Monday, July 18, 2011

Review: Two New Ultrasonic Bat Detectors From Batomania - Part 1 Of 2

I've recently had the opportunity to test and review two new offerings, from Batomania, in Germany. The Horchbox 2.0: which is designed for field deployment / unattended logging of bat activity. And, the Minihorchbox: which could be considered a pocket-sized version of it's big brother. But, despite it's small size - It's also intended for long-term logging of bat calls.

So, I can't comment directly on how functional or effective the material is. The manufacturer does cover the topic of how waterproof the units are; and describes best practices, for outdoor deployment - In the Quick Manual (for one example). It is currently available in both the German or English language. It will be among the files, when you download & install the free Horchbox software.
The Quick Manual is concise, and basically tells you everything you would want to know about these units.
I urge you to look it over. I've pasted the English version at the bottom of this post.

There are a few features that make these two new bat detectors unique:

* They are capable of recording many bat passes, directly onto SD cards.
* They are especially great for unattended monitoring/recording.
* They are very easy to use, and no PC is needed for the actual recording.

In many ways, these new units from Batomania are perfect for my nightly recordings. Until now, I haven't had the opportunity to test or review equipment that was quite like this: Fairly self-contained, and reasonably weatherproof.

In the case of the Horchbox 1.5/2.0: It's very robust and solidly built. It is very well suited to deployment in the field. Especially in a safe location; since the unit does not currently feature any anti-theft measure. Luckily, in most cases, this is not a major concern.
The other neat attribute I like, is how the MEMs microphone element is protected.  by a thin gray material. I reckon it's well done, since it appears to be sufficiently shielded. I have not used (either unit) in inclement weather. I'm always reluctant to do so, with any detector.

In the case of the Minihorchbox: It's very compact and portable (see pics in previous posts). It'll fit in any pocket! I really like the fact that it's internal battery gets charged, by plugging it into one of your PC's USB ports. So, fumbling with batteries is never an issue. As with most bat detectors, the sensitivity is selectable.

Here is a screenshot, of a typical call listing window, from the Minibox:

I found both units to be excellent performers. They have neat features, and are sensitive, with great pick-up range. The fact that all bat calls are recorded directly to SD cards is great! I like the fact that options for Time Delayed 10x (AKA time expanded) playback is available; within the Horchbox interface. Please see the second half of my review, Part 2 Of 2!

Quick Manual Horchbox/Minibox


The Horchbox and Minibox are sophisticated bat call recording devices. In principle, they work the same way. The difference is that the Minibox is very small, and includes an internal battery. Whereas the Horchbox has a bigger enclosure; and standard rechargeable battery packs are used. The Software for configuring the devices, and analyzing the data is the same. There are only minor differences in handling. This manual describes all the steps used for both devices, and acknowledges whichever differences are important.


The basic handling and functions, are depicted directly on the devices (on the outside of the Minibox, and inside the box, for the Horchbox). Here are some differences you will see when comparing the two devices:
- External sleep mode is activated using a key for the Horchbox, whereas the Minibox utilizes a switch.
- Since the Minibox has an internal battery, there is a power on/off switch. Whereas the Horchbox has just a
  battery connection.
- For improved robustness against weather, the Minibox has a neoprene bag. Weather protection may also be improved by using the special alloy cover (included). The Horchbox is just fine, the enclosure has about the same level of protection as the Minibox does, with it's bag and the alloy cover.
- To open the Horchbox you need one flathead screwdriver, whereas the Minibox does not need anything special.
- The battery for the Horchbox is charged using an external charger, whereas the Minibox is charged simply by using a USB connection.

