H1a Hydrophone
Passive general purpose listening hydrophone, durable, self-weighted. Works directly with instrument amplifiers or similar High-Z inputs.
Regular price
$206.00
- Great for listening to marine animals through an amplified instrument speaker
- Good sensitivity and low noise across the human auditory range
- Robust design handles accidental drops and temperature extremes
- Self-weighted to keep hydrophone down in water, including currents
What's Included:
- H1a Hydrophone
- Semi-rigid EVA travel case (not waterproof), excluded when length is over 20-meters
We are committed to prompt service. Many standard hydrophone variants are kept in stock and often ship the next business day. Custom builds are frequently completed within one week, depending on quantity and configuration.
We ship worldwide using trusted carriers including UPS, FedEx, DHL, and USPS. Shipping rates are calculated at checkout. International customers may be responsible for import duties, taxes, or brokerage fees assessed at delivery by their country and carrier.
Transit times and customs clearance can occasionally cause delays outside our control. Customers using their own courier account, freight forwarder, or uninsured shipping methods assume additional responsibility once the shipment leaves our facility.
For complete details on shipping methods, insurance, international shipments, delays, freight forwarding, and liability terms, please see our full Shipping Policy.
- Aquarian made products are backed by a 1-year limited warranty covering defects in materials and workmanship under normal use.
- Resold products manufactured by third parties may be covered by the original manufacturer’s warranty, where applicable.
- Returns of unused, like-new products are generally accepted, subject to inspection and approval.
Please review our full policies for details on custom products, misuse conditions, returns, exclusions, and limitations.
Connector
1/4 Inch TS (Tip-Sleeve) Mono Phono
Common on high-Z inputs (high input impedance) on instrument amplifiers.
BNC Connector
Common on test and measurement devices, such as oscilloscopes, spectrum analyzers, and data acquisition devices (DAQs).
Additional connector types may be available for specialized applications. Contact us with your equipment requirements for pricing and lead time.
Custom Cable Length
While we can make any length of cable, performance can be impacted above 30-meters. Long cables affect high-frequency response. Consider cable capacitance, input impedance, signal conditioning, and required bandwidth.
The H1a is intended to be a lower-cost alternative to military and lab-grade hydrophones. Deriving high sensitivity and low noise from lower-cost components were made a priority over maintaining strict tolerances. These specifications are typical of a limited sample group and are not guaranteed. They are for basic comparison information only.
| Sensitivity | -185 dB re: 1V/µPa | ±4 dB, 20 Hz–4 kHz |
| Useful range | <1 Hz to >100 kHz 1 |
Not measured above 100 kHz; approximate sensitivity @100 kHz of -220 dB re: 1V/µPa |
| Capacitance | 20 nF | |
| Polar response | Omnidirectional (horizontal) | |
| Operating depth | <80 meters | |
| Physical | Cable and output plug excluded | |
| Dimensions | 25 mm × 46 mm | |
| Mass | 105 grams | |
| Specific gravity | 5.3 | |
1 Please note that we have specified a very wide useful range for this hydrophone because they are often used for simple detection and timing applications with high-amplitude ultrasound devices, such as acoustic beacons and anti-fouling systems. Take special note that sensitivity is substantially reduced at high frequencies. Note the linear range in the sensitivity specification. If needing a broadband hydrophone, consider the S1.
The H1a utilizes a passive piezo sound pickup. There is no preamp or impedance buffer circuit within the hydrophone. The advantages are that the hydrophone remains as simple and low cost as possible, it does not require any power, and it offers a very wide dynamic range. System gain and input impedance must be considered while choosing a preamp.
System gain is the amount of signal amplification required and will depend on the amplitude of the sounds that you are attempting to monitor, as well as what you are doing with the output. Generally speaking, if you are driving headphones or a line audio circuit, or working with a computer sound device, you may require 20 dB of gain for industrial monitoring, 40–50 dB for listening to cetaceans and large aquatic wildlife, and 60 dB or more for very distant or faint sounds.
Input impedance is the amount of load that your preamp puts on the hydrophone. The low-frequency response of a piezo transducer, such as that used in the H1a, will be limited by the input impedance of the preamp. Higher input impedance will give you an extended low-frequency response. This relationship can be calculated for the H1a with the following formula:
Fc = 1 / 0.000000157 * R
Fc is the frequency at which electrical output is 3 dB down from nominal and R is the input impedance of your preamp. Therefore, using a preamp with an input impedance of 300 kΩ will give you a low-frequency cutoff of 20 hertz—the low end of what humans can hear. A preamp with an input impedance of 100 kΩ might work well for the PA system on a whale-watching vessel, giving a Fc of 64 Hz, which is compatible with the capabilities of most speaker systems. The higher Fc might also help filter the extreme low frequency noise of the hydrophone rising and falling in the water as the boat moves on a swell.
Use directly with instrument or High-Z amplifier inputs
- One example that we resell is the Honeytone amplified speaker
- Get them together: Whale Watch Listening Kit.
- Get them together: Whale Watch Listening Kit.
To use with powered microphone inputs, use a powered adapter
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3.5mm (1/8") TRS Microphone Input Or instead, select the H2d Hydrophone with 3.5mm (1/8") TRS output |
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XLR microphone input Or instead opt for the H2d Hydrophone with XLR output |