.5, 3 and 6 mm across the width, pushed 10 mm at the rim.</p>
1189+<p>The 12 by 18 inch ellipse with a flat shape and with bows of 1.5, 3 and 6 mm across the width, pushed 10 mm at the rim. The bow matters more for the ellipse than for the rectangle: the peak level rises by about 15 dB from the flat plate to the 6 mm bow (9 dB for the rectangle), and the sound turns from a low, pure ring into a bright one, with the energy above 2 kHz rising by about 30 dB between 1.5 and 6 mm.</p>
11901190 <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>
11911191 <div class="cards"><div class="card">
11921192 <div class="label">0 mm</div>
@@ -1247,7 +1247,7 @@ svg.setup { display: block; max-width: 100%; height: auto; }
12471247 </section>
12481248 <section id="ellipse-bow-amplitude-strike">
12491249 <h2>Ellipse: initial bow (drumstick strike)</h2>
1250-<p>The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the push.</p>
1250+<p>The same sweep excited by the default drumstick strike (30 g at 3 m/s). As for the rectangle, the trend reverses under the strike: the flat ellipse rings brightest (centroid above 900 Hz) and the 6 mm bow gives the dullest sound, about 10 dB weaker above 2 kHz, while the peak pressure is the same in all four clips.</p>
12511251 <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>
12521252 <div class="cards"><div class="card">
12531253 <div class="label">0 mm</div>
@@ -1308,7 +1308,7 @@ svg.setup { display: block; max-width: 100%; height: auto; }
13081308 </section>
13091309 <section id="ellipse-bow-shape">
13101310 <h2>Ellipse: shape of the bow (push and release)</h2>
1311-<p>The same 3 mm sag on the 12 by 18 inch ellipse as a bow across the width, across the height, or as a dish curved both ways.</p>
1311+<p>The same 3 mm sag on the 12 by 18 inch ellipse as a bow across the width, across the height, or as a dish curved both ways. The bow across the width gives the loudest and brightest sound; the bow across the height is about 5 dB quieter and much purer, with almost nothing above 2 kHz; the dish is as loud as the width bow but less bright.</p>
13121312 <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>
13131313 <div class="cards"><div class="card">
13141314 <div class="label">across the width</div>
@@ -1355,7 +1355,7 @@ svg.setup { display: block; max-width: 100%; height: auto; }
13551355 </section>
13561356 <section id="ellipse-bow-shape-strike">
13571357 <h2>Ellipse: shape of the bow (drumstick strike)</h2>
1358-<p>The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the push.</p>
1358+<p>The same sweep excited by the default drumstick strike (30 g at 3 m/s). The peak is the same for all three; the width bow is the brightest (centroid about 750 Hz against 500 Hz for the other two), and the dish puts the most energy below 100 Hz.</p>
13591359 <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>
13601360 <div class="cards"><div class="card">
13611361 <div class="label">across the width</div>
docs/gallery/manifest.jsonmodified+8−8View file
@@ -323,7 +323,7 @@
323323 {
324324 "id": "outline",
325325 "title": "Sheet: outline at equal area (push and release)",
326- "text": "Four outlines cut from the same amount of steel (216 square inches, the area of the default 12 by 18 inch sheet): the rectangle, a square, the ellipse of the same 2:3 proportions, and a circle. Everything else is held at the defaults, including the 3 mm bow across the width. The push acts at a corner for the rectangle and the square and at the rim point opposite the hole for the ellipse and the circle, so part of the difference is the excitation itself: a rim point of an ellipse is stiffer than the corner of a rectangle, and the same 10 mm push deforms the whole sheet rather than bending a corner.",
326+ "text": "Four outlines cut from the same amount of steel (216 square inches, the area of the default 12 by 18 inch sheet): the rectangle, a square, the ellipse of the same 2:3 proportions, and a circle. Everything else stays at the defaults, including the 3 mm bow across the width. The push acts at a corner for the rectangle and the square and at the rim point opposite the hole for the ellipse and the circle, and this changes the excitation as much as the outline changes the modes: the rim of an ellipse is stiffer than the corner of a rectangle, so the same 10 mm push deforms the whole sheet instead of bending a corner, stores more energy, and makes the ellipse and the circle about 10 dB louder than the rectangle and the square. The square is lower and purer than the rectangle, with about 8 dB less between 500 Hz and 2 kHz; the circle is the purest of the four, and the ellipse keeps the most energy above 2 kHz.",
327327 "clips": [
328328 {
329329 "label": "rectangle 12 x 18 in",
@@ -357,7 +357,7 @@
357357 {
358358 "id": "outline-strike",
359359 "title": "Sheet: outline at equal area (drumstick strike)",
360- "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the push. The strike point is at the same fraction of the width and height in every case.",
360+ "text": "The same four outlines excited by the default drumstick strike (30 g at 3 m/s), at the same fraction of the width and height in every case. With the excitation now the same, the peak levels agree to within half a decibel and the differences are in the timbre: the rectangle is the brightest (centroid about 650 Hz), the circle by far the darkest (about 280 Hz) with a strong low band, and the square and the ellipse lie in between. The square and the circle also put more energy below 100 Hz than the two elongated shapes.",
361361 "base": {
362362 "excitation": "strike"
363363 },
@@ -394,7 +394,7 @@
394394 {
395395 "id": "ellipse-size",
396396 "title": "Ellipse: size (push and release)",
397- "text": "Elliptical sheets inscribed in the same bounding boxes as the rectangular size sweep above, pushed 10 mm at the rim.",
397+ "text": "Elliptical sheets inscribed in the same bounding boxes as the rectangular size sweep above, pushed 10 mm at the rim. Unlike the rectangles, which get quieter as they grow, the ellipses get louder with size up to 18 by 24 inches, because the rim push loads the whole sheet. The 12 by 18 inch ellipse is much the brightest of the set, with a centroid above 500 Hz; the larger ellipses are lower and purer, and the 24 by 36 inch sheet again puts most of its energy below 100 Hz, where its lowest modes are barely audible.",
398398 "base": {
399399 "shape": "ellipse"
400400 },
@@ -429,7 +429,7 @@
429429 {
430430 "id": "ellipse-size-strike",
431431 "title": "Ellipse: size (drumstick strike)",
432- "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the push.",
432+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s). The trend matches the rectangles: larger ellipses are louder and lower, the 18 by 24 inch sheet reaching about 104 dB at its peak against 100 dB for the smallest, while the centroid falls from about 750 Hz at 12 by 18 inches to about 300 Hz at 24 by 36 inches.",
433433 "base": {
434434 "shape": "ellipse",
435435 "excitation": "strike"
@@ -465,7 +465,7 @@
465465 {
466466 "id": "ellipse-bow-amplitude",
467467 "title": "Ellipse: initial bow (push and release)",
468- "text": "The 12 by 18 inch ellipse with a flat shape and with bows of 1.5, 3 and 6 mm across the width, pushed 10 mm at the rim.",
468+ "text": "The 12 by 18 inch ellipse with a flat shape and with bows of 1.5, 3 and 6 mm across the width, pushed 10 mm at the rim. The bow matters more for the ellipse than for the rectangle: the peak level rises by about 15 dB from the flat plate to the 6 mm bow (9 dB for the rectangle), and the sound turns from a low, pure ring into a bright one, with the energy above 2 kHz rising by about 30 dB between 1.5 and 6 mm.",
469469 "param": "bowAmplitude",
470470 "unit": "mm",
471471 "scale": 0.001,
@@ -482,7 +482,7 @@
482482 {
483483 "id": "ellipse-bow-amplitude-strike",
484484 "title": "Ellipse: initial bow (drumstick strike)",
485- "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the push.",
485+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s). As for the rectangle, the trend reverses under the strike: the flat ellipse rings brightest (centroid above 900 Hz) and the 6 mm bow gives the dullest sound, about 10 dB weaker above 2 kHz, while the peak pressure is the same in all four clips.",
486486 "param": "bowAmplitude",
487487 "unit": "mm",
488488 "scale": 0.001,
@@ -500,7 +500,7 @@
500500 {
501501 "id": "ellipse-bow-shape",
502502 "title": "Ellipse: shape of the bow (push and release)",
503- "text": "The same 3 mm sag on the 12 by 18 inch ellipse as a bow across the width, across the height, or as a dish curved both ways.",
503+ "text": "The same 3 mm sag on the 12 by 18 inch ellipse as a bow across the width, across the height, or as a dish curved both ways. The bow across the width gives the loudest and brightest sound; the bow across the height is about 5 dB quieter and much purer, with almost nothing above 2 kHz; the dish is as loud as the width bow but less bright.",
504504 "base": {
505505 "shape": "ellipse"
506506 },
@@ -528,7 +528,7 @@
528528 {
529529 "id": "ellipse-bow-shape-strike",
530530 "title": "Ellipse: shape of the bow (drumstick strike)",
531- "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the push.",
531+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s). The peak is the same for all three; the width bow is the brightest (centroid about 750 Hz against 500 Hz for the other two), and the dish puts the most energy below 100 Hz.",
532532 "base": {
533533 "shape": "ellipse",
534534 "excitation": "strike"