The DPS Core lattice filter EQ has been specialized for “musical” audio quality. As a result of experimentation, Q (bandwidth) is wider at frequencies above 10kHz. DPS for ARM processors and other standard filters uses normal biquad functions for best performance. Therefore, a standard EQ does not exhibit this widening above 10kHz. Q values must be set higher in DPS Core to match a standard EQ. This table describes the current discrepancy between the platforms:
Freq –>
Norm Q |
10KHZ
DPS Q |
11K2Hz
DPS Q |
12K5Hz
DPS Q |
14K1Hz
DPS Q |
16KHz
DPS Q |
18KHz
DPS Q |
20KHz
DPS Q |
0.4 | 1.0 | 1.0 | 1.0 | 1.4 | 1.4 | 2.0 | 2.0 |
0.5 | 1.2 | 1.2 | 1.2 | 1.4 | 2.0 | 2.0 | 2.5 |
0.6 | 1.2 | 1.2 | 1.2 | 1.4 | 2.0 | 2.0 | 2.5 |
0.7 | 1.4 | 1.4 | 1.4 | 2.0 | 2.0 | 2.5 | 3.0 |
0.8 | 1.4 | 1.4 | 1.4 | 2.0 | 2.5 | 2.5 | 3.0 |
0.9 | 2.0 | 2.0 | 2.0 | 2.5 | 3.0 | 3.0 | 4.0 |
1.0 | 2.0 | 2.0 | 2.0 | 2.5 | 3.0 | 3.0 | 4.0 |
1.2 | 2.0 | 2.0 | 2.0 | 3.0 | 3.0 | 4.0 | 4.0 |
1.4 | 2.5 | 2.5 | 2.5 | 3.0 | 3.0 | 4.0 | 5.0 |
2.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 5.0 | 5.0 |
2.5 | 4.0 | 4.0 | 4.0 | 5.0 | 5.0 | 6.5 | 6.5 |
3.0 | 5.0 | 5.0 | 5.0 | 6.5 | 6.5 | 6.5 | 8.0 |
4.0 | 6.5 | 6.5 | 6.5 | 8.0 | 8.0 | 8.0 | 8.0 |
5.0 | 6.5 | 6.5 | 6.5 | 8.0 | 8.0 | 8.0 | 8.0 |
6.5 | 8.0 | 8.0 | 8.0 | 8.0 | 8.0 | 8.0 | 8.0 |
8.0 | 8.0 | 8.0 | 8.0 | 8.0 | 8.0 | 8.0 | 8.0 |