Ed12 means Division of the Twelfth Harmonic (12/1) into n equal parts.
Overview
The twelfth harmonic is particularly wide as far as equivalences go. There are (at absolute most) ~3.1 dodecataves within the human hearing range; imagine if that were the case with octaves. If one does indeed deal with dodecatave equivalence, this fact shapes one's musical approach dramatically. Also, the ed12-edo correspondences fall particularly close to the harmonic series of the NTSC or PAL-M color subcarrier:
| edo
|
ed12
|
NTSC*n
|
PAL-M*n
|
| 1
|
3.5849625
|
3.579545 MHz
|
3.575611 MHz
|
| 2
|
7.169925
|
7.158909
|
7.151222
|
| 3
|
10.7548875
|
10.7383635
|
10.726833
|
| 4
|
14.33985
|
14.317818
|
14.302444
|
| 5
|
17.9248125
|
17.8972725
|
17.878055
|
| 6
|
21.509775
|
21.476727
|
21.453666
|
| 7
|
25.0947375
|
25.0561815
|
25.029277
|
| 8
|
28.6797
|
28.635636
|
28.604888
|
| 9
|
32.2646625
|
32.2150905
|
32.180299
|
| 10
|
35.849625
|
35.79545
|
35.75611
|
| 11
|
39.4345875
|
39.374
|
39.331521
|
| 12
|
43.01955
|
42.953454
|
42.907332
|
| 13
|
46.6045125
|
46.5329085
|
46.482743
|
| 14
|
50.189475
|
50.112363
|
50.058554
|
| 15
|
53.7744375
|
53.6918175
|
53.634265
|
| 16
|
57.3594
|
57.271272
|
57.209776
|
| 17
|
60.9443625
|
60.8507265
|
60.785487
|
| 18
|
64.529325
|
64.430181
|
64.360598
|
| 19
|
68.1142875
|
68.0096355
|
67.936709
|
| 20
|
71.69925
|
71.58909
|
71.51222
|
| 21
|
75.2842125
|
75.1685445
|
75.087931
|
| 22
|
78.869175
|
78.747999
|
78.663442
|
| 23
|
82.4541375
|
82.3274535
|
82.239153
|
| 24
|
86.0391
|
85.906908
|
85.814664
|
| 25
|
89.6240625
|
89.4863625
|
89.390375
|
| 26
|
93.209025
|
93.065817
|
92.965886
|
| 27
|
96.7939875
|
96.6452715
|
96.541597
|
| 28
|
100.37895
|
100.224726
|
100.117108
|
| 29
|
103.9639125
|
103.8041805
|
103.692819
|
| 30
|
107.548875
|
107.38365
|
107.28633
|
| 31
|
111.1338375
|
110.9630895
|
110.894041
|
| 32
|
114.7188
|
114.542544
|
114.437552
|
| 33
|
118.3037625
|
118.1219985
|
118.045263
|
| 34
|
121.888725
|
121.701453
|
121.588774
|
| 35
|
125.4736875
|
125.2809075
|
125.096485
|
| 36
|
129.05865
|
128.860362
|
128.739296
|
| 37
|
132.6436125
|
132.4398165
|
132.247707
|
| 38
|
136.228575
|
136.019271
|
135.860518
|
| 39
|
139.8135375
|
139.5987255
|
135.398929
|
| 40
|
143.3985
|
143.17818
|
143.02444
|
| 41
|
146.41815
|
146.7576345
|
146.600151
|
| 42
|
150.568425
|
150.337089
|
150.175862
|
| 43
|
154.0533875
|
153.9165435
|
153.751373
|
| 44
|
157.73835
|
157.495998
|
157.326884
|
| 45
|
161.3233125
|
161.0754525
|
160.902595
|
| 46
|
164.908275
|
164.654907
|
164.478306
|
| 47
|
168.4932375
|
168.2343615
|
168.053817
|
| 48
|
172.0782
|
171.813816
|
171.629328
|
| 49
|
175.6631625
|
175.3932705
|
175.205039
|
| 50
|
179.248125
|
178.972725
|
178.78075
|
| 51
|
182.8330875
|
182.5521795
|
182.356261
|
| 52
|
186.41805
|
186.131634
|
185.931772
|
| 53
|
190.003125
|
189.7110885
|
189.507483
|
| 54
|
193.597975
|
193.290543
|
193.083194
|
| 55
|
197.1729375
|
196.869975
|
196.658705
|
| 56
|
200.7579
|
200.449452
|
200.234216
|
Table of Ed12s
0…299
See also