Characteristic Specifications Supplemental Information
APx525/526 B Series Audio Analyzers: Analog I/O Specifications 23
525
Bandwidth Limiting Filters
High-Pass
6
DC DC coupling
AC (< 10 Hz) AC coupling Response is 2-pole via a combination
of analog and digital filters, and is
typically –3 dB at 4.1 Hz
Butterworth F
HP
(–3 dB) = 10 Hz to 90 kHz, 4-pole;
10 Hz to 1 MHz (BW52)
Elliptic F
HP
(–0.01 dB) = 10 Hz to 90 kHz,
5-pole; 10 Hz to 1 MHz (BW52);
0.01 dB pass-band ripple;
–60 dB stop-band
Low-Pass
5, 6
ADC Passband No filter is implemented, bandwidth
and response are limited by the A/D
and sample rate (SR)
–3 dB at 0.490 • SR, SR 216 kS/s;
for BW52, add:
–3 dB at 260 kHz for 624 kS/s
–3 dB at 520 kHz for 1.248 MS/s
–3 dB at 1 MHz for 2.496 MS/s
20k (AES17), 40k (AES17) Special filters conforming with AES17
Butterworth F
LP
(–3 dB) = 10 Hz to 90 kHz, 8-pole;
10 Hz to 1 MHz (BW52)
ENBW 1.006 • F
LP
Elliptic F
LP
(–0.01 dB) = 10 Hz to 90 kHz,
8-pole; 10 Hz to 1 MHz (BW52);
0.01 dB pass-band ripple;
–60 dB stop-band
ENBW (1.012–1.062) • F
LP
(varies
due to warping)
Weighting A-wt, B-wt, C-wt, CCIR-1k, CCIR-2k,
CCITT, C-message, 50 s or 75 s
de-emph (with and without A-wt), or
None
Weighting filter is cascaded with both
high-pass and low-pass filters
Input Equalization
Arbitrary 30-pole input filter The EQ operates on any selected ana-
lyzer input channels.