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A windy weekend with the Rycotes

November 8, 2021
Rycote HC-15 and HC-22 shotgun mics in Rycote Nano Shields: furry windjammers needed too in 34 mph wind.

Last weekend was blowy and autumnal here in Norfolk, so I had a bit of fun out in the wind with the Rycote shotgun mics that I have been testing, in this case with the new Rycote Nano Shield kits: the NS2-CA for the HC-15 short shotgun and the NS4-DB for the HC-22 medium shotgun. The Nano Shields are impressively light and small, even if the deliberately bendy (but resilient) structure seems a bit unfamiliar to start with.

First up, I simply stuck the mics in the garden of this quiet village, facing the road, so you can hear the sounds of wind in the trees, passing cars, and the odd actual shotgun going off. With no low-cut switches on either mic, the 80 Hz switchable low-cut filter on the XLR connector seemed useful so here is the HC-15 with no low-cut (or high-pass) filter:

And here is a recording made at the same time, but with the HC-22 and its low-cut filter switched on:

OK, there could be a difference between the two mics or the effect of the different sizes of their Nano Shields, so here’s the test reversed. First, the HC-15 with its low-cut filter switched on:

And then the HC-22 with no low-cut filter:

So the verdict: in high winds the Nano Shield 80Hz low-cut filter is effective, especially with mics such as Rycote’s own ones with no in-built filters. Evidently the new windshields and mics were considered together. There’s no sense that the wind is overloading the mic to the degree that the low-cut filter is too far down the chain to be effective. Of course, this means that you can apply a low-cut filter at the preamp stage: how good this is will depend on your preamp/recorder, but I found no discernible difference when using my Sound Devices MixPre-3 80Hz low-cut filter. This doesn’t mean that there is no value in having a low-cut filter at the Nano Shield stage since in severe wind conditions you can double up: e.g. set the MixPre-3 low-cut filter (perhaps to say 40Hz) and apply the Rycote 80Hz low-cut filter too.

While doing various tests in the garden, out of idle curiosity I also set the two shotgun mics up as a NOS pair (capsules at 30cm spacing, angled out to 90 degrees between the mics). Despite being manifestly different mics, the identical capsule and preamps mean that it works surprisingly well. If nothing else, it’s a demonstration of how well the two mics match if cutting from one to the other. Sorry about the rather theatrical footsteps stamping past at one point!

Out in the woods on a windy day with Rattlebox for some mic tests…

Off then to the woods to test the mics in wind on something different. Perhaps it’s just me, but the woods around north Norfolk in early November seem pretty dead in terms of sound apart from wind (maybe I simply lack the patience to lurk about for hours like a real wildlife sound recordist?), so for a bit of acoustic interest I persuaded Norfolk’s raucous folk band, Rattlebox, to do some unaccompanied singing (Dick Shannon’s ‘The Auld Triangle’): this was also for my tests on double mid-side recording with two forward-facing mics, for which see my separate post. Anyway, in terms of the Rycote mics, here’s a rather unfair test of the HC-15, pointing into a semicircle of singers – fine for the lead vocalist, but, as intended with a shotgun mic, rejecting much of the other singers in the choruses that were more side-on to the mic:

Combining with an AKG CK94 for a mid-side pair changes things rather, as you’d expect. The HC-15 works rather well in this manner:

Finally, returning to the stereo experiment in the garden (above), I set up the HC-15 and HC-22 as a NOS pair (as shown in the photo above – which also shows a double mid-side rig in a Rode blimp), with the following result:

Again, I’m not recommending mixing a short and a medium shotgun as a stereo pair, but it’s not bad.

So the final word on the wind tests? Well, needless to say these were much more extensive than shown in this short post, but it is clear that the Rycote mics handle themselves fine in windy conditions. The Nano Shields – which I haven’t reviewed as such – are a good match and their performance belies their small size and light weight. Finally, and rather incidentally, those slightly tongue-in-cheek NOS stereo pair tests with the two different mics confirm both that the off-axis sound is rather good, and that the two different mics match very well.

