Thursday, October 13, 2016

Review: The M500 USB Ultrasound Microphone

Review of The M500 USB Microphone

The M500 Ultrasound Microphone, is an advanced USB device for detecting and recording the ultrasounds of bats.
It arrives from Pettersson Elektronik, doubled-boxed. The unit (and included accessories) come in a neat, white box. Along with a ZipLok-type bag, as seen in Pic below:

Also see my 'First Impressions' Post

The unit is intended to be used with a tablet PC (or equivalent) or a laptop computer.
I did a lot of testing of this unit on several types of devices; I preferred to use it with a laptop.
The newest version of this USB microphone, The M500-384 is very small and light - Yet, the M500 series is very strong at the same time (being constructed of sturdy Aluminum). 

As per Pettersson's Site, the dimensions are: "43 x 114 x 13 mm (incl microphone horn)"
To be clear, both The M500 and The M500-384 are now the same physical size.
You'll also find this unit's additional features listed on the link above.

The M500 Unboxed
The instrument's very small size, allows it to be quite flexible, in terms of which devices it may be attached to. 
It may even be used on devices as small as a cell phone. And anyone with prior experience with similar equipment, will find the unit easy to use.

I was excited about this new USB-based detector when it was first announced. I'll state, right from the start - that I really like the way it looked. I like the idea/design of the hardware itself - More specifically, the layout/design of the indicator lights (more on that later). 
And as always, I'm interested in an ultrasound recorder which can be used for both unattended, and field recording of bats.

Of course, it may also be used to record other animals / ultrasounds as well. The other pleasant surprise, is it's price: Now you'll find substantial differences in price, depending on where in the World you're located, etc. But, I've seen prices from under $400 US Dollars -to- around £465 in the UK. So, it's not as expensive as some other solutions. As always, I advise you to shop around for the best price. Check-out:
Wildlife & Countryside Services

An overview, of the very latest version of their Batsound Touch software, may be seen here.
The newly released, free version of the software has been designed to run The M500 smoothly, on almost all Windows tablets. And the M500-384, is even more flexible: It may be used on Windows an well as Linux platforms. And with different ultrasound recording software. The M500 is an ideal choice for someone who enjoys trying-out the various software packages available.

When considering the hardware which will be used with The M500: At the risk of stating the obvious, I would recommend using one with a high-power CPU, for best results.
The Batsound Touch software is very versatile, with lots of features; so there are quite a few ways in which to record sounds. More details to be added here, in the near future...

I've completed some tests and comparisons on one of the first prototypes of this unique microphone. Recording tests of The M500 revealed a very capable piece of equipment.

The M500 is lightweight and very compact. Upon plugging it in to my laptops (one running Windows 7, the other Windows 8) via USB cable, It was always recognized straight away.

I'm happy to report that The M500 can pick up bats at almost the same distances as my other top bat detectors. Some of which, have higher price tags than The M500.
And overall, it performed very well indeed! The sensitivity of this mic is wonderful!

The M500 is easy to hold and position, due to the durable & flexible USB cords that come provided.

Installation is easy, and it's easy to set-up and use: One end of the USB cable gets plugged into the M500 and the other end is plugged into your computing device.

The majority of (most commonly used) features, present themselves on your computer's screen, via The Batsound Touch interface.
The M500 (and M500-384) would be ideal units for those interested in:
Transects (esp. mobile/from a vehicle, or other forms of transport)
Unattended recording, as well as live recording (using a Netbook/small laptop PC).

When you are ready to record some bats - 
  • Plug one end of the (provided) USB cable into the back of the unit 
  • Plug the other end into an available USB port on your computing device 
  • Launch The Batsound Touch software 
  • Check the software's settings (which will be set the same as you left them) 
  • Click 'Record'
After setting up the M500 on my Asus Netbook (mini-laptop) for an evening of bat recording - I got into the habit of turning off the WLAN (and Bluetooth). The initial idea, was simply to have one less device using the resources of my wireless router (overnight).
Even though, I realize that the the impact is minimal (to say the least). It seems to not only free up more PC resources (making the Batsound software scroll even faster), but also quiets background hiss even further. This may be a helpful "trick" to try, if you're using a low-end Netbook/laptop like mine.
For example, low-end notebooks will typically have suboptimal RF shielding. 