Setup for recording and placement outside

Please be sure that the battery is charged and the SD-Card does not contain any important data. Everything on the SD-Card is deleted when the Horchbox is activated! Place the SD-Card in the card slot, connect the
battery (for the Horchbox) or switch, on the Minibox. The front LED will give you some feedback:
- Repeated fast blinking: Indicates the SD Card is not inserted properly.
- Steady blinking, 1 to 5 times: Indicates the charge level of the battery (1 nearly empty - 5 quite fully charged)
So normally, you will get some blinking from the front (green) LED. Then the box stops showing external activity, so as to reduce discovery by bypassing people.
If you look at the circuit board inside the box (on the Horchbox), or the rear panel (on the Minibox): There
are two small LEDs. One is blinking regularly, whereas the other becomes active when sound is recognized by the unit. This way you can confirm that everything is OK.
Now the box is ready to be placed at the location of your choosing. If you want, you can switch the key-lock to Inactive (vertical/green dot on the Horchbox) or simply move the Sleep switch to the Sleep position (on the Minibox). This is useful, for keeping the unit from recording, until you are ready to place the box in position. After you switch the key-lock to active (horizontally/red dot for the Horchbox) or reactivate the switch on the Minibox, it will indicate the battery status again, via the LEDs on the front.
Please check that the box is located in such a way:
- That it is not easily detected by bypassing people.
- That the microphone does not get wet; for example do not place the box with the microphone facing up. Try to position the unit, so that the microphone
  is not exposed to direct precipitation.
- So that it is partially sheltered against wind, so that it does get moved out of position.
When you get back to the instrument, you can either just disconnect the battery (Horchbox) or switch it off (Minibox).
Then be sure to remove the SD-Card before you reactivate it again, to avoid loosing all the recorded data.
When you insert the SD-Card into your PC, it may prompt you to format it. Do not format the SD Card! The message appears because Windows can not handle the card. This is why you need the PC software Horchbox.exe to read the data. Using this software you can analyze and/or export the data in Wav/Raw format.

Installation and Configuration

To change the behavior of the devices, you may configure them using a PC. Therefore, you need to connect the boxes using the USB cable. When doing this the first time, the PC may request to install a driver. Use the driver included on the SW-ZIP file. This should normally work with Windows XP/Vista/Windows 7. There are two drivers: one for 32-Bit, and one for 64-Bit operating systems.
After the drivers are installed, you can start the Horchbox software. There are three typical actions you might do:
-Import recordings from an SD Card, or from a previously generated image, or configure the Horchbox. For now, we want to do the last one. Therefore connect the device; without SD Card and no battery (for the Horchbox), to the PC using the USB cable. The PC might take a few seconds to recognize the device. Afterwards, click on Configure HW; and the software will search for the box. Normally it will find the box and ask you if it should connect to it. Answer with Yes. There will be a window showing you all the device options. Among the main things you might want to do are:
- Set the internal clock. This is done every time you click on the 'Write Config to Box' button.
- Put some personal identifier on: Box Name and Comment.
- Modify the trigger scheme: You may either use Threshold or Bat Detect. Threshold should only be used at
locations without much noise, or other sounds. Normally, Bat Detect is the preferred selection: The box tries
to record sounds, which are similar to bat calls.
- There is also a Sensitivity value which you can use to select the level for the triggering. This does not
influence the loudness of the recordings – It only decides whether or not a recording is made. All recordings
are made the same way, and do not depend on the selected sensitivity. Please be aware, that there is an
internal dampening system – So the sensitivity of the microphone can be reduced by the box itself, when a bat is quite close to the box. This behavior is not user configurable.
- The value of Noise Level should be kept at 5. If you intend to use the box in very noise environments like
highways or wind turbines, you might try to increase this value (maybe up to 15). You may need to do
some guess work, and try to find a good value for special applications.
- The Rain Filter check-box helps reduce recordings of raindrops, but you might miss some bats also.
- Finally, you can decide how to record: Each recording will have a duration of at least the number of seconds
you enter at Rec. Duration. If you check Extend, it will be extended as long as bat activity is recognized (up
to 11 Seconds). Then there will be a short (less than 0.1 second) pause, before the next recording will start
- And finally, you can select the Sample-rate depending on your needs. The higher the sample-rate, the more
data will be generated per second (200 kHz->400 kByte/s, whereas 600 kHz takes 1.2 MByte/s).
- At the bottom you will see some global control strategies for sleeping/recording. You can select light
thresholds and time dependent sleeping.
- Newer boxes might have some extended parameters, such as:
- Switch off voltage: The box will shutdown when the battery reaches a certain voltage level. This prevents
the battery from damage by deep discharge. Please be sure to select a voltage according to your
battery. For 7.2 Volt batteries 6 Volts is a good value.
- Send Data All: This selects how often a data sample is sent to the Internet. The box will not record while
the data is sent, typically it takes 5 minutes. While doing this, the box takes a lot more power than
normal, so each data sample sent will reduce the battery time by approximately one hour. Good values
are maybe 6 or 12 hours.
- GPS mode only: Normally the GPS is only switched on when a data sample is sent. This is fine,
because for general usage, the box is placed somewhere and kept there. If you want to use the box as a
mobile device - While walking/driving, and you are not interested in online data, but you still might want to know
where you went (and also where recordings took place). Then you can activate this check-box, and the
GPS will always be active. This takes some more power, but under the described conditions you are not
going to be using the box for 5 days (or similar).
There are some more things in the menu of the window. You can load configurations, and also save them to a file. In addition, the Menu window allows you to do a firmware update:

