Edϕ: Difference between revisions

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m Cmloegcmluin moved page 7edφ to Edφ: learned more about this domain since when I first started writing this page this morning
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Various equal divisions of the octave have close approximations of acoustic phi, or <span><math>φ</math></span>, ≈833.090296357¢.
 
Various equal divisions of the octave have close approximations of acoustic phi, or , ≈833.090296357¢. <span><math>φ</math></span>If the <span><math>m^{th}</math></span> step of <span><math>n</math><span>ed2 is a close approximation of <span><math>φ</math></span>, the <span><math>n^{th}</math></span> step of <span><math>m</math><span>ed<span><math>φ</math></span> will be a close approximation of 2.
If the <span><math>m^{th}</math></span> step of <span><math>n</math><span>ed2 is a close approximation of <span><math>φ</math></span>, the <span><math>n^{th}</math></span> step of <span><math>m</math><span>ed<span><math>φ</math></span> will be a close approximation of 2.


For example, the 7th step of 10ed2 is 840¢, and the 10th step of 7ed<span><math>φ</math></span> is ≈1190.128995¢.  
For example, the 7th step of 10ed2 is 840¢, and the 10th step of 7ed<span><math>φ</math></span> is ≈1190.128995¢.  
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{| class="wikitable"
{| class="wikitable"
|+
|+
|
| rowspan="2" |'''scale step'''
| colspan="4" |'''10ed2'''
| colspan="4" |'''10ed2'''
| colspan="4" |'''7edφ or 10ed(<math>2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015</math>)'''
| colspan="4" |'''7edφ or 10ed(<math>2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015</math>)'''
|-
|-
|'''scale step'''
|'''frequency multiplier (definition)'''
|'''frequency multiplier (definition)'''
|'''10ed2 frequency multiplier (decimal)'''
|'''10ed2 frequency multiplier (decimal)'''
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|1190.128995
|1190.128995
|119.0128995
|119.0128995
|}
{| class="wikitable"
|+
| rowspan="2" |'''scale step'''
| colspan="4" |'''13ed2'''
| colspan="4" |'''9edφ or 13ed(<math>2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015</math>)<math>2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015</math>'''
|-
|'''frequency multiplier (definition)'''
|'''10ed2 frequency multiplier (decimal)'''
|'''pitch (¢)'''
|'''Δ (¢)'''
|'''frequency multiplier (definition)'''
|'''frequency multiplier (decimal)'''
|'''pitch (¢)'''
|'''Δ (¢)'''
|-
|'''1'''
|
|1.054766076
|92.30769231
|92.30769231
|
|1.054923213
|92.56558848
|92.56558848
|-
|'''2'''
|
|1.112531476
|184.6153846
|92.30769231
|
|1.112862986
|185.131177
|92.56558848
|-
|'''3'''
|
|1.17346046
|276.9230769
|92.30769231
|
|1.173984997
|277.6967655
|92.56558848
|-
|'''4'''
|
|1.237726285
|369.2307692
|92.30769231
|
|1.238464025
|370.2623539
|92.56558848
|-
|'''5'''
|
|1.305511698
|461.5384615
|92.30769231
|
|1.306484449
|462.8279424
|92.56558848
|-
|'''6'''
|
|1.377009451
|553.8461538
|92.30769231
|
|1.378240772
|555.3935309
|92.56558848
|-
|'''7'''
|
|1.452422856
|646.1538462
|92.30769231
|
|1.453938184
|647.9591194
|92.56558848
|-
|'''8'''
|
|1.531966357
|738.4615385
|92.30769231
|
|1.533793141
|740.5247079
|92.56558848
|-
|'''9'''
|
|1.615866144
|830.7692308
|92.30769231
|
|1.618033989
|833.0902964
|92.56558848
|-
|'''10'''
|
|1.704360793
|923.0769231
|92.30769231
|
|1.706901614
|925.6558848
|92.56558848
|-
|11
|
|1.797701946
|1015.384615
|92.30769231
|
|1.800650136
|1018.221473
|92.56558848
|-
|12
|
|1.896155029
|1107.692308
|92.30769231
|
|1.899547627
|1110.787062
|92.56558848
|-
|13
|
|2
|1200
|92.30769231
|
|2.003876886
|1203.35265
|92.56558848
|}
|}

Revision as of 00:07, 9 February 2020

Various equal divisions of the octave have close approximations of acoustic phi, or , ≈833.090296357¢. [math]\displaystyle{ φ }[/math]If the [math]\displaystyle{ m^{th} }[/math] step of [math]\displaystyle{ n }[/math]ed2 is a close approximation of [math]\displaystyle{ φ }[/math], the [math]\displaystyle{ n^{th} }[/math] step of [math]\displaystyle{ m }[/math]ed[math]\displaystyle{ φ }[/math] will be a close approximation of 2.