So it appears that this is another case where the more I use this bat detector, the more I like it.

  •  Front-facing, high-quality sensor (microphone element)
  •  Simple device, robust: virtually nothing to break-off or get physically damaged.
  •  No batteries to worry about.
  • Not weather-proof.

After a very straightforward software installation; using the device is simple:
  • Customize the various recording Settings, as per your preference.
  • Click the "Record" button, and you will observe the live spectrogram display and may adjust volume, etc.
The current price of an M500 directly from Pettersson Elektronik is just under $400 (US Dollars). Price is subject to change. 
It may be ordered directly from Pettersson Elektronik; here -or- by e-mailing:  (
You may also browse their full Product List by visiting their homepage.

The simple fact is, this device can detect, and make useful (accurate) recordings of bats in flight - at impressive distances.
During my various tests, I also discovered that the recordings created by The M500 were of such high quality, that they enabled Auto ID software packages (such as Kaleidoscope) to produce more accurate identifications!
More accurate identifications, as compared to recordings from the other, high-end detectors.

The spectrograms produced are lovely. They will be added to this review, in the near future...

The M500 USB Microphone would be ideal for anyone performing passive (stationary) recordings of bats. It may also perform very well for driven transects; where the use of a laptop isn't a hindrance. 
If the computing device used is very small, and light (cell phone) - I can see The M500 being a wonderful candidate for walking transects. It would be perfect for someone recording bats from inside a home. I've tested it in this way many times, using various laptops. It's very convenient to set-up. The Aluminum enclosure is secured outside, pointing in the general direction of expected bat activity. 
You may even perform work on your laptop, while detection is in progress.

With The M500, we now have another, USB-based microphone for ultrasound recording; and it may be used across several devices. This review, is actually still a work-in-progress; and more Info and Pics will be added soon.

I'm happy to see, that there are quite a few USB-based bat recording solutions available to us now. Dodotronic has also released a new version of their Ultramic; which I am to be testing and reviewing soon.

Still to come, are reviews of The SM4BAT FS from Wildlife Acoustics, and The Batseeker 3.

Happy bat detecting!


  1. Just a quick note that there are several Android apps such as Bat Recorder and USB Bat Detector that can be used with the Pettersson M500-384 on Android smartphones and tablets that support USB OTG.

  2. Thank you Bill! - I neglected to mention that.
    Yes, the new Pettersson M500-384 will work well with the following excellent Android Apps:

    Bat Recorder -
    Which I will begin testing today; with some DIY Microphones. While I wait for the new Dodtronic USB Mic to arrive!
    And, USB Bat Detector -

    The (long overdue) M500 Review published above, should be considered a bookmark or marker for the (eventual) fully-complete Review.
    It is essentially a work-in-progress. All testing, bat recordings, etc., have been completed - But, have not been incorporated into the Review yet...

    Thank you All, for your patience!
    Happy bat detecting!

  3. Hello, first of all, congratulations for your blog, you have very good reviews of the detectors.

    I'm thinking of getting the M500 or the Ultramick 384K for active monitoring. Which one would you recommend?

    I would like to know which is better to make transects either walking or in car, quality of the recording, which is more "friendly" to use?


    1. Thank you very much. As I'm sure you've read my (private) detailed e-mail reply.
      I'll go ahead and write a very short version of it here: The answer to your question is The M500.
      Happy New Year All! Lets hope that 2017 will see lots of new detectors released!

  4. Hello,
    I would like to congratulate for the quality of your work, it is impressive, undeniably.
    I am currently using an EM3+ but I'll have to give it back somewhere in the near future. I am considering the purchase of either the M500-384 or the EMtouch. The question may have been asked quite a few times to you but I couldn't find any satisfying answer. I own an Android smartphone and an iPad mini 2. The thing is, I am not sure I am willing to trap myself in the Apple ecosystem if the EMT is not better than the M500-384. The latter surely is a lot more polyvalent than the first. However, I did not find any definite answer on which one has the best microphone.
    Therefore, considering I can afford both, which one do you reckon I should go for ?
    A very special thank you for answering this question you probably have answered many times already.

