dCS 954 User Manual | Manual for Standard Software Version 1.5x |
dCS Ltd | June 2000 |
|
|
Frequency Response
The overall frequency response is determined by the sample rate, the digital filter and the analogue filter. If imaging is to be avoided, all filters must
At a sample rate of 44.1kS/s, a flat 20kHz pass band must be maintained with at least 80dB of attenuation above Fs/2 (22.05kHz). This allows barely 2kHz margin between the pass band and the stop band for the filter to do its work, necessitating a very sharp filter.
At sample rates of 88.2kS/s and above, there is so much extra bandwidth available that maintaining a flat 0 - 20kHz audio band is less of a problem. This allows more relaxed filters to be used, resulting in extra sonic benefits.
Frequency responses for all 7 PCM sample rates, set to Filt1, are shown below.
Level (dB)
|
| Filter 1 Frequency Responses |
|
|
|
| dCS 954 SW v1.30 |
|
|
6 |
|
|
|
|
0 |
|
|
|
|
32k | 48k | 96k |
|
|
|
|
|
| |
|
|
|
| DSD |
| 44.1k | 88.2k | 176.4k | 192k |
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
| |
0.02 | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 | |||
|
|
|
|
|
|
| Tone Frequency (kHz) |
|
|
|
|
|
|
Figure 27 – Filter 1 frequency responses
Manual part no: DOC136954 iss 2B1 | Page 47 | file 135954ma2b1.pdf available from website |
Contact dCS on + 44 1799 531 999 | email to: more@dcsltd.co.uk |
(inside the UK replace + 44 with 0) | web site: www.dcsltd.co.uk |