1. Why doesn’t my SoundTrap show up in the calibration database?

You’re probably using the wrong serial number. At the beginning of 2019 we changed from 8 digit hardware serials to 4 digit assigned serials. Using old software with new SoundTraps will yield the wrong serial. To see the correct serial please update your SoundTrap Host version to V3.3.3 or later. The new four digit serials are also printed on the recorder, visible through the top window.

2. Can you supply a frequency response curve for my SoundTrap?

Every SoundTrap comes with a piston phone calibration at 250 Hz and is specified to have flat response across its full bandwith +/- 3 dB. We do not provide full calibration curves (‘tank calibration’). To obtain this type of calibration please contact a third party calibration facility such as NPL in the UK.

3. Which memory cards can I use in the ST500?

Any  of the Samsung Evo cards >= 128GB including Evo, Evo-Plus and Evo -Select. The Evo-Plus cards consume about 8% more power than the others, so are less desirable. As of January ’20 we have only done limited testing of the new 512 GB cards – these consume slightly more power than the 128 GB cards and it will take another year to have confidence of long term reliability. Also note that idle cards consume some power, so fewer cards = more battery endurance. The latest version of our endurance calculator spreadsheet takes this into account.

4. What battery does the SoundTrap remote use?

Our white remotes use CR2032 and the (newer) black ones use CR2025.

5. Do you have a European / American / xxx distributor?

In order to keep prices down, all sales are direct from New Zealand. Where this is a problem, you may need to find a local importer to purchase them for you.

6. What discounts are available?

We generally don’t discount our products, but instead try to keep our regular pricing as low as possible. We may be able to offer a small discount for large orders (>10 units), but this will be dependent on many factors, one being that we are given plenty of notice before a large order is required ie 12+ weeks.

7. Can you provide the ST300 / ST4300 internal battery specifications?

Lithium Ion, two cell battery, 3.7V, 4000mAh, 4.8Wh, 70g total weight

8. How do I install the PRV valve?

PRV Installation Procedure:
We strongly recommend this is carried out by someone with experience servicing underwater equipment, eg a scuba technician. The procedure is as follows:
1. Unscrew gold/silver coloured plug from the housing base using an allen key (3/16″ for gold plug, 4mm for silver).
2. Ensure sealing surface is perfectly clean.
3. Ensure PRV has good clean o’rings installed. 
4. Screw PRV into recorder base using a small crescent wrench being careful not to over tighten.

9. Can I use my existing XYZ hydrophone with an ST500/ST4300?

To work with SoundTrap hydrophones must meet the following criteria:


  1. Be pre-amplified
  2. Operate from 3 V supply voltage
  3. Current consumption of ~2mA or less
  4. The correct connector – Subconn MCBH3M
  5. Connector pin assignment – PIN1=PWR, PIN2=GND, PIN3=SIG.
  6. Have suitable gain, noise floor and frequency response for the application.

10. Why am I getting errors when offloading files?

Errors during offload indicates a problem with the USB connection. Please check the following:


  1. That your SoundTrap has enough battery remaining to communicate – leave to charge until it indicates at least 20%.
  2. That you are plugging the SoundTrap directly into the computer ie not via a hub, extension etc
  3. That no other devices are plugged into the same set of USB sockets eg external an harddrive
  4. That the cable and wet connectors are in good condition (clean or replace as necessary).
  5. Failing all these, please try an alternative computer.