Audio Gear

Variation on double mid-side recording

November 7, 2021
AKG Blueline mics used for these tests, top to bottom: CK93 (hypercardioid), CK94 (fig 8) and CK92 (omni): initial rig.
Second setup, bringing the three mics closer together (5mm apart): physically more stable, mics further from edge of the blimp, and fewer phasing issues.

Mid-side recording is a familiar technique to most sound recordists: a coincident stereo pair that is flexible and handy (not least as it can fit in a blimp or windjammer more easily than most pairs). I’ve written previous posts about my mid-side rigs, both for LDC mics and SDC mics. Double mid-side, where the fig 8 side mic is used by two mid mics – one facing forward and one facing backwards – is less used, but still well known, mainly by those recording surround sound. But, of course, the fig 8 side mic can also be shared with two (roughly) forward-facing mid mics: say one pointing up to the mouth of a singer-songwriter and one down to their guitar. Matrix the two mid-side pairs and you have stereo for both vocal and guitar, with reasonably little spill, and – with all three mics coincident – no phasing issues. Hugh Robjohns wrote an article for Sound On Sound about this use a few years back.

But there is another use for double mid-side with the two mid mics facing forward, and one that is rarely used or described: that’s where the two mid mics are pointing the same way but have different polar patterns. Using, say, omni and hypercardioid mid mics, you can matrix either with the side mic and get omni or hypercardioid mid side or matrix both and mix and you can get all the polar patterns in between for your mid mic: say, wide cardioid or cardioid as well as the omni and hypercardioid. This flexibility in polar pattern is quite separate from the familiar aspect of mid-side recordings, where you can vary the width of the stereo image by changing the proportion of mid to side mic: with this arrangement you get both stereo width and polar pattern flexibility in post, and – if using SDC mics – all with a very compact three-channel rig. As you can see, with a few Rycote back-to-back clips you can even fit it in a fairly standard 100mm diameter blimp.

Here’s a vocal test with a group (Norfolk’s raucous folk band, Rattlebox) arranged in a semi-circle around the mics outside on a very windy day (about 20 mph wind), singing Dick Shannon’s ‘The Auld Triangle’: the test was in part to see if the mics would be OK stacked in a standard (in this case Rode) blimp in reasonable wind (the top and bottom mics were nearer to the edge of the blimp than is ideal: at this stage I hadn’t come up with the more compact triangular array). The configuration needs the fig 8 centrally, which is good as fig 8 mics are the most sensitive to wind. The three mics had their 75Hz low-cut filters engaged to counter the wind noise. I matrixed, or decoded, each mid-side pair, so in the video you hear these on their own and then mixed 50:50. In the video, I call this mix of the two pairs a ‘virtual cardioid mid mic’) as it isn’t far off mid side with a cardioid mid mic: of course, a seamless range of possibilities from omni to hypercardioid is possible.

And here’s another test, this time with a guitarist (Luke Chapman) in his workshop (by day Luke is a woodcarver), with the same matrixing/decoding options. With no wind to contend with, the three mics have no low-cut filters engaged. Of course, the smaller sound source of a guitar means the changes in mid-mic polar pattern are fairly subtle.

How best then to process the three channels of audio in post? Well there might appear to be three options: 1) mix the two mid mics first, then decode to LR stereo as per normal mid-side; 2) decode each mid-side pair then mix the resultant LR stereo files; and 3) decode one mid-side pair then mix in the additional mid mic.

A bit of maths shows the first two are identical:

Mixing the mid mics first:
M = μM1 + λM2
L= μM1 + λM2+S
R= μM1 + λM2-S

Decoding each mid-side pair then mixing:L1=M1+S L2=M2+S
R1=M1-S R2=M2-S
L=μL1+λL2
= μ(M1+S)+ λ(M2+S)
= μM1 + λM2+S

Decoding one mid-side pair then adding the M2 mic (centrally) to the stereo pair, however, gives a different result (as, indeed, you might conclude intuitively when thinking about it):
L = μ(M1+S)+ λM2
= μM1 + λM2+μS

So avoid this third option.

