dBu = dBv
dBu = 20 * log (Voltage / .775 V)
P = V^2 / R
.001 W = V^2 / 600 W
V^2 = .001 W * 600 W
V = sqrt (.001 W * 600 W)
V = .775 Volts
dBm = dBVU
dBm = 10 * log (Power / 1mW)
dBV = 20 * log (Voltage / 1V)
Professional vs. Consumer Levels
+4 dBu = 20 * log (voltage / .775 V)
voltage = 1.228 Volts
-10 dBV = 20 * log (voltage / 1V)
voltage = 0.3162 Volts
20 * log (1.228V / 0.3162V) = 11.79 dB
dBspl
dBspl = 20 * log (Pa / .00002 Pa)
| dB | Compares | Reference Level | Formula |
| dBspl | Sound Pressure | 0.00002 Pa | 20 * log (spl / .00002 Pa) |
| dBm | Electrical Power | 1mW | 10 * log (Power / 1mW) |
| dBu | Voltage | 0.775V | 20 * log (Voltage / .775V) |
| dBV | Voltage | 1V | 20 * log (Voltage / 1V) |
| dBFS | Sample Level | 65536 | 20 * log (Sample Level / 65536) |
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5 string bass |
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B |
E |
A |
D |
G |
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Freq |
31 |
41 |
55 |
73 |
98 |
196 |
392 |
784 |
1568 |
3136 |
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1/2 x ms |
16 |
12 |
9 |
7 |
5 |
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ms |
32 |
24 |
18 |
14 |
10 |
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2 x ms |
64 |
48 |
36 |
28 |
20 |
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7 String Guitar |
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B |
E |
A |
D |
G |
B |
E |
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Freq |
62 |
82 |
110 |
147 |
196 |
247 |
330 |
659 |
1319 |
2637 |
5274 |
10548 |
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1/2 x ms |
8 |
6 |
4.5 |
3.5 |
2.5 |
2 |
1.5 |
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ms |
16 |
12 |
9 |
7 |
5 |
4 |
3 |
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2 x ms |
32 |
24 |
18 |
14 |
10 |
8 |
6 |
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Freq |
20 |
25.2 |
31.7 |
40 |
50.4 |
63.5 |
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ISO |
20 |
25 |
31.5 |
40 |
50 |
63 |
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1/2xMS |
25 |
20 |
15.9 |
12.5 |
10 |
7.9 |
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ms |
50 |
40 |
31.7 |
25 |
200 |
15.9 |
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2xMS |
100 |
80 |
63.5 |
50 |
40 |
31.7 |
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Freq |
80 |
100.8 |
127 |
160 |
201.6 |
254 |
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ISO |
80 |
100 |
125 |
160 |
200 |
250 |
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1/2xMS |
6.3 |
5 |
4 |
3.1 |
2.5 |
2 |
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ms |
12.5 |
10 |
8 |
6.3 |
5 |
4 |
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2xMS |
25 |
20 |
16 |
12.5 |
10 |
8 |
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Freq |
320 |
403.2 |
508 |
640 |
806.3 |
1015.9 |
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ISO |
315 |
400 |
500 |
630 |
800 |
1000 |
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1/2xMS |
1.6 |
1.3 |
1 |
0.8 |
0.6 |
0.5 |
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ms |
3.2 |
2.5 |
2 |
1.6 |
1.3 |
1 |
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2xMS |
6.3 |
5 |
4 |
3.2 |
2.5 |
2 |
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Freq |
1280 |
1612.7 |
2031.9 |
2560 |
3225.4 |
4063.7 |
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ISO |
1250 |
1600.0 |
2000 |
2500 |
3150 |
4000 |
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1/2xMS |
0.4 |
0.3 |
0.3 |
0.2 |
0.2 |
0.1 |
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ms |
0.8 |
0.6 |
0.5 |
0.4 |
0.3 |
0.3 |
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2xMS |
1.6 |
1.3 |
1 |
0.8 |
0.6 |
0.5 |
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Freq |
5120 |
6450.8 |
8127.5 |
10240 |
12901.6 |
16255 |
20480 |
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ISO |
5000 |
6300 |
8000 |
10000 |
12500 |
16000 |
20000 |
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1/2xMS |
0.1 |
0.1 |
0.1 |
0.1 |
0 |
0 |
0 |
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ms |
0.2 |
0.2 |
0.1 |
0.1 |
0.1 |
0.1 |
0.1 |
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2xMS |
0.4 |
0.3 |
0.3 |
0.2 |
0.2 |
0.1 |
0.1 |