Aquarian Audio H2dX Hydrophone User Guide
- June 3, 2024
- Aquarian Audio
Table of Contents
Aquarian Audio H2dX Hydrophone
The H2dX hydrophone is designed to offer great sensitivity and low self noise in the human auditory range while being rugged, compact and affordable. Its small, streamlined shape and high specific gravity will help maintain a low working depth in mild wind and currents. Its compact size and flexible cable make it very portable and simple to use. It can be used with any microphone preamp with mating connector and phantom power. In most cases, these preamps will be built into a digital recorder, mixer, professional video camera or PA system.
Using the H2dX
The H2dX 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 and will need to be switched on in your device. Any standard phantom power supply voltage will work. Do not exceed +48V when powering the H2dX. If your recorder or mic preamp offers options for phantom voltage, we recommend using the lowest voltage available for lowest noise and power consumption. 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 H2dX. It is designed to withstand corrosion from seawater and the impact of accidental drops2. Try to keep the output plug clean and dry and avoid unnecessarily rough handling 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 prematurely corrode the output plug. Making an extra effort to coil the cable neatly when retrieving the hydrophone will help avoid problems with tangles as the cable ages. Most importantly, protect the cable from cuts and abrasions! The H2dM uses a custom-made cable with a very durable PU 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 conduit, 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 configuration can be beneficial for common-mode noise reduction when used with a balanced input device. The H2dX runs single-ended. It is a simple output plug variation of our standard H2dM. Single-ended operation lowers cost (mostly because it allows the use of a coaxial cable) and power use. Common-mode noise is seldom a problem in most hydrophone applications and the hydrophone is well shielded from electrical noise. Nearly all microphone preamps now are electronically balanced and tolerate this well, so this single-ended configuration is generally advantageous overall.
- The H2dM uses a plate sensor on the end opposite the cable—somewhat like a microphone diaphragm. It is extremely crush-resistant with radial loads, but may be damaged if dropped on its end. It is quite tough for what it is, but note that it is a sensitive instrument. Avoid throwing it into the water, or any other activity that may result with an impact to the hydrophone. One great advantage of this design is that it is easy to repair if necessary. Contact Aquarian for support.
Specifications
Specifications are dependent upon the audio device to which the H2dX is
connected. The output impedance of the H2dX is set by the phantom power supply
from the audio device with which the hydrophone is used. Gain of the signal
conditioning amplifier in the H2dX is related to the bias current and input
impedance of the mic preamp. High-frequency performance is also limited by the
output impedance of the hydrophone and the cable impedance—which is a function
of length. For all of these reasons, we do not publish detailed response plots
for this design. 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.
The following specifications are based on typical response when using the H2dX
with a standard 48V phantom power supply (48V with 6.8K pull-up resistors):
- Sensitivity: -165dB re: 1V Pa (+/- 4dB 20Hz-4KHz)
- Useful range: <10 Hz to >100KHz (not measured above 100KHz, approximate sensitivity @100KHz = -210dB re: 1V/Pa)
- Polar Response: Omnidirectional (horizontal)
- Operating depth: <80 meters
- Output impedance: 6.8 K (typical)
- Power: 1.2 mA (typical)
- Physical: (cable and output plug excluded)
- Dimensions: 25mm x 46mm
- Mass: 105 grams
- Specific Gravity : 5.3
Warranty Statement
Aquarian Audio warrants the H2dX 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.
Corroded output plugs are not covered under warranty. Additional terms and
conditions apply. For full details please view our general warranty statement
at
http://www.aquarianaudio.com/warranty.html
Aquarian Audio & Scientific
A division of AFAB Enterprises
5677 Patricia Lane Anacortes, WA 98221 USA
360-299-0372
www.AquarianAudio.com
[email protected]