[NB I’ve just done the L channels in the second and third examples, to reduce the off-putting maths…]

In my case, I’ve gone for the second option as it is difficult to determine what mix of mid mics you might want – i.e. what mid-mic virtual polar pattern – without hearing the stereo sound. I must now set up my DAW (Reaper) so that raising one stereo channel reduces the other by the same amount to make assessing the balance/mix easier.

In terms of monitoring when recording you can either just listen to the channels in mono or, with any reasonable recorder, send two of the channels (the fig 8 and, say, the hypercardioid) to be decoded in the headphone monitoring or in the LR mix (either are possible on my Sound Devices MixPre-3): in this way you get confirmation that at least one of the stereo pairs sounds as you want it. With time on your hands, you can, of course, check the other pair in LR stereo too.

UPDATE (9.11.2021). By request I’ve recorded some ambiences (just my quiet Norfolk village street from my garden) with this rig and have uploaded the iso tracks (AKG CK92 omni; AKG CK93 hypercardioid; and AKG CK94 fig 8), the two separate MS recordings (as LR stereo) and the combined MMS recording (giving something akin to cardioid MS). These recordings were made with my modified array (i.e. the mics set in a more compact triangular arrangement, each only 5mm apart from the others).

Audio Gear

Field recording with the Rycote HC-15 and HC-22 mics

October 25, 2021
Out capturing ambiences with the Rycote mics

Following on from my initial tests and review of the Rycote’s first mics – the HC-15 and HC-22 shotgun mics – this shorter post adds some tests of ambience and nature recordings with both mics individually and combined with an AKG CK94 fig 8 mic to give mid-side stereo recordings.

Kicking off at home, I recorded the sounds of what I thought was my quiet Norfolk village street at dusk: birds calling, a tractor passing etc. So I could get the different mid-side recordings at the same time, this meant putting the two Rycote mics and fig 8 together in a blimp as shown in the image below. Experience says that there will be only an imperceptible shadowing effect by the clustered configuration of the mics. The AKG CK94 has a much lower sensitivity, so I added 8dB of gain: it should perhaps have a little more (another 4dB?), but I have posted the individual wav files anyway below.

Rigging three mics for the simultaneous HC-15 and HC-22 mid-side recordings.

Here are the various village street ambiences, both the two mid-side recordings and the individual tracks. I’ve included the AKG CK94 track too, since it shows the origins of any hiss: the two Rycote mics, of course, have unusually low self-noise for shotgun (indeed any SDC) mics at 8.5 dBA (+/- 2 dB).

Looking inland at Cley beach, over the salt marshes.

Heading to the beach with just the Rycote HC-22 and the AKG CK94 in a blimp, here are some more recordings, one slightly away from the waves (with bird calls) and one close to the sea. This time I’ve included the mid-side recordings and the HC-22 tracks on their own. And this time the CK94 fig 8 mic has its gain up 12dB from the Rycote mic, to fully compensate for its lower sensitivity. Watch out for listening levels, especially for the waves – much louder than the village street ambiences above.

Recording the static bells in the massive early 12th-century belfry at Norwich Cathedral.

For something very different, I headed off to Norwich and up the tight spiral stairs into the belfry at the cathedral. The bells have been hung for static chiming since the 19th century, but the five bells (four from the late 15th century, one from 1635) still mark the hours and the quarters. And, needless to say, they are very loud within the belfry. In the recordings – again mid-side (this time with the HC-15 and the AKG CK94, and, for comparison, the hypercardioid AKG CK93 with the AKG CK94) – you can hear the wind whistling through the louvres, the clock setting the chimes in motion, and the automatic clappers chiming the bells.

Obviously using a shotgun mic as part of a mid-side pair for stereo ambiences is a slightly odd choice, and not one I would make normally, but there is a relevance to such tests as location sound recordists do use this combination when they want stereo coverage in addition to the focus of their interest with the mono shotgun. A more typical use of the shotgun mic for nature and sound effects recording, of course, is for focusing tightly on point sources for mono recordings, and with the low noise and good off-axis sound, there is little doubt that the HC-15 and, for a tighter focus, the HC-22 are excellent choices.

