Dead Kitten windshield on my Sony PCM-M10 recorder
In June 2012 I bought my first sound recorder - a Sony PCM-M10, and immediately upon doing my first field recordings I discovered just how sensitive the recorder's built-in microphones were to even the slightest breaths of wind, and how necessary it was for me to regularly use a furry windshield. My first windshield was the Rycote Mini-Windjammer (see the photo below).
using Rycote Mini Windjammer
However, even from the outset I was disappointed at how readily I still got wind noise in the microphones. I did get used to working within that limitation, but eventually, in January 2013, I finally searched online in an attempt to find a suitably sized windshield that would be significantly more effective and enable me to work in windier conditions without my recordings being spoiled by intrusive microphone wind noise. My search turned up three possibilities, which each bore claims and indeed reviews that suggested that they might be better than what I had got - and, no doubt more than coincidentally, each of those had distinctly longer (false) fur than the Rycote that I was using. I did not include the 'official' windshield for the Sony PCM-M10, because that looked to me to be little different from the Rycote one that I already had, and reviews suggested to me that its performance would most likely be very similar.
The three windshields of interest were the Gig Wig Windscreen, Redhead Windshield and the Røde Dead Kitten* (the latter actually called 'Deadkitten' on the packaging).
* Later note, April 2016:
Time has marched on, and it is now necessary to specify that this was the original, light grey version. As noted towards the end of this report, the current black version is, unfortunately, a poorer performer, so the comparison recounted below would be of limited use now, except for anyone who manages to obtain one of the original DeadKittens.
Please note that many online traders still illustrate the DeadKitten with a photo of the original version, and the odd ones even say that it is light grey, but apparently in at least the vast majority of cases what you would actually receive from them is the new, black, version.
Because I was serious about wanting to get the best possible wind protection from a small windshield, I chose to order one of each of those three possibly superior alternatives. The Dead Kitten arrived first, not because of a cat having a conveniently timed stillbirth, but because of Amazon's very prompt delivery, and so I immediately switched to that for my next two field recording outings, and then, once the other two windshields had arrived, I set about doing a necessarily rather crude comparative indoor test, using an office fan of the type that slowly oscillates side to side. I could make a recording for each windshield and then compare the recordings not only through listening but also through examining their respective waveforms and even frequency spectra.
How they fared...
The following window clips from the WavePad sound file editor show the situation. On the left you see the waveform for the recorder facing into the 'wind', while on the right is the waveform for the 'wind' coming from the left (I turned the recorder round 90 degrees for that). Please note that these waveform representations are the sum of left and right channels, which is why you do not see significant difference between 'up' and 'down' levels for the recorder turned sideways.
I had the front grille of the fan passing about 9 inches from the front of the recorder, and then I repeated with that distance reduced to about two inches. The fan was set at maximum throughout, and the wind at the two inches distance felt to be roughly equivalent to a 'fresh' breeze (force 5 on the Beaufort scale). Pity I couldn't get a stronger blast from it! This was thus not a very challenging test. Also, the test was particularly crude because the fan noise actually made the microphone wind noise quite difficult to hear except then the recorder had no windshield at all.
The recorder was set at what was for me an optimal level for the majority of my natural soundscapes, allowing plenty of headroom to avoid possible clipping, and allowing naturally quiet soundscapes to indeed be quiet - number 3 on the recording level setting, with sensitivity set to High.
As I had already experienced, any wind noise in the microphones, even if not causing 'clipping' at all, always had an unpleasant and intrusive 'blocky', angular, jarring quality, quite different from the sound of the wind in one's ears, and this definitely needed elimination as it was. Here, the 'wind' has caused major and consistent overloading and thus clipping of the waveform. I did not bother to repeat this recording closer to the fan, as the point had already been well made and no new information would have been gained.
Rycote Mini Windjammer
Gig Wig Windscreen
Røde Dead Kitten
The first clear observation is that ALL of these windshields succeeded in cutting out the worst of the wind noise in the microphones. However, there is something here that the waveforms do not show you, and that is, what the wind noise actually sounds like. In fact the use of any furry windshield softens the 'outline' of what wind noise does come through, so that it has a gentler quality, much more like the sound of the wind in your ears. As I found out in many of my own recordings, particularly where the wind is an intended part of the recording, once any microphone wind noise has been softened in its quality it can be an acceptable and even enhancing addition to the recording, provided that it does not come through so strongly as to be disruptive to the particular soundscape.
It appears that, with the lighter 'wind' at about 9 inches from front grille of the fan, the Gig Wig and Rycote windshields were very similar to each other in performance, though the Gig Wig performing slightly worse for wind coming from straight ahead and slightly better for wind coming from the side.
The Redhead windshield, as would be expected from its large, omnidirectional-looking 'mop' of false fur, was distinctly more effective than either of those two, and, unsurprisingly, particularly more effective for wind coming from the side. That tallies with another observation, which I mention further below concerning practical usability.
The Dead Kitten is the clear winner here, with consistent lowest wind noise from front and side. Again this is no surprise, because it has the most substantial-seeming 'mop' of false fur
...So now let us look at what happens when I attempt to give the windshields a controlled stronger blast.
Rycote Mini Windjammer - close
Gig Wig Windscreen - close
Gig Wig Windscreen - close (repeat)
Redhead Windshield - close
Røde Dead Kitten - close
As already noted, I sought to have the front of the recorder something like two inches from the front grill of the fan. However, this was not possible to measure exactly, and it is clear that at this closeness the inevitable small variations in placement were having a big effect on what the poor long-suffering microphones picked up. Also, at this closeness the hum from the fan was really obtrusive, and in all these close recordings that hum and the rushing of the 'wind' (i.e., not microphone wind noise, which is a heavy and very irregular rumble / 'drumming') were the loudest components of the sound that I could hear, so ALL the windshields were doing a pretty good job, considering. However, it was still possible to differentiate usefully between the different windshields.
It needs to be remembered that when you are out in the open in a wind, you do not have close fan noise drowning out the microphone wind noise, so that what may sound like very slight differences here, rather lost in the close fan noise, would generally represent very important differences in real life recording situations. ...So, what useful information can we gain from these 'close' recordings? -- Actually, more than might first appear.
At first glance we can be struck by the differences that presumably have resulted from variations in placement, and thus get distracted from the important observations. The fan noise fluctuates in strength in a cyclical fashion as you hear it from any particular position, and this appears to show particularly strongly for the closest placings of the front of the recorder to the fan. So, a big fluctuation in the overall sound level does NOT in itself represent more microphone wind noise. What we actually want to look for is the degree of spikiness of the waveform. The point here is that the 'wind' from the fan is naturally turbulent, and so the microphone wind noise would produce a very spiky waveform in the recording, whereas the fan noise itself and rushing sound of the general 'wind' is much smoother and would not be producing much or even any at all really noticeable irregular transient spikes.
So, where do we see the greatest spikiness, i.e., relative to the basic sound level of the fan noise? -- As we could reasonably expect now, it is in the waveforms for the Rycote and the Gig Wig. Indeed, the spikiness is so dense that it almost completely obliterates the fluctuations in the basic fan noise. It is not surprising that the microphone 'wind' noise is not fluctuating that much at this very close distance, because the 'beam' of air from the fan would be fairly wide, and at this close distance the recorder would never be out of it. This was also borne out in listening to the close recordings, in which the wind noise, if audible at all, was pretty constant, whereas, as I say, the fan noise was somewhat fluctuating in intensity.
There is one bizarre-looking exception in the case of the first close recording of the Gig Wig turned sideways. Actually I repeated that recording only because of a slight mix-up, in which I thought that one recording had got missed out when it actually hadn't. The very anomalous sideways waveform graph of that first recording suggests that I must have inadvertently placed the recorder even closer to the fan at that point, and so picked up the fan noise very strongly, complete with its fluctuations. However, you will note that it is bristling throughout with a constant spikiness caused by the microphone wind noise.
The Redhead windscreen comes out better, with smaller spikiness from the microphone 'wind' noise. You can see more of the regular fluctuations of the basic fan noise.
Again, it is the Dead Kitten that comes out on top, with the smallest spikiness. That this represents lowest microphone 'wind' noise was corroborated by a careful listening to the recording. This was the one in which I could not be sure that I was hearing microphone 'wind' noise at all. Because of the din from the fan at that closeness, I cannot put it more strongly than that. For all I know, there could have been little or no such noise in that recording, though I assume that the slight roughness of the waveform outline created by the fan noise does represent a small amount of microphone 'wind' noise.
In the first of my two (so far) field recording sessions with the Dead Kitten there was a breeze that I estimated as 'light to moderate' (force 3 to 4 on the Beaufort scale) coming from the left, which caused a fair amount of clipping (red LEDs flashing) when I did a recording test without the windshield, but with the Dead Kitten in use, on subsequent playback at home I could hear no microphone wind noise at all against the sea sounds that I had recorded. The second field recording session doesn't count, because it had almost no wind. I look forward to trying the Dead Kitten in stronger winds, and will report here what I eventually find to be my acceptable maximum wind strength for respective different types of subject / soundscape.
These results were underlined by examination of the real-time frequency spectrum graphs in Voxengo's Span plug-in in WavePad. The 'wind' in the microphones caused a broad rise in the 'boomy' lower frequency range, and the size of this corresponded with the degree of spikiness that one could see in the waveform - the Dead Kitten recording having almost no obvious rise or 'hill' in that frequency range.
Muffling of the sound
ALL furry windshields would very slightly lower the overall sound volume and selectively reduce the level of higher frequencies ('muffle' the sound in everyday parlance), whether or not that sound loss / alteration is enough to be readily detectable. That must be so, no matter that apparently almost nobody considers likely muffling by their windshields and applies any correction for that to their recordings. The question is, to what extent was this happening for me. Here I ran into rather a puzzler.
At a very early stage after I bought the recorder I did a test field recording (using the sound of a rain shower actually) with and without the Rycote Mini Windjammer. Examination of the real-time frequency spectrum graph of relevant parts of the recording in Voxengo's Span plug-in in WavePad showed a small but distinct attenuation of the higher frequencies, and, through some trial and error I succeeded in creating in WavePad a graphical EQ profile to correct that slight muffling - i.e., it restored the frequency spectrum graph to indistinguishable from the graph without the windshield. I then applied that correction profile to all further recordings I made with the Rycote. All well and good.
Then, eventually, along came the Dead Kitten. As it had a denser mop of much longer false fur, I quite reasonably expected that it would muffle the sound more, and so on my first field recording session with it I started one sea recording without it, and then after about two minutes I put it on. Result: horrendous microphone wind noise without it and none detectable with it, but NO detectable difference in the frequency spectrum graph. This seemed difficult to accept, but there was the living evidence! So I did not apply any EQ correction to the recordings made using the Dead Kitten. Just to make sure about this, on my next field recording outing I did another 'with' and 'without' test on a sea recording, and again I got no detectable difference between 'with' and 'without' in the frequency spectrum graph.
And then along came the other two windshields and my indoors comparative test using the fan. This was not altogether an ideal type of sound for testing slight muffling, for a high white noise component in the recorded sound is really needed for properly detecting muffling. Anyway, what I found was that in those recordings the real-time frequency spectrum graphs showed a slight muffling for ALL the windshields as compared with the recording with no windshield. And, what's more, I could not detect any significant difference between the muffling of any of the windshields.
On the face of it, then, I could improve recordings made with ANY of those windshields by applying a graphical EQ profile that I could work out, which would be reasonably correct for any of them; presumably it would be more or less what I had already worked out for the Rycote. However, my field recording tests with more 'white noisy' sounds had come out differently for the Rycote and the Dead Kitten, and so I am left puzzled and not altogether sure what to do about that.
Ultimately my own field recording tests will have to rule, but the indoor test results at least indicated a definite advisability of doing 'with' and 'without' tests a few times more for the Dead Kitten before I finally set my EQ or no-EQ policy for recordings made with it.
Please see the Follow-up section further below for a major update on this.
Other factors to consider when choosing between these windshields
If you read other people's reviews of particular small windshields, you will find that each windshield elicits at least some complaints about its being difficult to get onto the recorder - at least, as concerns the Sony PCM-M10. Unfortunately this seems to be a fact of life. If a windshield doesn't have reasonably strong elastic, it would be liable to slip off at unfortunate moments. However, I found that there were significant differences between these particular windshields with regard to practical ease of use. One problem is the neat and so-compact shape of the PCM-M10, with the microphones recessed within the two quite rounded front corners of the rectangular, mobile-phone-shaped little box. Once you've struggled and eventually got the windshield's elastic securely over the front end of the recorder, (a) if you were not very careful you could easily have inadvertently got the recorder's microphone sensitivity switch moved from 'high' to 'low' (that happened for me, and I wondered for a long time why I was getting such low levels in my recordings), and (b) things that you need to see on the face of the recorder will almost certainly be at least partly hidden.
For a start, with all these windshields you can say 'goodbye' to being able to see the useful peak level indicator LEDs of the PCM-M10, so you will not get an easily visible warning of clipping. If you try to render them visible, most likely the windshield will pop off.
Worst offender was the Redhead. That impressive and cuddly-looking mop of false fur all round made it really difficult to use. That 'fur' actually continues right round the edge of the elastic, with the result that, to start with, it is the devil's own job even to locate the opening that you are then going to need to stretch over the recorder's front. Then, not only is the elastic tight, with little 'give' at all beyond the width of the PCM-M10 (for which this example was supposed to be made), but the fur all over the elastic makes it difficult to hold while you are trying to stretch the opening, so I found it tending to slip out of my grip and often drop to the floor, so I would then have to start all over again. And then, when I did get it on, that fur all over the elastic obscured about half the LCD panel too. I was able to push that back a little, and then could just see the lower of the LCD horizontal level meters.
So, although I really wanted to keep the Redhead as a 'second string' backup in case of any loss or failure of the Dead Kitten, actually I would not want to use it at all. If I have such a struggle with it indoors, it would be a real devil in a real recording situation where I want to get the recording started quickly - and the obscuring of so much of the display window is quite unacceptable.
The Gig Wig has elastic reasonably free from 'fur' interference and so was much easier to put on - though still difficult in a tiresome sort of way, because it is incredibly shallow, and has only just enough depth to accommodate sufficient of the front end of the PCM-M10 for it to stay on securely. At least, once it is on, the 'fur' does not obscure the display window in the forceful way that the Redhead does. It does tend to flop over most of it, but you can easily hold or gently blow it out of the way, and with care you can then see virtually all of the display window - but of course still not the handy peak level LEDs.
The Dead Kitten was easiest to put on, because (a) its opening was easy to find, (b) its long fur was not all wrapped around the elastic, and (c) the elastic, while quite strong enough to keep the windshield firmly in place, had much more additional 'give' than the other three, so that it could be more easily stretched over the front of the PCM-M10 and indeed would be able to fit quite a wide range of small recorders and microphones. Its more generous depth also helps there. Significantly, the Dead Kitten doesn't come in sizes for different models, so many people who theoretically would like to use it do not do so because they do not realize that it would fit their particular equipment (Røde appear not to give helpful information about that in their sales blurb for that windshield).
However, with its thick mop of long 'fur', it was the second most troublesome with regard to obscuring the display window.