For example, the 7th step of 10ed2 is 840¢, and the 10th step of 7ed[math]\displaystyle{ φ }[/math] is ≈1190.128995¢. As another example, the 9th step of 13ed2 is ≈830.7692308¢, and the 13th step of 9ed[math]\displaystyle{ φ }[/math] is ≈1203.35265¢.

Such [math]\displaystyle{ m }[/math]ed[math]\displaystyle{ φ }[/math] are interesting as variants of their respective [math]\displaystyle{ n }[/math]ed[math]\displaystyle{ 2 }[/math], introducing some combination tone powers.

scale step 10ed2 7edφ or 10ed([math]\displaystyle{ 2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015 }[/math])
frequency multiplier (definition) 10ed2 frequency multiplier (decimal) pitch (¢) Δ (¢) frequency multiplier (definition) frequency multiplier (decimal) pitch (¢) Δ (¢)
1 [math]\displaystyle{ 2^{\frac{1}{10}} }[/math] 1.071773463 120 120 [math]\displaystyle{ φ^{\frac{1}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{1}{10}} }[/math] 1.071162542 119.0128995 119.0128995
2 [math]\displaystyle{ 2^{\frac{2}{10}} }[/math] 1.148698355 240 120 [math]\displaystyle{ φ^{\frac{2}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{2}{10}} }[/math] 1.147389191 238.025799 119.0128995
3 [math]\displaystyle{ 2^{\frac{3}{10}} }[/math] 1.231144413 360 120 [math]\displaystyle{ φ^{\frac{3}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{3}{10}} }[/math] 1.229040323 357.0386984 119.0128995
4 [math]\displaystyle{ 2^{\frac{4}{10}} }[/math] 1.319507911 480 120 [math]\displaystyle{ φ^{\frac{4}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{4}{10}} }[/math] 1.316501956 476.0515979 119.0128995
5 [math]\displaystyle{ 2^{\frac{5}{10}} }[/math] 1.414213562 600 120 [math]\displaystyle{ φ^{\frac{5}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{5}{10}} }[/math] 1.410187582 595.0644974 119.0128995
6 [math]\displaystyle{ 2^{\frac{6}{10}} }[/math] 1.515716567 720 120 [math]\displaystyle{ φ^{\frac{6}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{6}{10}} }[/math] 1.510540115 714.0773969 119.0128995
7 [math]\displaystyle{ 2^{\frac{7}{10}} }[/math] 1.624504793 840 120 [math]\displaystyle{ φ^{\frac{7}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{7}{10}} }[/math] 1.618033989 833.0902964 119.0128995
8 [math]\displaystyle{ 2^{\frac{8}{10}} }[/math] 1.741101127 960 120 [math]\displaystyle{ φ^{\frac{8}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{8}{10}} }[/math] 1.7331774 952.1031958 119.0128995
9 [math]\displaystyle{ 2^{\frac{9}{10}} }[/math] 1.866065983 1080 120 [math]\displaystyle{ φ^{\frac{9}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{9}{10}} }[/math] 1.85651471 1071.116095 119.0128995
10 [math]\displaystyle{ 2^{\frac{10}{10}} }[/math] 2 1200 120 [math]\displaystyle{ φ^{\frac{10}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{10}{10}} }[/math] 1.988629015 1190.128995 119.0128995
scale step 13ed2 9edφ or 13ed([math]\displaystyle{ 2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015 }[/math])[math]\displaystyle{ 2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015 }[/math]
frequency multiplier (definition) 10ed2 frequency multiplier (decimal) pitch (¢) Δ (¢) frequency multiplier (definition) frequency multiplier (decimal) pitch (¢) Δ (¢)
1 1.054766076 92.30769231 92.30769231 1.054923213 92.56558848 92.56558848
2 1.112531476 184.6153846 92.30769231 1.112862986 185.131177 92.56558848
3 1.17346046 276.9230769 92.30769231 1.173984997 277.6967655 92.56558848
4 1.237726285 369.2307692 92.30769231 1.238464025 370.2623539 92.56558848
5 1.305511698 461.5384615 92.30769231 1.306484449 462.8279424 92.56558848
6 1.377009451 553.8461538 92.30769231 1.378240772 555.3935309 92.56558848
7 1.452422856 646.1538462 92.30769231 1.453938184 647.9591194 92.56558848
8 1.531966357 738.4615385 92.30769231 1.533793141 740.5247079 92.56558848
9 1.615866144 830.7692308 92.30769231 1.618033989 833.0902964 92.56558848
10 1.704360793 923.0769231 92.30769231 1.706901614 925.6558848 92.56558848
11 1.797701946 1015.384615 92.30769231 1.800650136 1018.221473 92.56558848
12 1.896155029 1107.692308 92.30769231 1.899547627 1110.787062 92.56558848
13 2 1200 92.30769231 2.003876886 1203.35265 92.56558848