I’ve long been a fan of simple set ups for music recording, often using a mid-side pair only. That’s partly due to the fact that I like the idea of a stereo capture (rather than close-miced instruments and vocals panned across the left-right field), but also reflects the nature of what I do: location recording, with no studio and the natural tendency there – since the 1970s – to use multi-mic and multi-track recording, overdubbing and tinkering for as long as you wish. This is not to deny that there’s a hugely creative side to the typical studio recording approach, and it allows you to record instruments in ways just not possible without it. Of course, a simpler approach has remained the case with much recording of acoustic and classical music, although, even there, the number of spot mics can be vast these days. But recording of bands – with drum kits, electric guitars etc. – has been largely the province of the multi-mic and multi-track approach in recent decades, with only the occasional exception.
One such exception I have enjoyed has been John Cuniberti’s OneMic series of recordings. John is a hugely experienced engineer, with years of the studio multi-tracked approach under his belt, so it has been fascinating to see and hear his journey into a simpler approach: in his case using a stereo pair of ribbon mics, arranged as a Blumlein pair, in the form of the single stereo AEA R88. John has an excellent YouTube channel with examples of his recordings and videos, as well as behind-the-scenes videos, which are invaluable for others attempting something similar.
With a pair of the latest pre-production Rycote BD-10 fig 8 mics in hand, I was keen to try something in this vein: that is, to capture a whole band at the same time just with a Blumlein pair. Besides, what’s the point of a fig 8 mic without a good Blumlein work out? With a fraction of the skills and resources of a Cuniberti, expectations were much lower, but that’s not a reason not to have a go!
For anyone not familiar with the approach – which, like so much in stereo, goes back to the work of the brilliant engineer Alan Blumlein in the 1930s – a Blumlein pair comprises a pair of fig 8 mics usually arranged directly one above the other, so that the two mic capsules are angled at 90 degrees to each other: in that sense, like an XY pair. This gives you a stereo field in front of the mics and, with the rear lobes of the mics, to the rear: the stereo field to the rear, of course, is flipped. There’s plenty of signal at the sides of the pair, but it’s not the place for a direct sound source: at right-angles to the pair a source would be, say, on the left from the perspective of the front lobes, and on the right from the perspective of the rear lobes. Quite evidently, a recipe for a phasey mess. So, a Blumlein pair isn’t the answer to micing a group ranged in a circle around the mics, but does let you spread them in an arc of 70 degrees in front of the mic and a similar arc to the rear. Setting relative levels of different instruments and vocals is, needless to say, a question of adjusting loudness of the sources and/or distance from the Blumlein pair.
So much for the theory: the task is to translate that into action. With Lucy Grubb and her band willingly volunteering for the exercise, choice of venue was largely dictated by the need for good monitoring: with ‘mixing’ created in the setup, it was essential that the band and I could listen back and adjust the set up as necessary. The bassist, Kev Burton, happily let us use his studio – The Forge – where the band has previously recorded their multi-track releases: the wonderful Midas desk (originally made for Frank Zappa) was reduced to monitoring duties (from a passive split and feeding Logic), while the primary feed from the Blumlein pair was to my Sound Devices MixPre-3 recorder. Kev’s experience with his studio and the expert ears of the band were crucial to getting the balance right.
It was a tight squeeze in the small studio, with the hardest thing controlling the level of the drums, even with brushes and a special kick-drum beater: there was only so far we could move the drums away from the mics, so the drummer, Paul Weston, detuned his snare to great effect, and we put a gobo in front of the kit. The electric bass amp was placed on a chair in front of that (to get the bass central and nicely balanced with the kick drum), with Richard Poynton, on electric guitar and singing backing vocals, nearer the mic, and a little to one side. Closer to the mic, but centrally on the other side, was lead singer (and song-writer) Lucy Grubb, playing acoustic guitar (with a little amplification behind her). Left and right of her amp, were amps for Richard’s guitar and for the keyboard of Piers Hunt: all three were on chairs/beer crates to get them off the floor. Placement of the keyboard and the bass players themselves didn’t matter: it was all about the position (and volume) of their amps.
There was precious little room for any lights or cameras, but, nonetheless, a rough and ready film of the recording seemed worthwhile, so here – with a video of one of the three songs we recorded – is what I managed. The sound has seen no processing other than addition of a little reverb: there is no compression, EQ etc.
So the verdict? Well that’s one for others perhaps. But from my perspective and, more importantly, that of the band, what we got was a very faithful sound of the band in the room. Everyone was engaged in the idea of balancing or ‘mixing’ at source and I suspect we’ll be back having another go before long. Oh, and the BD-10s faired rather well as a Blumlein pair, I thought!
For anyone who has been following the foray of long-established and respected maker of mic windshields and suspensions, Rycote, into manufacture of mics themselves, the announcement of the BD-10 fig 8 at NAB 2023 is an exciting development. With two shotgun mics produced in 2021 and then, in 2022, omni, cardioid and supercardioid mics, a fig 8 mic was undoubtedly the most hoped-for mic to give a reasonably complete range. You might wish for a wide cardioid too (or variations on the existing polar patterns – a free-field omni mic, for example), but there is no doubt that a fig 8 mic is vital to Rycote’s range of mics for several reasons: first, Rycote’s established customer base is founded on field recording and, especially, those recording sound for film/television, where mid-side recording – and a fig 8 mic – is a key tool; and, second, the company needs a full range if it is to tempt users away from more established manufacturers. That there are few such complete ranges, with a fig 8 mic in the sub-£1000*mic category adds to the significance of the BD-10: with the recent demise of AKG’s competent Blueline mics (launched 30 years ago), I can’t think of another manufacturer producing mid-priced SDC mics with a fig 8 in the line-up other than boutique Taiwanese mic-maker B9Audio (with almost no reviews and mics only available direct from a private address in Taipei, B9Audio is not viable for most) and, possibly, respected German manufacturer MBHO (I say possibly, since the MBHO website has long since failed to list the KA 800 fig 8 capsule, pricing is uncertain, and, again, distribution is not similar to most mainstream mic manufacturers: for example, I can’t find any MBHO mics in stock in the UK). And one-off SDC fig 8 mics (i.e. not forming part of a range of polar patterns) in this category are rare too. Perhaps more surprisingly, not all mic manufacturers producing SDCs in higher price brackets have succeeded in producing a fig 8: most obviously, Sennheiser has never managed to bring a much-anticipated MKH8000 series fig 8 to market (although the excellent, albeit large for an SDC mic, MKH30 has remained in production since launched in 1987), and DPA similarly has no SDC fig 8 offering.
*NB: though Rycote has yet to announce pricing, it will almost certainly be in this category, but perhaps a little pricier than its £670 SDC siblings.
The Rycote BD-10, on paper, then looks like it will be a welcome addition to the market, when it becomes available (probably not until the autumn). Its self-noise is comparable to that of the Schoeps MK8. It is a little (22mm) longer and heavier (15g) than Rycote’s omni, cardioid and supercardioid mics, but not radically so. This reflects the capsule design, which, I understand, is a pairing of 11mm diameter diaphragms one above the other with a waveguide to blend them: the polar pattern graph shows a very symmetrical result from this arrangement, but, of course, the proof of the pudding is in the eating. So, what is the mic like in reality? On to some field tests and trials.
NB The mic tested was a prototype, and the final specs of the BD-10 in production may differ slightly.
As with all mics, I was interested in the impact of radio frequency interference (RFI) on the BD-10. Living in rural Norfolk, much of my life is outside or on the edge of mobile phone reception, where some models of phones transmitting at full power can cause notable interference on mics at up to, say 1m/3ft: not a problem with mics on a stand, but I’ve had this become a real issue with handheld shotgun mics and a phone in my jacket pocket (on those rare occasions when I forget to turn my phone off). And this could be a problem with ENG work too (not least from the phone of an interviewee). So I was glad to find that in testing, as before, with several different phones on the absolute fringe of reception (i.e. working at highest power) the mic showed no sign of RFI even at close distances (100mm): the other Rycote mics are similarly resistant to RFI.
Self-noise and sensitivity
With an 18dBA self-noise figure the BD-10 has significantly more self-noise than its stablemates, which are the HC-15 and HC-22 shotguns at 8.5dBA; the omni OM-08 at 11dBA; the supercardioid SC-08 at 12dBA; and the cardioid CA-08 at 13dBA. The previously released Rycote mics, however, have unusually low self-noise, and higher self-noise for SDC fig 8 mics is normal. For example, at 17dBA the Schoeps MK8 has a very similar self-noise figure to the Rycote fig 8, and, again, 7dBA more than its MK 2 omni capsule counterpart (10dBA). In short, the BD-10 is in good company and 18dBA self-noise for a fig 8 is respectable.
A check on the reality of the 18dBA figure – by recording the sound of nothing (the mic buried deep in duvets in the airing cupboard, with all doors and windows closed and the mains electricity turned off, recording into a Sound Devices MixPre-3 [EIN -130dBV/-128dBu]) and with reference to other mics – confirmed that the self-noise is indeed around that stated.