    Kind regards,


    1. Thank you very much for your comment; and the kind words. You're the first person to ask this specific (and excellent) question... Furthermore, I concur with your reasoning, etc. The simple answer is:
      The Echo Meter Touch.

      Why? ...Another, short answer:
      The built-in Classifiers.

      I will also send you a more detailed, private reply soon.

    2. I have no experience with the Echo meter touch, so can not give you a truly balanced answer. But I really like the M500-384 on an android device, together with the Bat Recorder app. The microphone is excellent (better than the Dodo250 imo), and the app is quite good as well (but has some quirks). This is my daily-use configuration now for walking transects. No other device needed. There are two drawbacks. 1) The app, while very powerful, is not very intuitive and the record button is ack. 2) the microphone needs a lot of power, draws cellphone batteries quickly, it is recommended to use a tablet with a large battery.

  5. Hi, I was wondering if anyone had a design for setting up the M500-384 for mobile (vehicular) transects?

    Also, will the M500-384 work on the EchoMeter Touch's app?


  6. I have been using an M500-384 this season instead of my EM3+ (with external capacitance microphone). The M500-384 produces lovely recordings, very sensitive and very clear, good flat response to 160kHz. But it took a while finding a host for it. The latter sees the microphone but doesn't receive any data from it. It does work nicely with an Android phone running BatRecorder but the downside is that the batteries last less than 2 hours. My final setup is to use a Sony Z3 (or similar) which has a magnetic charging port separate from the USB port. Then I can record through the USB and simultaneously provide power from a battery pack through the charging port. Wonderful - but it took the purchase of several phones to find a combination that would work.

    1. As a quick follow up, I now use a 7" Android tablet - the Asus Z380M (uses mediate internals) works very well, has very good battery life as long as you keep the screen brightness turned down, and is light and convenient to use. An excellent recording setup with Batrecorder set to a 0dB trigger threshold, although you only get the option of 5 minute recordings whereas 4 minutes is the NBMP standard.

  7. Thanks for your impressive site. For UK use, I am considering an EMT2 (Pro or basic) versus Pettersson USB 500-384. For use on walked field recordings and shortish good-weather static recordings out of rural windows or in attics. Would be used with Android on Samsung phone and tablet (EMT2 now comes in an Andriod version). Also, is the EMT2 Pro worth the extra cost over the EMT2 basic, given that the main Auto-ID software is now available for for free?

  8. Thank you for your kind words and your comment. I'll try to keep my response brief. Unfortunately, I haven't had the opportunity to test and review the new EMT2's.
    However, from my testing of the original EM Touch, I can tell you that it is a very convenient system. If you haven't seen my review of the original, you might want to have a look:
    The free Auto ID software really sets it apart from similarly priced options.

    Having said that, The Pettersson M500-384 USB Microphone is a very polished piece of Pro equipment. It has a brilliant, compact design and is built into a robust Aluminum case.
    The Pettersson is very versatile, and with it's very high sample rate (of 384kHz) is very well suited for professional use. I can tell you that the M500 excels at static recording.

    As for The EMT2 vs EMT2 Pro - Considering your intended use, I might suggest going for the EMT2, and saving yourself a bit of money.
    The additional features, and higher sampling rate of The EMT2 Pro are best suited for Pro use - High sampling rates allow experienced Pro's to examine spectrograms with "a fine-tooth comb".

    I hope this helps a bit. If you have any further questions, please don't hesitate to ask - here, or directly at: batdetectors -at-
    I'll do my best to assist.


  9. Hi. Im just wondering, what is detection range(distance) of the M500?

    1. In my review example (which was an early production unit) I noticed that the detection range was not quite as far as some other (high-end) detectors I'd tested.
      The M500 was certainly picking/recording bats from about 30-40 meters away (100+ feet distances were regularly measured). But not much further.
      On a related note, while testing 3 of Titley's mics (currently in progress) I'm using 100 feet as the testing distance.

  10. c'est surper ce que vous faites. Merci


A Quick Update Post Re: The TeensyBat 4.1 Detector

The TeensyBat site has recently released new software for The TeensyBat 4.1 bat detector. I've been using mine quite a bit lately... Th...