Audio Gear

Rycote’s first microphones – review and tests of the HC-15 and HC-22 shotgun mics

October 13, 2021

New microphone manufacturers appear from time-to-time, but when I heard that Rycote – with over 50 years of well-respected design and manufacturing of microphone windshields and suspensions – were producing their first microphones, this stood out as something rather different: both their reputation and experience with other mics suggested that this could be an intriguing addition to the market. Given Rycote’s long involvement with broadcast and film sound, it isn’t that surprising that the two mics are both shotguns: one 15cm long and the other 22cm, giving rise to the HC-15 and HC-22 names. The specs fueled my initial interest as did the fact that they are made entirely in the UK at Rycote’s factory in Stroud. The price is interesting too, with the HC-15 costing £560 and the HC-22 £575 (ex VAT). This places the mics in slightly underpopulated territory, well above the list prices for the Rode NTG5 and NTG3, but well below the list price of the Sanken CS1-E or, say, the Audio Technica BP4073. Many staples of location sound recordists – such as the various shotgun mics made by Sennheiser, Schoeps and DPA – are more costly still. So, intrigued by all this and knowing Rycote to be a friendly and approachable company (see, for example, their help with my oversized LDC mic windshield), I asked whether they would let me review and test the mics: a few email exchanges later, and the mics arrived last week – no conditions/obligations applied nor, indeed, any timescale for their return! They included some foamies and a Classic Softie kit, with a Nano Shield (out of stock) on its way soon.

The approach

I don’t know about you, but I’m not overly excited by mic reviews – usually vlogs – that involve unboxing and reiteration of the published specs, in this case readily available online on the Rycote website, along with some tests of the mics in an unlikely location (e.g. with shotgun mics locked off above a vlogger’s head in their indoor studio). Of course, there is a value in comparative tests of mics, despite the danger (for shotgun mics) of these ending up being grouped in static arrays, but the number of professional shotguns available means that this is outside the scope of what I can do: for the nuances of Mic A vs Mic B there is no substitute for testing and working with both mics yourself and no review or on-line test is going to replace that. Rather, the focus of this review is a series of more real-world tests with the two Rycote mics, some out and about on location, with the aim to see if the Rycote mics are contenders for serious use. Sometimes I use another mic for the purpose of comparison, or to illustrate a point, and mostly I use the HC-15 and HC-22 together – which at least helps clarify the differences between the two. Sometimes I use the HC-15 and HC-22 in combination with a fig 8, to see how they stand up is the mid mic in a mid-side stereo pair: common use for a shotgun mic. But you won’t find any tests of the mics mounted on a camera: I’ve yet to find a need for this, and my gut feeling for such use is the compromised positioning means a more modest shotgun (and perhaps one without P48) will do the job.

Rabbit rabbit

With dialogue or speech recording being key uses for a shotgun mic, I was keen to put the Rycote mics through their paces on voices. There are many different aspects to this, but the ones I was keen to test were overall sound (Rycote describe their mics as ‘precise’ and as having ‘a crisp sound with some additional warmth’) and off-axis response (how coloured is the sound off-axis?).

For this test, I went to a small local theatre (the Sheringham Little Theatre) to use its stage: not a huge sound-treated stage, but a step up from a village hall, and did some tests with the writer (Chris Sainton-Clark) reading excerpts from his one-act play ‘My Other Half’ statically (with the mic on and off axis), and moving about (to see how susceptible the mics are to comb filtering in such a less than ideal interior space). To make it easier to follow the various positions, I have put this test into a video. Oh, and, yes, I know the 180 degrees off-axis test is fairly mad!

Putting the shotgun mics into tougher conditions, I then dragged Chris onto the pavement outside the theatre to ad lib as if for an interview (quite fairly, he chose to promote the theatre where he works!) against the backdrop of the entrance (which houses a bustling café), with noisy traffic and people behind the mic on a busy junction at the centre of the town:

Play it again, Luke

Rarely is a shotgun mic much use in a music studio or, even, for remote location recording of music (e.g. in a church or concert hall), but sometimes the polar pattern of a shotgun mic is necessary. Recording music is also a good test of any mic, so to put the Rycote’s mics to this use I chose to record a guitarist in an indoor non-studio space (a woodcarver’s workshop).

Here are the two mics used to record ‘Moth to a Flame’, written and performed by Luke Chapman. I’ve also included a third version, with the HC-22 paired with an AKG CK94 (i.e. SDC fig 8 mic) to show how the Rycote mics perform as the mid mic and a mid-side stereo pair. The sound is just as it came off the mics, recorded into a Sound Devices MixPre-3.

And here is a short video with clips of Luke Chapman playing the guitar and singing, with the sound (as shown on the screen) switching from HC-15 to HC-22 to HC-22+AKG CK94 mid-side. Again, there is no editing or effects. The limitations of using a single shotgun (even if in one version, combined with a fig 8 side mic) for recording both guitar and vocals simultaneously are evident, and not something I would normally do (in fact, I’m currently recording an album with Luke using three fig 8 LDC mics), but it worked rather better than I thought. And, of course, sometimes a shotgun mic (or shotgun-based mid-side pair) might be an effective solution: e.g. a run-and-gun recording of a busker in a noisy street.

Let’s get physical

While the sound of the mics is the focus of this review, another aspect not clear from the specs is the physical nature of the mic. That is the build quality (insofar that this is clear without dismantling it and using it for years in all conditions), the handling noise (shotguns are forever on the move, at the end of boom poles or on pistol grips), and susceptibility to wind noise.

Build quality seems excellent. With no high-pass filter or pad switches, there are no moving parts to assess, so it’s a simple design. The mix of materials is unusual feeling, but not in a bad way. The brass barrel of the pre-amp (as opposed to the aluminium of the capsule section and interference tube) has a bit of heft (though these are light mics at 90g and 100g): this takes the centre of gravity of the HC-15 a little back from the red ring, and with the HC-22 it is around the paired slots behind the diaphragm. Access to the innards is evidently by release of the brass circlip in the XLR socket, which seems preferable to a screw (the circlip also grounds the mic body to pin 1): I didn’t open up the mics though…The wooden cases are classy, well made and close in a satisfying way (simple pleasures!): not sure many would use them in the field though. More attractive is the lack of gubbins with the mics: no additional equipment means you aren’t paying for things you so often don’t need.

Close-up of the XLR socket with circlip.
How they come: just the mics, the rather lovely cases and the simple cardboard packaging.

Testing for handling noise transmitted via a boompole required some deliberately bad booming aiming for maximum transmission of vibration to the mics (on an Invision 7 suspension). Unsurprisingly the two Rycote mics are pretty similar, with all the unwanted noise below 50Hz (and therefore addressable by a low-cut filter, if not, of course, by better technique). By way of comparison, here are test files for the HC-15, the Oktava MK012 with the hypercardioid capsule, and the AKG CK93 (hypercardioid), which reveal no major differences:

Wind noise on a mic varies with polar pattern, of course, and, while wind protection from a slip-on foam cover, through softies to a full blimp can address the issue, it is good to examine the baseline susceptibility. For this – not least given relevance to actual use – I have just gone for some simple fast boompole swings, with the mics mounted together. The HC-15 and HC-22 are not that different, with the HC-22 (reflecting better rejection of the sides) performing better than the smaller shotgun:

The susceptibility to wind appears pretty normal for a shotgun mic and even lower-cost versions perform well. Here for example, is the HC-22 compared to the Rode NTG1 (levels adjusted to reflect sensitivity), with the latter a bit quieter:

But comparing the Rycote shotguns to other types of boompole mics – in this case hypercardioids – shows a significant difference: even the more wind-susceptible HC-15 easily outperforms the AKG CK93 and, by a huge margin, the Oktava MK012:

Silence is golden

Of the specs the one that immediately stood out to me was the 8.5 dBA (+/- 2 dB) self-noise. This is about as low as it gets for a shotgun mic (think Sennheiser MKH 60 at 8dBA) and is much better than most of the professionals’ favourites. Diaphragm size is a significant factor in mic self-noise, and, while the size isn’t published, Rycote have told me that a 17mm-diameter diaphragm has been used (not bad in a 19mm-diameter mic body). Of course, not all mic manufacturers measure self-noise in the same manner nor is all self-noise the same, so my first test with the mics was to record nothing. Well, as near nothing as possible outside an anechoic chamber or a nuclear bunker: in the hallway of my house in a rural village, I closed all doors, turned off the mains electricity at the consumer unit, and left the two mics recording into a Sound Devices MixPre-3 (EIN -130dBV/-128dBu) along with a Rode NT2-A (at 7dBA in the same ball park). Self-noise was indistinguishable between all three mics. There’s not a lot of value to uploading WAV files showing the slight hiss with gain cranked up wildly, simply to confirm the published spec, but listening to the boompole handling-noise sound samples above makes clear the difference between the Rycote mics and mics with higher self-noise (the AKG CK93 self-noise is 17dBA and the Oktava MK012 self-noise is 18dBA).

Final thoughts

These tests are neither exhaustive nor especially technical: no anechoic chambers or such like were involved. Nor do they rigorously compare the HC-22 and HC-15 to a whole range of other shotgun mics. But the process of carrying out the tests has shown me that Rycote’s first foray into mic design has huge merit: these mics thoroughly deserve to be considered as alternatives to familiar mics above and, indeed, below their price point. The low self-noise and healthy output makes the mics obvious contenders for nature and effects recording; the same attributes, low weight and good off-axis sound make them contenders for film and TV sound; and the same specs/construction for the two models with different interference tube lengths mean that they are ideal if you want to swap seamlessly from one type of shotgun to the other. Having got my hands on them, I certainly don’t want to send them back to Rycote!

Audio Gear

AKG Blueline mics

August 28, 2021
AKG CK91, CK92 and CK93 rigged for testing

Having had the hypercardioid (CK93) capsule of the the AKG Blueline modular mics for some years (with the SE 300B body/pre-amplifier), I picked up the fig 8 capsule (CK94) and another SE 300B a few months ago (see my post on it here), and have just now added the CK91 cardioid and CK92 omni capsules to the family: a good used bargain, all the way from Shetland, in excellent condition. Although the CK91 cardioid was apparently a staple of radio studios etc. for many years, in the filmmaking world a myth has built up that the hypercardioid was the cream of the crop and by far the best capsule. I suspect this came about since the AKG CK93 is an excellent hypercardioid, and much better than the few alternatives that were available for a modest price (e.g. the Oktava MK012) rather than based on any actual hands-on comparison between the different Blueline capsules.

Certainly, I have begun doing tests and am impressed straight away by how remarkably similar the capsules sound – initially just testing on acoustic guitar and vocals. There really is no stand out or weaker capsule amongst these four (I can’t speak for the CK98 shotgun capsule, which I don’t have and haven’t heard). And equally impressive is how rounded or smooth they all are. For instance, the CK91 cardioid has none of the brittleness of my Rode NT55 cardioid capsules. A surprising extra is that the AKG CK91, CK92 and CK93 capsules also have less evident self-noise than the Rode NT55 mics, despite the specifications suggesting the reverse (17dB vs 15dB). These really have to be some of the most underrated mics out there: great value new (if you can find stock still, as they appear to be being discontinued) and even better used.

I bought the latest two AKG capsules to give me more options for a mid-side pair with the CK94 fig 8 capsule. OK I could use other SDC mics I have (such as the NT55s), but it is nicer to have a more consistent sound across the pair in the mid-side array: that the AKG capsules also sound better is a bonus. When I get the opportunity I will post some samples with the various capsules.

AKG CK91 (cardioid), CK92 (omni), CK93 (hypercardioid) and CK94 (figure of eight) capsules on SE 300 B pre-amplifier bodies. Note some slight visual variations over time with the pre-amplifiers (oldest is on the CK94; next oldest on the CK91 and CK92; and the newest on the CK93): I can’t hear any difference in their performances, but have yet to compare the circuits.