User Manual - Aquarian Audio
Aquarian Audio Products
H2a-XLR Hydrophone User’s Guide
Thank you for purchasing your Aquarian Audio Products H2a-XLR hydrophone. This
hydrophone is designed to provide high-quality audio performance in a low-cost device. It is very
durable and will interface directly with professional audio microphone preamps. It offers very good
sensitivity and low noise in the human auditory range. The H2a-XLR’s streamlined shape and
high specific gravity will help to maintain a low working depth in a moving water column. Its
compact size and the easy hand of its cable make it very portable and simple to use.
Using the H2a-XLR
The H2a-XLR is terminated with a 3-pin male XLR plug. Wiring is standard: pin 1 is
ground, pin 2 is hot and pin 3 unused1. This configuration should be compatible with any standard
female XLR microphone jack. Phantom power is required. Any standard phantom power supply
voltage will work. Do not exceed +48V when powering the H2a-XLR. With the connection firmly
made and phantom power switched on, there’s nothing more to do but adjust levels and take in
the sounds of the deep.
Hydrophone care
No special care is required for the H2a-XLR. It is designed to withstand corrosion and the
impact of accidental drops, but making an attempt to keep the output plug clean and dry and
avoiding unnecessarily rough handling will help to ensure the long-term stability of the product. It
is best not to store the hydrophone in a waterproof enclosure. Doing so will trap moisture, salts
and minerals that are left on the hydrophone and cable after deployment and increase corrosion
problems with the output plug. Making an extra effort to coil the cable nicely when retrieving the
hydrophone will help avoid problems with tangles as the cable ages. Most importantly, protect the
cable from cuts and abrasions! The H2a-XLR uses a custom-made cable with a very durable
urethane jacket. However, it is also designed to be compact and flexible. Kinking the cable,
walking on it, or dragging it over a sharp or abrasive surface may damage the cable sheath and
eventually cause the hydrophone to fail. Both aquatic and terrestrial animals may attack the cable
in an unattended application. Using some kind of cable shroud, such as plastic tubing, can help
protect the hydrophone in long-term installations.
Most XLR-terminated microphones are balanced and use Pin 3 for a cold (or low) side of the signal,
which has the same output impedance and is typically complimentary to the signal on Pin 2. This
confirguration can be beneficial for common-mode noise reduction when used with a balanced input
device. The H2a-XLR runs single-ended. It is a simple output plug variation of our standard H2a.
Single-ended operation is preferable in most hydrophone applications because common-mode noise is
seldom a problem and the hydrophone consumes less power and has a quieter output with the singleended drive. The H2a-XLR is very well shielded. The single-ended drive should not be an issue even in
very noisy environments and should work well with all phantom powered balanced mic inputs.
The H2a-XLR is intended to be a lower-cost and easy-to-use alternative to military and lab-grade
hydrophones. Deriving high sensitivity and low noise were made a priority over maintaining strict
tolerances. The following specifications are typical of a limited sample group and are not
guaranteed. They are for basic comparison information only.
Specifications are dependent upon the audio device to which the H2a-XLR is connected. The
hydrophone sensor is capable of picking up sounds from below 20Hz to above 100KHz. The
output impedance of the H2a-XLR is set in part by the phantom power supply from the audio
device with which the hydrohone is used. Hi-frequency performance is also limited by the output
impedance of the hydrophone and the cable impedance—which is a function of length. Please
also note that further limitations in your overall system may result from the sampling rate of digital
recorders and by the input stage of your audio device’s microphone preamp. Despite the
uncertainties of above, you should expect to easily capture the entire human auditory range of
20Hz to 20KHz.
The following specifications are based upon using the H2a-XLR with a classic 48V phantom
power supply (48V with 6.8K pull-up resistors):
Useful range:
-180dB re: 1V/µPa
<10 Hz to >100KHz
Polar Response:
Operating depth:
Output impedance:
<80 meters
1 KΩ
0.6 mA
Specific Gravity:
25mm x 46mm
105 grams
(+/- 4dB 20Hz-4.5KHz)
(not measured above 100KHz, approximate sensitivity
@100KHz = -220dB re: 1V/µPa)
(cable and output plug excluded)
Warranty Statement
Aquarian Audio Products warrants the H2a-XLR Hydrophone from electrical failure or defects in
workmanship for a period of one year following the date of purchase. Warranty claims or repairs
can be made directly through Aquarian Audio Products. Corroded output plugs are not covered
under warranty. Additional terms and conditions apply. For full details please view our general
warranty statement at
Aquarian Audio Products
A division of AFAB Enterprises
1004 Commercial Ave. #225 Anacortes, WA 98221 USA
(360) 299-0372
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF