NOAA Technical Memorandum NMFS - Southwest Fisheries ...

M icrophone
Hydrophones 1 2 3 4 5 6 7
Mic Inputs 1 2 3 4 5 6 7 8
Mackie Mixer CR104VLZ
Equalizers
Faders
Direct Outs 1 2 3 4 5 6 7 8
Input 1 2 3 4 5 6 7 8
Tascam DA38 8-track
Output 1 2 3 4 5 6 7 8
9 10 11 12 13 14 15 16
9 10 11 12 13 14 15
Inserts In&Out
9 10 11 12 13 14 15
Equalizers
1 2 3 4 5 6 AuxSend
L/R Mix Select
33
1-2 M ix Select
R input L
Sony R-500 DAT
R output L
DBX Crossover
1 2 3 4 5 6 7
Avens Band Pass Filter
1 2 3 4 5 6 7
Low
Mid
High
Ishmael
Single Line
Multiple Lines
8
8
Left
Record to HardDisk
Headphones
Headphones
Figure 3. Hardware wiring diagram for shipboard routing and processing of acoustic
signals from the towed hydrophone array. The Sony R-500 DAT recorder (shown here)
was wired to a pair of sonobuoy receivers on most cruises.
Gain (dB)
32.0
30.0
28.0
26.0
24.0
Mackie + Tascam Calibration 8/13/05
100 1000 10000 100000
Frequency
Chan 2
Chan 3
Chan 4
Chan 1
Figure 4. System frequency response for signals that pass through the Mackie CR1604-
VLZ mixer, are recorded on the Tascam DA-38 digital tape recorder, and are played back
on the Tascam. An AC voltage of 0.1 V RMS was sent to the Mackie over a frequency
range of 500 Hz to 20 kHz, was amplified and filtered with an analog equalizer, and was
recorded to tape. The output voltage was measured during playback. Equalizer settings
were unity gain (high), -15dB @ 100Hz (mid), -15dB (low). Only four of eight channels
were calibrated.