The Rycote, with its much shorter 'fur', was the clear winner with regard to visibility of the display window, though, as already noted, no windscreen that has an elasticated fitting over the front of the recorder could avoid covering the PCM-M10's peak level LEDs. Its elastic was particularly strong, making it fairly difficult to put on, but this was mitigated by its elastic being easy to hold onto while stretching it, with no 'fur' interference.
There was thus no one clear winner in the practical usability stakes, though the Redhead was the clear loser.
I did not set out here to write a 'professional' or completely rigorous comparison between these windshields, but just to enable others to benefit from the little bit of research and somewhat crude comparison work that I did purely for myself. On the basis of my findings, I am happy to settle for the Røde Dead Kitten as my windshield of choice for normal purposes (and to genteelly tiptoe round the inevitable jokes about putrid smells and maggots!). Really the one nuisance about it for me is my getting only a partial view of the recorder's display window - a nuisance that I am resigned to have to live with. However, for some of my recordings, especially for my Wind Chimes in the Wild project, a certain amount of (softened) microphone wind noise at times tends to be an enhancement, and if I find that the Dead Kitten is too effective in cutting microphone wind noise I would be inclined to revert to the Rycote Mini Windjammer for those particular sessions in order to get a more realistic level of microphone wind noise (i.e.,'realistic' in the sense of being like the wind in one's ears in such a situation). The Dead Kitten would still remain my regular windshield, however - i.e., unless at any time I came across a still better one!
I am currently puzzled by the discrepancy I found between indoor and field recording tests on the muffling effects of the Dead Kitten. As I say, ultimately, whatever my indoor tests showed, and however unlikely the results of my field recording tests appear to be, I would have no sensible option other than to follow the indications of my field recording tests, which so far have shown no detectable muffling effect at all from the Dead Kitten - which, if true, would be a plus point in that I would have no need to apply a corrective EQ profile to my recordings.
Although the Rycote more or less tied with the Gig Wig as being least effective for its primary purpose, both windshields still did a very reasonable job in modest breezes, though in anything more than a light breeze we are talking of reduction rather than effective elimination (though of course the reduced wind noise might be hidden by the actual subject of the recording and thus appear subjectively to be eliminated). Of those two windshields I would definitely go for the Rycote, because (a) it seems better made, (b) it allows better visibility of the PCM-M10's display window, and (c) I am a bit concerned about the sparseness of the fur in the Gig Wig; I suspect that the latter would not need to shed much fur or get much matting at all before its effectiveness is significantly compromised.
Although the Redhead windshield is almost as effective as the Dead Kitten, I really don't want to use it at all, because of the difficulty of getting it onto the recorder, and the way it obscures so much of the latter's display window. I will thus not use it for the second PCM-M10 recorder that I now have, and indeed have ordered a second Dead Kitten.
Please note that all the above references to the DeadKitten are referring to the original, light grey version. Unfortunately, that has been replaced by a black version, which has floppier fur and performs significantly worse for wind noise protection.
Having published this review here, I e-mailed the manufacturers of all four windshields to draw their attention to it so that they could be prompted / assisted by the above observations to improve their products. The Gig Wig manufacturer (an independent small business trading through eBay) said they would endeavour to produce an improved product on the basis of the points I had raised (and indeed their own observations, for they were already aware of some issues that they were wanting to address), and Rycote said they were already introducing a notionally improved version of their Mini Windjammer, the extant version of which they had already recognised as needing improvement in its wind-stopping effectiveness, and offered to send me an example to test - an offer I accepted. Røde thanked me and were pleased that I had effectively confirmed that theirs was the best ()*, but nothing was said about possible improvement of their products (i.e., improvement upon how they are at the moment). Redhead did not respond.
* Sorry to say, it would no longer be so. As noted further below, the new, black version of the DeadKitten is a significantly poorer performer than the original.
Rycote Mini Windjammer, new version
The day after I had the response from Rycote I received the new-version Mini Windjammer that they had sent me to try out. I carried out basically the same test that forms the body of the above review, except that I tested just Rycote Mini Windjammer versions 1 and 2 and the Røde Dead Kitten, and didn't bother to turn them sideways.
The new version Mini Windjammer actually looked to me as though it would perform much better. Although its fur was still relatively short, it was larger because of more space inside, and it also had a lining consisting of a thin layer of open-cell foam. Surely this would now come close to Dead Kitten performance!
Sadly, despite all the thought and good work put in by the Rycote people, I found only a very small improvement in performance compared with the original version that I tested. That left the Dead Kitten still considerably ahead in performance, making the difference between the two Mini Windjammer versions look almost insignificant. On that basis, it would not be good use of my time to take out the new-version Rycote model to try out on a field recording session, as I had thought I would be doing.
...And so the situation remained till July 2015, when I had cause to contact Rycote again - see the 2015 follow-up further below.
Solving the Dead Kitten mystery!
On 6th February 2013, on one of my wind chimes field recording outings, I finished up doing a series of chimes recordings right beside the River Teign, which latter had given only a very quiet background sound in my previous recordings, which had all been from spots near the top of the north side of the valley. Just as I was about to pack up I had a sudden impulse to do another test with / without the Røde Dead Kitten to see if I could recognise any muffling effect from it - for I had right beside me a weir with fish ladder, with a lot of water flowing, and it was making a very powerful constant white noise sort of sound*. That I did, and the result turned out to be extremely illuminating.
* Okay, just to quieten any nitpickers - I do deliberately say 'sort of', because the sound would be technically regarded as 'pink noise' rather than white noise. This sound has a much more gentle high frequency component than actual white noise, even though having the same sort of sound in other respects. Genuine white noise seems to be a rare phenomenon in nature; maybe a volcanic steam jet could get close.
This time I could see at once in the first part of the recording that the real-time frequency spectrum graph was more high-treble-attenuated than in the second part, after I'd whipped the Dead Kitten off the recorder and let it run another minute. Not only that, but even with my computer speakers I could hear a clear and unequivocal difference. Without the windshield, the 'white noise' had a beautiful smooth light 'sheen' to it, which was not audible from the part of the recording made with the windshield.
Brilliant! - So then I set to in Voxengo's Span real-time frequency spectrum analyser plug-in to work out a correction profile that I could then use in WavePad to correct all my recordings so far made with the Dead Kitten. - Well, except that there turned out to be a problem. Yes, I got the graphical EQ graph curve set to make the Dead Kitten affected part of the Teign weir recording have the same shaped frequency spectrum curve as the part of that recording without said dead kitten - but yet the sound was NOT the same! The restored-from-muffled was certainly brighter and clearer than before my processing, but where was that beautiful smooth light sheen to the sound? It was replaced by a bright and rather aggressive roughness or 'chatter' to the 'top edge' of the sound. No matter how I tinkered with the graphic EQ curve, I could not get the restored sound to come out any better.
Did this mean, then, that I needed to use different software for the EQ process? - To find out, I then set up the same graphic EQ in Audacity, and found that I had exactly the same problem*. I also came to notice why the restored sound had that rough top edge, and it was clearly the Dead Kitten and not my sound-file editing software that was doing it. The part of the original Teign weir recording made with the Dead Kitten, together with all EQ'd versions of it, had a slightly rougher-looking frequency spectrum curve (more pronounced and irregular micro-peaks), even though it had broadly the same shape overall, and this roughness was presumably associated with the harsher sound of the EQ'd versions of the Dead Kitten part of the recording.
* Actually, one very positive thing here was that I found that I could now set up graphic EQ curves effectively in Audacity, which I had failed at (to my satisfaction) some years before, and this was great because that program allows you to save such custom profiles for easy re-use, whereas WavePad doesn't, so one often has to go through purgatory accurately re-entering the required nodes on the EQ graph.
I established by careful observation of the frequency spectrum graph while playing the recording, that the additional roughness was little or nothing to do with any sort of artefact having been introduced by the EQ. What appeared to be happening was that the Dead Kitten was exaggerating various micro-peaks in the frequency spectrum - particularly by exaggerating the amplitude of transient tiny high-frequency details in the overall continuous sound.
I then spent parts of a sleepless night with 'overactive mind', working out how it could be that the Dead Kitten was introducing that distortion into that recording. The speculative explanation that I arrived at was as follows.
The 'fur' or other protective material that is the basis of a windshield inevitably contains a myriad 'micro-resonance' points within the interstices between the 'fur' fibres or in, say, cavities in foam. Those interstices are far too tiny for any frequencies other than distinctly high ones to resonate in them, so only high to (particularly) very high frequencies can be affected, but what looks to be happening is that the 'micro-resonances' that occur while sound-waves are making their way through the windshield actually obstruct the passage of those frequencies that are resonating at any particular point. Thus, with a whole mass of micro-resonances occurring for high frequencies, those very frequencies do not pass so readily through the windshield and thus are attenuated in the recording.
This is nothing specific at all to the Dead Kitten; it is inherent in any sort of material that would be used to reduce microphone wind noise and maintain acoustic transparency. Unfortunately, the denser or/and thicker the barrier, the more micro-resonance points would be present, and thus the more effective windshields could reasonably be expected to be the worst culprits with regard to muffling. (Please remember that I am speculating here, not stating categorical fact!)
So, how does the exaggeration of micro-peaks in the sound's frequency spectrum come about? -- My speculation here is that the greatest micro-resonance effect occurs where a sound is continuous and with very little variation, both overall and within its detailed 'substance'. Thus significant changes of / within the sound tend to dispel or at least minimize those micro-resonances. One effect of this is that different types of sound would be muffled to different extents. However, there would also be a micro-scale effect of this phenomenon, in that if there are small transient details within even a continuous sound, such as was the case in the sound of the River Teign weir that I recorded, certain of them would 'stand out from the crowd' sufficiently to 'puncture' a 'micro-resonance cell', causing a momentary breakthrough of that frequency as the obstruction to it just there has suddenly weakened or collapsed. This 'threshold' or 'gate' effect would very nicely explain what I was observing - i.e., the increased raggedness of the real-time frequency spectrum graph.
Not only that, but it would account for another part of the apparent mystery - just why my previous field tests had failed to show any muffling at all caused by the Dead Kitten. It just happens that both those tests were carried out while I was recording some very mobile sea interacting 'interestingly' with rugged Cornish cliffs. In other words, although the sound had a big 'white noise' component, it was not a constant and more or less unchanging sound, but was full of 'life' and movement (which also means that visual examination of frequency spectrum graphs of such a sound would not readily reveal small degrees of muffling). It is not that there wouldn't have been some muffling, because some parts of the sound would have been smoother and more constant than others, but the sounds that one would most listen to are the very obviously changing ones, which are actually those that would tend to keep breaking down the relevant 'micro-resonance cells' in the windshield and thus would get minimal or even no muffling.
So, what was I to do about this? Clearly there could be no way for me to eliminate the increased raggedness of the HF part of a sound's frequency spectrum, except by not using a windshield at all - a complete no-go with the internal microphones of the Sony PCM-M10 and no doubt most other small portable recorders. So, if I am to continue using a windshield, unfortunately I have to accept that the recorded sound will have a certain HF roughness or raggedness that was not present to that degree in the original sound. But then, what to do about the muffling, as this appears to be not a constant at all, but something that varies not only between different recordings but also even between different simultaneous aspects of one soundscape at a particular moment?
My pragmatic answer here is to use a sort of 'happy medium' graphic EQ profile on all my recordings taken with a windshield, being aware that then some sounds would be a little over-bright while others would still not be quite bright and clear enough. I'd already worked out a corrective profile for the overall treble attenuation caused by the Dead Kitten, but that would be Draconian for my recordings generally, in which 'mobile' sounds are generally the main object of attention. My corrective profile for the Teign weir recording rose to +6dB at 10KHz, +8dB at 12KHz, then level up to 15KHz, then rising to +9dB at 20KHz. So, what I tried was to process the contents of a copy of the first two recordings from my 'Wind Chimes in a Gale' day with that profile, and another copy of those files with a version of that EQ profile with half the rate of increase with frequency, so that the maximum increase was just 4.5dB, and burn them to CD and carry out a listening test to see which version sounded to be the most 'natural' in sound - I already having burned a CD of those recordings without EQ adjustment.
The result of that listening test was clear cut - the version that had used the 'happy medium' EQ profile standing out really satisfyingly as sounding 'natural' and as accurate as I would be likely ever to get. The full EQ profile definitely caused over-brightness, while without the EQ I could hear that the treble had a sort-of 'hooded' quality because of the particular 'shape' of the attenuation of its higher reaches.
I have therefore gone back to all my recordings made with the Dead Kitten and applied the 'happy medium' EQ to them. This had to be done individually to each file - not as a batch process - to ensure that the processing didn't cause clipping anywhere. Spot listening tests have all shown improvements - even in the case of the sea recordings where I had previously failed to demonstrate Dead Kitten muffling!
Just how effective is the Dead Kitten?
I had wondered if the Dead Kitten would enable me to record in quite strong winds. I did not risk having a wasted recording through actually recording fully exposed to a gale, but inevitably during the winter of 2013 I had various field recording sessions where the recorder did get hit by various quite strong gusts. In the event I found that wind noise did come through, and the really strong gusts came out quite loud in terms of the microphone wind noise. However, generally that noise was very nicely smoothed, so for the most part it enhanced my soundscape recordings rather than spoiling them, for I wanted the wind to be heard. While microphone wind noise generally sounds horrible in recordings played back through boomy speaker systems, I find that this particular microphone wind noise, attenuated by the Dead Kitten, sounds really 'natural' and often quite beautiful when played through my genuine hi-fi speakers, giving a really vivid impression of the wind, without any impression of a disruptive intrusion upon the recording. This was the case to a fair extent with the Rycote Mini Windjammer, but the Dead Kitten has simply made it possible for me to work with somewhat stronger winds without the microphone wind noise becoming unacceptable.
However, for recordings where you do not want to hear the wind at all, then a completely different system would be required in anything other than a really quite gentle breeze.
Please note, however, that all the above observations refer only to the light grey original version of the DeadKitten. As noted further below, I have now found to my disgust that the new, black version of the DeadKitten is poorer-performing and is now not particularly likely to be a clear winner in any contest.
2015 Follow-up - the Rycote Mini Windjammer isn't dead yet!
So, I'd been sitting on my laurels (okay, rather stinky dead kittens, then!) from early 2013 onwards, fairly smug that I'd probably got the best possible windshield for my recorders (in early 2013 I'd purchased an additional recorder of the same model). That didn't mean that I was able to record satisfactorily in significantly windy conditions, however, but really meant that I'd just assumed that I'd got the best possible windshield to fit such a small portable recorder at a price that I could reasonably afford. In fact I did have the odd recordings marred or occasionally ruined by wind, and, particularly importantly, having a good idea of what I couldn't get away with, I was often not making recordings that I really wanted to, because I was sure they wouldn't be worth recording without something more in the nature of a Blimp, which would be both out of my price range and massively too big for me to take out with me on my hikes.
Then, in mid-2015, on one of my outings I lost one of my DeadKittens. Fortunately I had a spare, so I was able to continue using both recorders, but I did need to replace that spare. Then I found to my disgust that Røde had gone over to any colour that one wants for the DeadKitten, as long as it's BLACK! It turned out that they had responded to some user requests for that model to be black to make it inconspicuous. Unfortunately Røde hadn't taken into account that other recordists would actually want light coloured windshields, to make their recorder / microphone conspicuous! I'd been finding the conspicuousness of the DeadKitten quite important, assisting me in retrieving recorders that I'd placed in rough / complex terrain, even sometimes in the dark. That conspicuousness also worked well for photos that I took of recording situations, which I could then use in CD artwork.
I started a new online search for alternative makes of windshield, which might be at least as good as the DeadKitten, and that reminded me of my correspondence with the Rycote people, who had seemed very keen to do what they reasonably could to assist. Indeed, the last e-mail I'd had from them invited me to come back to them in the future if at any time I wished to discuss further windshield requirements with them. So, I contacted them again.
The response was immediate and extremely positive, with a clear intention of theirs to provide me with a custom Mini Windjammer with enhancements, to try out, and to work on this till, if at all possible, they had at least equalled the Dead Kitten performance for me. It is clear from their correspondence that they regard their Mini Windjammer as very much a compromise between convenience and effectiveness, for longer fur would mean a more bulky and conspicuous 'mop' over the recorder / microphone.
They have now already (same day as my contacting them), as a first step, arranged to have a grey, longer-fur Mini Windjammer made for me, with an additional wind protection layer inside. Then, when I've tested that alongside the DeadKitten, if its performance is still not fully 'there', they have certain other enhancements they can add for me to try out, till we do get to at least as effective as the DeadKitten.
I'm at least hopeful that their first effort will approximate to DeadKitten performance, and then perhaps, with a little nudging, they would see how far they can reasonably go to actually exceed that, to arrive at an 'elite' version of the Mini Windjammer that is actually significantly superior to the DeadKitten. Easy to say, of course, but it may well not be workable to go that far because of the various trade-offs (especially increased muffling of the sound) that would come through making windshields more effective in reducing wind noise. It would be simpler with the larger windshields that are made for larger equipment, but it might be rather a tall order for something to fit a lowly little Sony PCM-M10!
I will report here on how this develops, but I can say right now that the Rycote people are showing up as seriously good guys, and I think something pretty positive is going to come out of this.
I tried three successive trial versions of the Rycote Mini Windjammer, which did get a little better, though still not fully up to DeadKitten standard of protection, but have to admit having rather given up on that, because clearly the Rycote people were very busy with their regular work, so I kept finding myself waiting for weeks and then having to chase up to remind them that I was still awaiting the promised next improved version. So, I finally gave in and reluctantly purchased a couple of the new-version black DeadKittens, to keep as my spares.
End of story? - No, by no means! In early 2016 a rarely manifesting intermittent fault in one of my PCM-M10 recorders lost me otherwise excellent recordings on two successive sessions, and so, that being well outside any warranty, I chose not only to order another (from end-of-line stock, for the model had insanely been discontinued despite its popularity) but also to bite the bullet and order the recorder's prestige 'big brother' - indeed one of Sony's real flagship products, the PCM-D100. That is bigger and markedly heavier than the PCM-M10, and I found that my old DeadKittens couldn't fit on it but the new ones had a much more stretchy elastic and could easily do so. The furry windshield bundled with the recorder was unusable, being a good fit on the M10 but virtually impossible to get onto the D100. So, I tried using the D100 with the new DeadKitten.
I then ran into the problem of the extreme wind sensitivity of the D100's, and found that even with the DeadKitten, I could not usefully record with it in many situations where I could use the M10, just because of this wind sensitivity. I then did a series of indoor fan tests to compare windshields, and discovered that the new DeadKitten, which I hadn't yet tried out on the M10 recorders, was significantly poorer-performing than the old version. This was actually no surprise, because the new DeadKitten's fur was softer and more floppy, and certainly didn't look to be very protective when getting even just a force 3 breeze. I think actually that the black DeadKitten's performance on the D100 was made still poorer by the extent to which the shield's fabric was stretched by the D100, which latter I'm sure is larger than the DeadKitten was ever designed for.
So, I got in touch with my dealer, who got in touch with Rycote to see if they could come up with a really effective solution for the D100. In the meantime, just as a backup, I ordered one of Rycote's current production Mini Windjammers for that model, because it looked to be a significantly larger and more substantial affair than the Mini Windjammer for the M10, so my guess was that it would perform better than an over-stretched current-version DeadKitten on the D100, even though most likely not enabling me to get good recordings in all situations where I could do so with the M10 and original-version DeadKitten. I also ordered a Gutmann windshield for the D100, with the intention of choosing the better of those to use as my regular until such time as a more effective solution was found.
Unfortunately, neither of the specially ordered windshields appeared to be good enough for me to use instead of the new-style DeadKitten. The Rycote Mini Windjammer for the D100 did fit properly and was reasonably easy to get on - but the apparent Bad News was that my fan test showed it to be significantly less effective than the new version of the DeadKitten - about 4-5dB poorer, the recording level indicators reading 'Over' even at a 'wind' strength of just 2-3 Bft, and even with the 'wind' coming from the side rather than front. That appeared to mean that, for my purposes, it was not worth even attempting to use that windshield - £30 down the drain just like that! The Gutmann windshield was pretty well as tight a 'fit' as the Sony one, and thus unusable for all practical purposes. I did manage to get it on after a few minutes of severe struggle, and then my fan test showed it to be nearly as effective as the new-style DeadKitten, so that in other words it was useless to me anyway because the DeadKitten, itself inadequate for such a recorder with such insanely wind-sensitive microphones, was clearly what I would have to use until / unless a significantly better solution could be found.
However, later on I did a comparative field test of the Rycote and found that it performed just as well as the Movo WS-R30 furry windshield, which I had by then established to be of similar performance to the original version of the Røde DeadKitten, and much easier to put on - so I could use it after all on one recorder, along with that Movo windshield on the second one, until I found a solution that was really adequate.
I understand that at the moment Rycote is investigating the possibility of an altogether more effective solution for such a wind-sensitive hand-held size recorder, by constructing some sort of windshield - probably some sort of case enclosing much of the recorder - made out of the material used for their Super Softie shields. The material is non-furry, and is claimed to give better wind protection plus better acoustic transparency than the various furry windshields - but it's quite a bit more expensive, and I think it would be more of a challenge for a manufacturer to work into any sort of windshield for a portable recorder, through being much stiffer and less elastic than standard furry windshield material, so such a windshield may not be all that practical to produce. Time will tell...
The great solution comes up at last - after a most deceptive false dawn
In June 2016 I tried a Movo non-furry windshield (WST-R30) of the right size for the PCM-D100, which windshield is inadequate on its own, with a custom-made Windcut furry windshield fitted over it. Windcut appears to be a small one-person business, and their website has aspects that make one wonder about its genuineness, but I noted that their 'furries' had had some good user reviews and comments, especially in forums, so I thought I would give them a try, as their pricing is comparatively very low, even for custom windshields, and I wouldn't have lost too much if it didn't work out. In the event, after some initial trial and error with regard to design, they arrived at a design that works extremely well, and without charging me extra for the work involved.
Indeed, even on its own the Windcut showed up on my fan test as having at least as good
performance as the original version of the Røde DeadKitten, and
the combination of the Windcut and the Movo at last got me overall wind sensitivity for
my D100 approaching though still not fully as good as the level of the PCM-M10 with Røde DeadKitten. I worked out
a treble EQ curve to compensate for the inevitable muffling of the sound, and was rather
surprised to find that it was no more severe than the curves I worked out for other furry
windshields on their own, such as the Røde DeadKitten and a Movo furry windshield. On
that basis I was recommending that design of Windcut furry windshield over any other makes
I knew, even where one intended to use it on its own.
However, there turned out to be a catch, and I freely admit to a rather mortifying mental block of mine, by which I continued making recordings with the Movo / Windcut combination right through into late February 2017 before I actually woke up and recognised that the rather screamy and abrasive treble quality of all sea recordings I'd made with that windshield combination was a problem that I needed to investigate. What I then found was that that design of Movo windshield is, frankly, crap. Yes, CRAP! The unorthodox semi-rigid squared design of those Movo windshields causes an internal resonance that gives the treble a significant peak centred something around 5 KHz, and a lesser one a bit higher, both of which need to be corrected for in addition to the inevitable overall muffling. Although I did learn to do a good job of restoring the recordings' frequency spectrum and getting superlative sound quality, that was very time-consuming work, which had to be done on an individual basis for each recording session for each recorder - i.e., there was a specific reason why just storing a single correction curve and using it on further recordings couldn't work. It had thus become urgent matter, to find a superior alternative.
My probably final solution comes up at last
I therefore decided to try Windcut furry over Windcut furry, and ordered custom ones of exactly the same design as the outer but of the required smaller size, to be used as the 'inner'. I was concerned that the muffling could be excessive with this arrangement, so I wasn't at all sure that this would be really workable.
Actually it took quite some time and persistence on my part, because Windcut ran into a practical problem in trying to do the same design as for my outer Windcut furries at the much smaller scale to fit onto the recorder directly. This issue was eventually overcome, after my trying out a couple of prototypes - and it really does give significantly the best wind protection I've yet had for the D100. To my surprise, the muffling was no more than what I'd had with the Windcut outer over Movo inner, and, as expected, there was no issue with any added treble peaks / troughs, so the sound, after application of the necessary correction curve for the muffling, is clean, clear and accurate.
As with the outer, the Windcut design has a thick seam, which in their default design comes round one side (would cause additional muffling on that side, so not a good idea at all) - so I managed to get them to produce the inners with the seam on the top or bottom, where it would be most removed from, and equidistant from, the 'line of sight' of the D100 microphones at their wide-angle setting. That's the same as I had for the outers.
This combination has now had a really good field testing in extended recordings, with quite stiff wind gusts coming around, and, while of course not stopping all wind, it has held up remarkably well and enabled me at last to get breezy recordings as readily as I could do with the PCM-M10 and a Røde DeadKitten (original version).
The colour of the extra-thick fur that Windcut used for my furries is black, but although for my own purposes I definitely much prefer a light colour, at least the black doesn't so readily attract the attention of passers-by, which is an important plus-point as a surprising number of people lack the intelligence or sense of personal responsibility to simply pass by, and would seek to interfere with the recorder if I'm not right there guarding it. That's not just a guess but is what I've actually experienced!