MKH 8030 – Page 2 – Dr Badphil

A tale of two MKH 8030 mics, a native B-format array and a pipe band. Part 2: recording.

August 4, 2024

Members of the City of Norwich Pipe Band arranged in two arcs, in the rather wonderful setting of Wymondham Abbey.

Introduction

In part 1 of the blog posts on recording test sessions with the City of Norwich Pipe Band (a prelude to a CD recording, with the tests focused on establishing whether recording indoors or outdoors is preferable), I covered the rationale and detail behind the microphone choices. To recap, with the band formed in both a circle and a near circle, I decided to go with a native B-format array of two fig 8s (Sennheiser MKH 8030) and an omni (Sennheiser MKH 8020), which, in terms of the required stereo end product, gave me options of mid-side with two fig 8s (i.e. decoding to a Blumlein pair), omni mid-side, and double mid-side (the latter with any polar pattern for the mid mics). And just to cover all bases, I also elected to add a spaced pair of omni mics (Rycote OM-08s). This second blog post is concerned with the recording and the results.

Location

Recording a pipe band indoors requires a large space. In the absence of a massive purpose-built recording studio (ruled out due to cost and because this was always intended as a location recording of a non-competition pipe band), I was glad to be able to arrange for use of Wymondham Abbey (many thanks especially are due to Brian Randall, churchwarden, for his help and support). The early 12th-century nave that survived the demolition of the rest of the abbey at the Dissolution (to function thereafter as the parish church for the town) is substantial, being twice the size of Abbey Road Studio One: if a small pipe band (the recording involved some members only – we had five pipes, one tenor drum, one side (or snare) drum and a bass drum) was to overwhelm the abbey church, then indoor recording would evidently be a non-starter outside a studio or concert hall.

Arranging the band

The regular formation used by pipe bands is a circle, and I could see no reason to, say, go for a more linear concert-style arrangement for recording. On the one side, recording a band in a circle is a challenge, but, as we have seen in the previous post on mic array selection, one that is solvable. But aside from the easy benefit of intervisibility for band members, this arrangement offers an additional benefit for loud acoustic instruments such as bagpipes and drums: direct sound will predominate over reflected sound from all directions. That is certainly the case if an unbroken circle is adopted, but balancing this with the array options (which included mid-side with two fig 8s) meant that these tests comprised both a full circle and a very broken circle – i.e. two opposing arcs each just under 90 degrees. With a modest contingent of the band for the test session, for the full-circle version we had the pipers occupying a little more than half the circle, which had a radius of around 2 metres. For the two opposing arcs, the pipers were all on one side facing the three drummers on the other side, with a radius of 3 metres for both arcs. We will replicate the arrangements for the outdoor test session in due course, but, evidently, any CD recording with a larger number of band members is likely to require some tweaking of the radius to accommodate everyone. That said, the band members were far from squashed together on this initial session.

Recording

Prior to the recording test session, I dropped into one the regular practices to meet the band. They hold these in the former Regal Cinema (now part of the Wymondham & District Ex-Services Social Club), so, while not a remote glen, it is far from a small room with a low ceiling. The sound of the band, however, came bouncing back from all directions and, given the reputation of bagpipes, I was a little concerned about levels before the test session. With only one pad on one of the mics (courtesy of the single MZF 8000ii filter I have – more on that soon) I was crossing fingers that I would be OK in terms of volume: with healthy max SPLs of 139dB for the MKH 8030s and 138dB for the MKH 8020, I was happy with the Sennheisers, but the Rycote OM-08 with its max of 127dB was an order lower. And then, what about levels into the recorder? Well at least with the Sound Devices 788T I had the option of using line inputs, which can still supply 48v phantom power, if things got overly hot. Needless to say, such slightly nagging concerns were entirely unfounded: with the more distant 3 metres of the two arcs I was able to set all the mic input trim/gains at 20dB, and with the shorter 2 metre radius of the full circle, I was fine with 15dB. Perhaps more reassuring too, the reflected sound in the aisled abbey church seemed much less overwhelming than the practice rooms: or was I just acclimatising!