Testing this in the real world, I rigged the BD-10 as an MS pair with a cardioid CA-08, and a second SDC fig 8 in the form of the AKG CK94: the latter, although just discontinued, is a rare example of another sub-£1000 SDC fig 8 mic with a full frequency range.
First off, recording the ambient sound of my nominally quiet Norfolk village street (yet again!) even in the quieter parts there is no evident difference between the two Rycote mics, but hiss from the AKG CK94 is clearly discernible, which reflects its 22dBA self-noise spec.
Turning to a quieter environment, it was useful to test the BD-10 indoors, in this case with some sound effects/indoor ambience: the mic was set up as a mid-side pair with the cardioid CA-08 in the middle of the kitchen, with various household noises – and some silence – recorded. The AKG CK94 was also paired with the CA-08 for comparison. Here are the two MS tracks and then the three iso tracks for the cardioid mic and the two fig 8 mics:
During the sounds such as cutlery being placed in a drawer the two fig 8 mics are both very usable, but in the quiet passages, such as near the end, the hiss of the AKG CK94 is, again, fairly evident.
The specs state the BD-10’s sensitivity as 14.2mV/Pa (-36.95 dBV). This means that the BD-10 is the least sensitive of the Rycote mics (the next being the cardioid at 24.3 mV/Pa or -32.3 dBV), but its output is still healthy. For example, it is more sensitive than the Schoeps MK8 (12 mV/Pa or -38.5 dBV) and the AKG CK94 (10mV/Pa or -40 dBV). A consequence of this is that the BD-10 has a couple more dB max SPL than its stablemates, but the more practical reason for being aware of its sensitivity is for level matching against different mics when using the BD-10 in an MS pair (matching sensitivity in the recorder in such use giving an easier starting point for monitoring and in post).
Frequency response and ‘sonic signature’
Fig 8 mics generally have a poorer bass response, although some, such as the Sennheiser MKH30 are exceptions: in this case pretty much flat down to 40Hz. The main competitor pricewise to the BD-10, the Ambient Emesser ATE 308, has a marked bass roll-off from 100Hz (if not higher), which is fine if matching for MS to a shotgun mic that has a similar roll-off, but is not ideal for other use. More surprisingly the much-loved Schoeps MK8 has a steady fall off starting from above 200Hz, and, according to its frequency response graph, is down 8dB by 50Hz: at the high end there is a sudden fall-off from 16kHz, so that the response is down by 20dB at 20kHz. The more modestly priced AKG CK94 has a less curtailed frequency response than most of these examples (bar the MKH30) being down about 3.5dB at 50Hz and a similar amount at 15kHz (with no published data beyond). On paper, the Rycote BD-10 looks hopeful: the frequency response graph shows a very gradual roll-off from 200Hz so that it is only -1dB at 100Hz, -2.5dB at 50Hz, and -4dB at 20Hz. If the graphs are correct, then this suggests, a little surprisingly, that the BD-10 has a better bass response than the cardioid CA-08 and supercardioid CS-08. At the upper end, after a little rise around 12kHz, the BD-10 is down about 5dB at 20kHz.
So much for the theory: now to reality! First, a different take on the ambient recording, in this case with the two fig 8 mics (i.e. Rycote BD-10 and AKG CK94) oriented so that in each case one of their lobes faced the rear of a parked car and, in a separate blimp, the SC-08 cardioid likewise facing the car, which was then started. The resulting mono tracks show all three mics capable of rendering the lowest fundamental (at the lowest engine idling speed around 24Hz), with the BD-10 showing more low frequency response than the AKG CK94, but slightly less than the cardioid CA-08: this isn’t a surprise in terms of an expectation of a fig 8 mic versus a cardioid, although it is not what would be anticipated from the frequency response graphs. Graphs aside, though, it is clear that the BD-10 has a good bass response for a fig 8 mic, which suggests good capability for, say, music recording or effects and field recording with a bass component.
At the upper end, it was interesting to see if the BD-10 had any of the extended high-frequency response found in testing of the other Rycote SDC mics. As with the comparison of the Rycote OM-08 and Sennheiser MKH8020 omni mics for extended high frequency response, I recorded a street ambience at 96kHz instead of 48kHz, in this case including the OM-08 and the AKG CK94 alongside the BD-10 for comparison, with levels adjusted to reflect the different sensitivities. As with the omni mics comparison, again the spectrograms are revealing: they show the extended high-frequency response of the omni OM-08, as now expected, with, for example, the gate latch-shutting sound (that tall spike near the right-hand side of the spectrograms) reaching about 48kHz, and the wider spike of the passing tractor (towards the left-hand side of the spectrograms) reaching around 35kHz, and, as would be expected, with much more low-frequency content. The BD-10 shows both clearly, showing that the different capsule design for the fig 8 mic still has a very respectable extended high-frequency response to near 48kHz: moreover, the BD-10 is like the OM-08 in that it is consistently low in terms of self-noise up to the top of the graph (around -136dB at 48kHz) in stark contrast to the previous comparison of the OM-08 and Sennheiser MKH 8020 (where the Sennheiser had considerable self-noise in the extended high frequency range, although not, of course, in the human audible range). The AKG CK94 has a rather lower extended high frequency response, although rather better than anticipated from previous tests on the other Blueline capsules, and has a little more self-noise at such frequencies (as, of course, it does in the audible range). As discussed previously, extended high-frequency response might seem entirely academic outside those recording at high sample rates and pitching down in post (e.g. for bat recordings, or for sound effects), but there are those that argue frequency response over 20kHz is important for high-resolution recording (such as David Blackmer of Earthworks mics in this article). If so minded, there is no doubt that the Rycote fig 8 is a respectable performer over 20kHz, comparable to the other Rycote SDC mics, and with much lower self-noise a useful benefit of the not quite as far extended high-frequency range as found in the Sennheiser MKH 8000 series mics.
Putting this good low and high-frequency response to practical use, I tested the BD-10 on a guitar to cover a wider frequency range. At the same time, given that the previously produced Rycote mics are described by the manufacturer as having ‘a tonal and sonic signature that makes them cut together seamlessly’ and that this relates to frequency response, I also included the omni, cardioid and supercardioid mics in this test, placing mics at the relevant increasing distances to allow for their different polar patterns to reduce the impact of different reflections: the omni mic was placed at 400mm, the cardioid and fig 8 at 680mm (distance factor of 1.7) and the supercardioid at 760mm (distance factor of 1.9). To make comparison most straightforward the wav file has a single strum from each mic in turn (omni, cardioid, fig 8 and supercardioid in turn), followed by a short space and repeated another three times. This was carried out in a normally furnished living room, with a low ceiling.
It is hard to draw definitive conclusions from this simple test. Matching levels was extraordinarily difficult given the different frequency content and different reflections resulting from the different polar patterns, distances and frequency responses: in the end I settled for calculating the impact of the differences of distance and sensitivity. There is, as would be expected, a slight change in the sound as the polar patterns and distances change, and, despite being at the same distance, there is a difference between the fig 8 and the cardioid mic: to a significant degree this is the impact of the greater bass response of the cardioid. Interestingly, the fig 8 and the supercardioid have a very similar sound, doubtless reflecting the reduced bass response of the latter (and, of course, its greater distance: less proximity effect). In short, though, the ‘sonic signature’ for the mics is close enough that I wouldn’t hesitate in using the BD-10 with any of the other mics in a mid-side or double mid-side array.
The BD-10 will have a wide range of applications, but this is likely to include use on a boompole in a MS or DMS rig, so handling noise performance is relevant: all other things being equal, fig 8 mics are the most susceptible to handling noise. Testing for handling noise transmitted via a boompole involved some deliberately clumsy booming, aiming for transmission of vibration to the mics. Three mics were included in the test (i.e. rigged together on a Rycote Invision suspension with back-to-back clips) to allow comparison: the Rycote BD-10, the Rycote SC-08 (supercardioid) and the AKG CK94 (fig 8). Gain levels were adjusted for relative sensitivities.
When holding the boompole still only the BD-10 showed any significant handling noise, which peaked at -38dB, with LUFs at -68.7dB. Evidently this was trembling/vibration from the boom operator’s muscles holding a steady stance, and was all low-frequency energy below c.35Hz: a high-pass filter – a pretty essential adjunct to booming – removes such energy. In the second recording of boompole handling an 80Hz high-pass filter was applied and the low-frequency content in the BD-10 recording is absent: in this case, however, some medium clumsy handling transmits more to the mic than to either the SC-08 or the CK94, which perform very similarly (about 10dB lower noise in terms of LUFs compared to the BD-10). In the third boompole handling test, with extreme rough handling – rather implausibly so! – the difference between the BD-10 and the other two mics remains similar at around 10dB. While previous tests against the AKG CK93 and Oktava MK012 hypercardioids revealed the SC-08’s ability to cope with handling noise rather better, it is clear that the BD-10 doesn’t perform as well as its stablemate or, indeed, the AKG CK94 fig 8, but, other than that sub-c.35Hz transmission – which can be easily cut off by use of a high-pass filter at 40Hz or above – it should offer no problem to the user given a suitable suspension and experienced boom operation (not forgetting that capture of stereo ambiences on a boompole is usually for incidental B-roll, camera perspective stereo etc., not whilst executing complex and rapid boompole movements for dialogue recording!).
Fig 8 mics are especially susceptible to wind noise, so it is interesting to explore this aspect of the BD-10’s performance. To get a base line, a triple rig of BD-10, SC-08 and AKG CK94 was used again, this time, however, with the mics in separate Invision suspensions, spaced along a stereo bar so that no mic was shielded from the wind by the others, and mounted on a boom pole. Fast boom swings were made to generate wind noise, not to represent typical usage of a fig 8. Gain was set as for the handling noise tests (see above). Swinging the bare mics produced overwhelming rumble, as would be expected: the SC-08 and BD-10 performed very similarly, while the AKG CK94 performed rather better (about 13dB better in terms of peak and LUFs). Of course, such use is unrealistic: even with a modest amount of boom movement indoors (or the gentlest air movement around a static mic indoors) at the very least a foam windshield would be used, so the test was repeated with the manufacturer’s original foams on all three mics. Again, the two Rycote mics produced similar levels of wind noise, with the AKG CK94 maintaining an advantage of around 13-15dB. Applying an 80Hz high-pass filter on the recorder in the third test evened things up rather, with wind noise much reduced and with the AKG CK94 having around a (reduced) 5dB advantage over the two Rycote mics. As was noted in the previous SC-08 wind tests against the AKG CK93 and Oktava MK012, it performed between these two mics in terms of noise and, in extensive use since, has not proved problematic. That the BD-10 performs similarly, despite its fig 8 pattern, is reassuring: of course, better wind (and handling) performance at the level of the CK94 would be welcome, but there is no reason to think that the BD-10 isn’t suited to use in wind given, as with any mic, suitable wind protection for the use and conditions.
Following up on this and placing the mic in high wind for an ambient recording confirmed this. I took a mid-side rig with the SC-08 and BD-10 mics in a medium Cyclone windshield up to the north-facing Norfolk coast on a windy day (about 20 mph or more), recording in one location on the inland side of the shingle spit, facing westwards into the wind (including some walking nearby on the shingle), and in a second location on the beach (the wind coming from slightly rear of the left-hand side of the Cyclone). Finally, back in the garden with the same rig and with the wind still blowing (but inevitably not as hard as at the coast), I then did a further recording. For the recordings, I include the individual SC-08 and BD-10 isos, along with the decoded MS and then the latter with an 80Hz high-pass/low-cut filter applied.
It is always hard to translate and communicate conditions let alone those in high wind. In none of these cases would I have attempted a nature/ambience recording as set-up for these tests: I would have sought some shelter from the direct blast of the wind (e.g. in the lee of the pillbox on the beach, or in the lee of the garden wall), not least to reduce vibration of the mic stand. But what the tests do confirm is that the BD-10 is in the same ballpark in terms of wind noise as, say, its supercardioid counterpart. In short, I’d have no hesitation using the Rycote fig 8 for outdoor field recording.
A bit of music
I recently wrote a blog post about a simple video of a singer-songwriter (Lucy Grubb), for a competition entry, and, though I mentioned use of a variation of double mid-side recording, I skipped over just what fig 8 mic I was using. As it is no longer under wraps, it is good to be able to clarify that I used the new BD-10 alongside its supercardioid (SC-08) and cardioid (CA-08) stablemates. Using the three mics, the fig 8 was set conventionally pointed at Lucy, just above the top of her guitar, so that its lobes faced left and right; immediately below this the supercardioid pointed upwards to capture the vocals, and immediately above the fig 8 the cardioid pointed downwards to the guitar – aimed around the 12th fret.
When Rycote followed up on its initial two shotgun mics of 2021 with its omni, cardioid and supercardioid mics the following year, this gave real hope that a fig 8 might follow. Evidently, the capsule design is very different to that used in the other mics, so all the more credit should go to Rycote for persisting. As I said at the outset, a fig 8 is critical to the use of so many recordists that use Rycote’s windshields and shockmounts; and it is important if Rycote wants to be seen as a real contender as a mic manufacturer. That Rycote has come up with a fig 8, and fairly quickly, is good news: that it performs so competently means that it is a great counterpart to the rest of the range. Over a couple of months (intermittently) testing the mic, I have been impressed: I will, however, continue to work with it, not least putting it through its paces on more musical sources, and more field recording. Hopefully, it won’t be long before Rycote clarify availability and pricing.