Friday, September 23, 2011

Review: The BatBox Griffin, From BatBox, Ltd. (UK) Part 1 Of 3

The Amazing BatBox Griffin, From BatBox, Ltd. (UK) Part 1 Of 3

I was very pleasantly surprised, to have the opportunity to review the formidable Griffin (multiple technology) bat detector; from BatBox Ltd. in England. This is their top-of-the-range model, aimed at Professionals; and advanced hobbyists. For those who are not already familiar with this unit, I urge you to visit the BatBox Web site. And, for anyone wanting more detailed information and specifications, etc.; I would strongly recommend that you download & read the User Guide. Not only will it describe the system in detail; but it also provides great recording tips, which includes specific battery recommendations. And, it basically gives you an idea of what a high-end (Top-of-the-range) bat detector is made of.

The Griffin - BatBox Ltd.'s flagship bat detecting system, is an impressive unit to behold. In the hand, you are able to perceive a bit of heft to it - But not too much. Especially when you consider what this unit offers: An advanced, self-contained bat detecting system; which automatically records to CF memory cards. In addition, it's loaded with useful features. This is not just another high-performance bat detector - It is a complete system: Which allows automatic/unattended and scheduled (timed) recordings - Where recording start & stop times are specified by the user. 

First things first: This unit is 3 complete bat detectors, in one hand-held package. Remarkable.
I've got to tell you, for starters - I've determined that the unit is very sensitive, in each of the three modes! Also, being able to easily toggle, through each of the modes (with a simple push of the 'H' button) is really nice.
The frequency division mode is excellent, just as sensitive as their Baton model - Which, as some readers may remember: I have always praised very highly! (and still do). It appears that BatBox really knows how to make a good FD system!
The heterodyne setting is nice and sensitive, the volume may be set quite high if desired (without distortion).
The time expansion system is excellent - Providing an awesome sampling rate of 705.6 kHz
And, the mixed / Binaural setting works a treat! Very nice.

Another prominent feature: Is the large blue display. It is aesthetically pleasing to the eye. Frankly, it is the loveliest display I've ever seen on a bat detector.

Some More Initial Impressions:
There is something a little different, and a bit interesting about this instrument: In that the more you use it, the more you come to appreciate it - Especially, it's features.

Things like: Being able to see your remaining battery life at a glance (displayed right on screen), having a graphical representation of your sensitivity setting (Trigger Level for recording), Real-time display of ambient light and current temperature. I happen to really like the (dynamic) bar indicator, which also indicates the point at which recording will be triggered. It reminds me of the types you see on most modern sound recorders these days.
Another one of the features that you must actually use to truly appreciate, is how a you can see just how many triggered events have occurred - By taking a glance at the display. I've found this to be a great plus. It is akin to having a live gauge of your recording progress.
In an area well populated by bats, or where bats are seen in flight: You can see a numerical representation of your recording progress.
As another example: Imagine you are using the system in it's Silent Mode (another great feature!). Whether in a static location, using it for unattended monitoring, or even walking along wooded areas in the field: The Griffin's display, will indicate the number of recordings (triggered events) that have been made. It can help you decide, if you've collected a sufficient number of recordings for the night.

The front-mounted speaker produces excellent-quality sound, which can be adjusted in fine increments, using the encoder knob. Instant playback of recordings (in the field) is yet another uncommon luxury. There are also various options available, which allow a user to configure several different methods of unattended recording.

All-in-all, a very convenient system - It's very easy to use!

Stayed tuned for Part 2 Of 3 of this review - Which will include: A lot more info, performance observations, and some sonograms.

Click here for Part 2 Of 3 of this review

Happy bat detecting!

Thursday, September 8, 2011

The Next Bat Detector To Be Reviewed: The Griffin From BatBox, Ltd. UK

Just a very quick "Heads-up" - To let you know, that the next bat detector I'll be testing and reviewing will be  The Griffin, from BatBox Ltd.

Have a look at this machine!
 ---------Display, outdoors, In the dark (Listening) Enhanced to compensate for Camera ------

Happy bat detecting!

Typical Recorders Used For Recording Bats

When using the typical, hand-held bat detectors - The ones we all know & love so much : ) A couple of items are needed, if one intends to record bats. First, of course, is a digital recorder.
The fact is, just about any device that can record sound can be used; including your laptop PC. Anything from a $15 tape recorder from RadioShack, to a top-of-the-line Sound Devices 7xx series can be used.
What I would like to share, are some recommendations that I've received, directly from a couple of bat detector Manufacturers. I love it! What could be better?!?
OK, first up, is the well known Pettersson D240X. If you just think about it for a moment... Many of you will probably remember which recorder has always been recommended (and, many times pictured with) this detector...
Yes, it is the Zoom H2 Digital Recorder! OK, that was an easy one! The D240X is pictured with the Zoom H2 recorder on a few different Web sites (in several languages!).

