Filters and Frequency Tables
18.0 Filters and Frequency Tables
18.1 Standard
Filters
18.2 Full Range
Frequency Card
Fig 18.1 Frequency and
Component Function
The standard filter provided for the FDS-360 is of the Linkwitz-Riley response
based on two second order Butterworth circuits in series. The response is a
24dB/OCT slope with a 'corner' frequency where the output of the filter if 6dB
down from its pass band level. The use of these filter realisations has been
well documented and provides the best possible phase and amplitude response
for driving large speaker systems.
Table 17.1 lists the component values for various frequencies and should be
used in conjunction with the drawing for the FDS-360F frequency card (See
Figure 18.3). Blank cards, or ready made cards can be provided by any BSS
dealer.
All resistors should be ΒΌW metal film 2% tolerance or better. Capacitors
should be 5% tolerance or better. Figure 18.1 shows how these components
relate to the separate filter blocks to assist in making mixed frequency cards
that might be needed for speaker systems that require gaps or overlaps in the
amplitude response of the filters. Other filter responses can also be realised
using these frequency cards, and your dealer will be able to supply these to
order.
Should the fourth band output be required to work as a full range buffered
output (See section 14.1), a full range frequency card is required to be inserted
into FC3 position. This card removes all filtering associated with the third
frequency point. The limiter setting capacitor C10 should be chosen to suit the
lowest frequency in the band, which would normally be 30Hz. Figure 18.4
shows the frequency card modified for this result.
27
Filters and Frequency Tables
Fig 18.2 Component
Values for Frequency
Cards type FDS-360/1
FDS-360 FREQUENCY CARD COMPONENT SELECTION - 24dB/Octave
Freq.R1R1R5R5C1C10C9
50
60
63
70
80
100
110
125
150
160
180
200
220
250
280
300
350
400
500
600
800
1k0
1k2
1k3
1k5
1k6
2k0
2k5
3k0
3k5
3k7
4k0
4k5
5k0
5k5
6k0
43k 47k 82k 100k 100nF 330nF 150nF
36k 39k 75k 75k 100nF 330nF 150nF
33k 39k 47k 150k 100nF 330nF 150nF
16k - 39k 180k 100nF 330nF 150nF
15k 220k 39k 100k 100nF 220nF 100nF
18k 30k 24k 330k 100nF 220nF 100nF
12k 68k 39k 43k 100nF 150nF 68nF
18k 18k 18k - 100nF 150nF 68nF
7k5 - 15k - 100nF 150nF 68nF
8k2 47k 15k 220k 100nF 150nF 68nF
6k2 - 13k 330k 100nF 150nF 68nF
18k 330k 39k 270k 33nF 150nF 68nF
18k 100k 100k 47k 33nF 100nF 47nF
15k 150k 27k - 33nF 100nF 47nF
13k 180k 43k 56k 33nF 100nF 47nF
15k 47k 27k 150k 33nF 100nF 47nF
15k 27k 39k 39k 33nF 100nF 47nF
10k 56k 18k 330k 33nF 100nF 47nF
6k8 - 15k 150k 33nF 47nF 22nF
6k2 68k 15k 47k 33nF 47nF 22nF
39k 22k 39k 100k 10nF 47nF 22nF
12k 180k 47k 43k 10nF 33nF 15nF
10k 150k 27k 62k 10nF 33nF 15nF
10k 68k 18k 470k 10nF 33nF 15nF
7k5 - 15k - 10nF 22nF 10nF
8k2 47k 22k 39k 10nF 22nF 10nF
8k2 18k 12k 180k 10nF 22nF 10nF
18k 56k 27k - 3n3F 15nF 4n7F
15k 47k 24k 470k 3n3F 15nF 4n7F
10k 330k 24k 100k 3n3F 15nF 4n7F
39k 12k 27k 56k 3n3F 15nF 4n7F
10k 56k 39k 30k 3n3F 15nF 4n7F
8k2 100k 18k 100k 3n3F 10nF 3n3F
6k8 - 18k 56k 3n3F 10nF 3n3F
6k2 - 13k 270k 3n3F 10nF 3n3F
6k2 68k 15k 47k 3n3F 10nF 3n3F
28
FDS-360 FREQUENCY CARD COMPONENT SELECTION - 24dB/Octave
See Notes at bottom f or f ul l c om ponent ID.
Freq. R1A R1B R5A R5B C1A C10 C9
6k3
6k5
7k0
7k5
8k0
8k5
9k0
9k5
10k0
12k0
15k0
18k0
20k0
R1A
R1B
R5A
R5B
C1A
C9
C10
27k 6k8 27k 18k 3n3F 10nF 3n3F
22k 6k8 12k 82k 3n3F 10nF 3n3F
39k 5k6 13k 39k 3n3F 10nF 3n3F
10k 8k2 18k 18k 3n3F 6n8F 2n2F
10k 7k5 10k 62k 3n3F 6n8F 2n2F
4k7 27k 8k2 330k 3n3F 6n8F 2n2F
3k9 120k 8k2 100k 3n3F 6n8F 2n2F
15k 56k 82k 33k 1n0F 6n8F 2n2F
15k 47k 43k 47k 1n0F 6n8F 2n2F
12k 43k 27k 62k 1n0F 6n8F 2n2F
7k5 - 15k - 1n0F 6n8F 2n2F
6k2 - 15k 82k 1n0F 6n8F 1n0F
5k6 - 13k 82k 1n0F 6n8F 1n0F
=
R1A , R2A, R3 A , R4A, R6 A, R8 A
R1B , R2B, R3 B , R4B, R6 B, R8 B
=
=R5A, R7A
=R5B, R7B
=
C1A, C1B, C2, C3, C4A, C4B, C5, C6, C7, C8
=C9
=C10
Fig 18.3 FDS-360F
Component Overlay
Fig 18.4 FDS-360F Full
Range Overlay
C1A
C1B
R1A
R1B
R2A R4A
R2B
C10
C9
C2
116
C4A
C4BC3
R3A
R3B
R4B
R5A
C6
R6B
R6A
C5
R7A
R7BR5B
C7
C8
R8B
R8A
29
Loading...