Firmware update

When you select Firmware update in the Hardware menu, you can update the firmware of the device. So
you will need a .hbf file, normally provided by or via  e-Mail. Please be sure to follow the
instructions, normally this works fine. The instructions are according to the Horchbox, please note that you do
not need to disconnect the battery for the Minibox – Naturally that is neither simple, nor should you open the
Minibox in any circumstance. The rest of the process is the same for both boxes.

Using the PC SW to analyze/export Data

After you remove the SD-Card from the device, you'll want to use the PC SW Horchbox.exe, to check the content of the card. Therefore, you insert the SD-Card into a card reader connected to your PC. Also, be sure to have administrator rights, before starting the PC SW. Click on Import SD-Card and normally there will be a box displayed showing how many recordings/environmental data entries are found. After all recordings are found, the main window will open, showing a list of all recordings.
Please try to play around a bit with the software, for now this is only a short description. Most of the main features are mentioned:
- To speed up, you might consider creating an image first. This will take some time, but since you might do it eventually
anyway, for backup reasons; it is recommended to do it as a first step. Then, you can open the image and
work as you did before.
- Use Freq. Analyze to get some estimations of the recording. This is definitely not a perfect algorithm, but it
does help. After the execution, you will see three additional values in the list: Freq, Energy and
calls. You may also want to check out Call View afterwards, to get a special display of the single calls (not
the recordings).
- After double-clicking on one entry in the list, you will see the time display of the recording. Use the left/right
mouse buttons to zoom and select an area to see a spectral view of the selected range. In the time display
window, try to use the shortcut keys mentioned on the buttons – this speeds things up. To set comments: Use the CTRL key and see what predefined comments are available.
- The playback of the sound will only work if you have write permissions for the directory where the
Horchbox.exe file is located. So do not start it from a CD or similar.

If you have some experience with PC's and bat analysis, you will probably find your way quite quickly through the software. Perhaps you have questions or improvement ideas – Then e-mail to  

Click here for Part 2 Of 2 of this review

Happy bat detecting!


  1. Batomania products use the same ultrasonic sensor like Batlogger from Switzerland and may be Dodotronic from Italy. This sensor loos up 60kHz sensitivity, whats make problems with determination of some species in the Myotis-Genus and also to receive Genus Rhinolophus.
    Sorry for my bad english.

  2. Thank you very much for your comment. Very interesting. For 2013, I'll be reviewing a very unique new bat detector, which has many interchangeable microphones. I'm really looking forward to it.