Next up, the BatBox Baton (from BatBox Ltd.). Here are the recommended recorders:

The Yamaha Pocketrak 2G, was initially recommended by BatBox. It's cost, was around
£175.00. (Details on the following link
But, it has been discontinued. Yamaha now has this model available: The Yamaha Pocketrak C24, which costs a bit more (at ~ $199.99 US dollars)

The Transcend MP33- 4GB USB (MP3 Player)
It costs only £35.00. Details on the following link
There's also the Transcend MP330 8BG USB (MP3 Player)
*Note:It doesn't record .wav files, but you can
convert from mp3's. It should suit both the Baton and the Duet.

Another well priced model that was recommended, is from American Audio,
called Pocket Record. It is available from CPC (code DP3028605)
at 75.00 + VAT. Details at this link. However, you will need to purchase a lead with a stereo
3.5mm plug at one end and two mono 1/4 inch jack plugs at the other end,
in order to connect it to a Baton, Duet, etc..

And, lastly, I found this "Alternative" recorder - Similar to the above. Details on the following link.

Next post, I will cover some of my digital recorder recommendations; as well as Cables, etc.

Happy bat detecting! 

Monday, September 5, 2011

Review of The SM2BAT System From Wildlife Acoustics Part 3 Of 3

Review of The SM2BAT system from Wildlife Acoustics Part 3 Of 3

Here is where I would like to share some miscellaneous sonograms and screenshots.

My usual workflow, is to:
Remove the SD card from the SM2 and check it (on PC) for recordings from the night before.
I select one WAC file at a time - Working from the largest (WAC) file to the smallest.
Convert the WAC file to WAV format using the (free) WAC2WAV converter application. The WAC2WAV software allows for a few options & variables. One of the options, is to choose (check-box to tick) is the 'Divide Output By 10' which I normally use. This provides you with wav files that are slowed down by a factor of 10. So, for example, if you were to analyze the files later with BatBox's Batscan SW- You don't have to select anything for 'Frequency and Time Conversion' - It should be left 'Off' which is the default.
Typically, the conversion will produce a lot of individual files. So, I go through each of them, using the same method above.
Recently, I've been using Audacity, to open each Wav file. It's very convenient, because it gives you a visual representation of the audio file very quickly. You can see if there are any bat calls, mixed in among the insect calls. My trees are all occupied by Katydids, etc. - I'm not complaining ('cause I like recording them also!). But, when you're focusing on bat recordings, you have to "weed them out" of course.
Since it's now mid-Summer, I usually find an abundance of my triggered recordings to be entirely of Katydids (for instance). And, I simply delete those and check the next file.
Again, using Audacity (or another audio app) which displays the 'Project' (audio track) conveniently:
What I do, is 'Select All', Amplify' and look at the recording closely, to find any area that looks like a bat call.
I also find myself listening to certain areas of the recording sometimes, just to be sure.

Adhering to the chronological order of a typical workflow, we have:
A typical wav recording (for me), displayed in Audacity:
The above shows a recording with nothing but a Katydid calling. This gives you an idea of what a recording without bats on it looks like.
I've also found, that if you're in a hurry: You can open multiple (wav) files at the same time; and just glance at each one (before closing/deleting) and you can see the bat calls (if they are present) right away. Without even having to 'Select All' and 'Amplify' for instance. It all depends on how much time you have.

This next image, below - gives you an idea of what a recording with bats looks like:
The bat calls, are represented by the "long spikes" on the right-hand-side of the spectrogram. So, as you can see, it's very easy to tell which recordings picked up bat calls - And, which didn't.
Most times, I like to select the area containing bat calls; and cut/paste/save into a new wav file. Which would look like this:
And then, you can look at/analyze the (wav) file, using the application of your choosing. Such as BatBox's Batscan software. Which will produce a sonogram like this quite easily:
BatScan just happens to be the application I go to (these days) - But again, any suitable app of your choosing may be used. For instance, the image above was made quickly, using just the default settings. But, it can be: Enlarged/zoomed-in on, to create an even more prominent "hockey stick" look to the calls.
The kHz settings can be changed, for a more accurate display and analysis.
And, (for a quick "trick") if you do select 'Time Expansion' it will automatically produce a more accurate analysis - Where you can see the calls were actually made between 40-50kHz (Big Brown Bats typically echo-locate between 25-51kHz) see below:
In the above example, you can also see a few Katydid chirps, on the lower left.
The recordings produced, using the SM2BAT are very high-quality. The 192kHz sampling rate is very nice - Crisp & clear. My next post(s) will feature some audio files you may listen to, made by the SM2BAT. And, probably some made by the Pettersson D240X; since I am still very fond of the TE recordings produced by that unit as well.
I hope that you've found this (3-Part) review of the SM2BAT informative (and hopefully, interesting as well).

Happy bat detecting!

General Thoughts About Active (handheld) Bat Detectors Part 2 of 2

General thoughts & Considerations About Bat Detectors Part 2 of 2 "Ah, but a man's reach should exceed his grasp, Or what's...