Set up in the south aisle with the Sound Devices 788T. No overloading of mics or recorder, and I didn’t even resort to the earplugs I brought along!

The results

With the native B-format array, the options are endlessly variable, but what follows are some short clips (around 30 seconds long) from the beginning of Scotland The Brave (my request, as familiar to many: but we did record a couple of other tunes too), covering the main options.

Another view of the band set up in two opposing arcs.

Starting off, here are clips from the recordings of the band arranged in two opposing arcs:

First, we have fig 8 mid-side with the two MKH 8030 mics, which, of course, decodes to a Blumlein pair:

The stereo imaging is good for this, but the bass drum is very light. Looking at this in an FFT frequency spectrum analyser (Voxengo SPAN), the fundamental of the drum is around 35Hz, so the lack of low end in the MKH 8030 (whilst unusually good for a fig 8) is rather exposed. With a coincident omni in the array we can add this in a variety of ways, but just to keep things straightforward here is the same clip above with the bottom end of the omni MKH 8020 mixed in (with a 100Hz low-pass filter) at -6dB.

So now moving on to the omni mid-side pair itself, which, of course, has no problem with the bottom end of the bass drum. As you would expect, the drums have swapped sides (most obviously the snare is now on the left as it was in reality) as this and the subsequent clips don’t have the flipped LR stereo of the rear side of fig 8 MS and Blumlein pairs:

Leaving the various outputs of the native B-format array for the moment to compare omni-based recordings, here is the omni AB (spaced pair) of Rycote OM-08 mics at 840mm spacing (the spacing chosen to match the stereo recording angle of the Blumlein pair, decoded from the fig 8 mid-side pair, which lay behind the two opposing arcs formation):

Next up we have double mid-side. This uses forward and backward cardioid mid mics (created by mixing the omni and forward-facing fig 8 in the native B-format array) with the two resultant cardioid mid-side arrays mixed at the same level:

This might well be fine with the full band (and the low end is certainly present, due in no small part to the fact that the cardioids are created from a mix of the forward-facing fig 8 MKH 8030 and the MKH 8020 omni, so, as my preparatory tests demonstrated, have a better bass response than the MKH 8040 cardioid), but the level of the very small drum section is a bit low. Of course, we can change independently both the polar pattern of the two mid-side arrays that make up a double mid-side array and, more relevant here, can change the relative levels between the front and the rear. So here is more of the same, but with the rearward-facing component of the double mid-side array 6dB louder than the front:

And to demonstrate this flexibility a bit further, here is the double mid-side array again, but with the rearward-facing component of the double mid-side array 12dB louder than the front:

And then in a full circle, with a tighter radius.

Moving on, here are clips from the recordings of the band arranged in a full circle. Again the clips comprise the opening part of Scotland The Brave.

As before, first off we have fig 8 mid-side with the two MKH 8030 mics:

This still lacks the bottom end of the bass drum as with the fig 8 mid-side recording of the two arcs, but I must admit that the effect of the full circle (i.e. not avoiding direct sound from the side, with the consequent phasing issues arising from the fact that such sound is picked up by the front of one capsule and the rear of the other) is much less noticeable than I thought it would be. Perhaps that’s just my ears (I have been listening to a lot of bagpipe recordings over the last few days)! Anyway, I think it might still be one to steer away from and, accordingly, I haven’t included a version of this clip with added low end from a low-pass filtered omni mic.

On then to the omni mid-side pair, which, as before, has no problem with the bottom end of the bass drum. Again note that the drums have swapped sides (most obviously the single snare is now on the left as it was in reality) as this and the subsequent clips don’t have the flipped LR stereo of the rear side of fig 8 MS and Blumlein pairs:

Here is the omni AB (spaced pair) of Rycote OM-08 mics at 460mm spacing (i.e. narrowed from the previous 840mm spacing to give the wider stereo recording angle required for the full circle: 180 degrees):

As noted in the two opposing arcs set up, the drums in the double mid-side recording here are a bit on the quiet side, reflecting the lack of tenor and side/snare drums, although, perhaps counter intuitively, they are clearer than in the equivalent recording with the two arcs, despite the pipers spreading into the rear half of the full circle. As noted before, we can change, independently, both the polar pattern of the two mid-side arrays that make up a double mid-side array and, more relevant here, the relative levels between the front and the rear. So here is the same as before, but with the rearward-facing component of the double mid-side array 6dB louder than the front:

And to demonstrate this flexibility a bit further, here is the double mid-side array again, but with the rearward-facing component 12dB louder than the front:

High-frequency loss with vertical omni

As mentioned in part 1 of the blog post, omni mics are increasingly directional with high frequencies, which is the main reason to orient the mic vertically in the native B-format array if dealing with a sound source in a circle rather than, more typically, largely in front of the mics: that is, to ensure an even response in the horizontal plane round the full 360 degrees. But, of course, it also means that this approach reduces the high-frequency response (albeit equally) in the horizontal plane. As I said in the section on mic arrays, I didn’t expect that the high-frequency losses would be hugely significant with a pipe band: indeed, it could be useful given the nature of bagpipes and snare drums. I certainly don’t feel that results are weak in that regard, but, for the sake of completeness, here is a clip of the omni mid-side recording of the band in the full circle, with the omni mic given EQ to compensate as per Sennheiser’s polar plot for the MH 8020:

Processing

The native B-format array offers a lot of flexibility, which is only partly explored in the already rather numerous clips provided above. These have all been produced manually in Reaper, albeit using a mid-side plug in for the MS processing. Further tools can aid the process, be that Schoeps’s double mid-side plugin or, more usefully, plugins that can use the WXY tracks of the native B-format directly. So finally, here are the WXY clips (for both the opposing arc and the full circle set ups) for anyone who wants to play with them in an ambiosonic audio processor such as the Soundfield by Rode plugin, with which I have had fun dabbling.

The verdict?

Well this may be too early to call, given that this recording session was designed to be the first of two tests to compare indoors vs outdoors recording of the pipe band. The outdoor session will probably have to wait until September, due to holidays and a flurry of summertime engagements for the band, and then we will have to juggle the vagaries of the weather. But, even before this second test, I must confess I am much happier with recording the pipe band indoors than I was beforehand: I was very much in the ‘record a pipe band outside’ camp (indeed, perhaps the only voice in this case!). The set up in the abbey worked extremely well from my perspective: OK, the part-band was imbalanced in terms of pipes vs drums (and, indeed, imbalanced within the drum line with just one tenor and one side/snare), and there are some tweaks that I would like to make when we have a fuller drum line (e.g. bringing the tenor drums forward of the snare/side drums), but the acoustic was excellent and vastly different to the practice room.

And, beyond that, this first session has been extremely useful for assessing the different means of recording the band in a circle or in a broken circle of two arcs: I am happy with both formations although, of course, the different mic arrays performed differently in the two configurations of the band. The omni AB, or spaced pairs, worked reasonably, but lacked clarity on the snare drum so would require extremely careful placement of band members to get the (baked-in) balance right, if possible: in the context of a loud pipe band with members understandably not used to protracted setting up for recording and the lack of really good (and isolated) monitoring on location, I would be loathe to go down this route. This isn’t unexpected, as I included the spaced omnis as something of a control in this test. The native B-format array was a great success in giving so many options from a three mic set-up, and producing what I think is the better sound. Using the two fig 8 MKH 8030s alone, as a fig 8 mid-side pair, underplayed the low frequencies of the bass drum, understandably, but, as we have seen (or, rather, heard), this can be supplemented by a bit of bass from the omni MKH 8020 mic. Again using just two mics, the omni mid-side (MKH 8020 and MKH 8030) pair gave a good result in both the opposing arcs and full circle arrangements. The (virtual) double mid-side array from the three mics, however, is my preference: while sharing the ability to vary the levels of front and rear with a conventional double mid-side array (say made with two cardioids and a fig 8), the fact that in this case it was derived from the native B-format array gives it additional advantages. First, it keeps the low end intact (by virtue of the increased low-frequency response of the two virtual cardioids made by combining the MKH 8020 and forward-facing MKH 8030). And, second, it has complete flexibility in post in terms of the polar patterns of the mid mics. Playing around with all this is certainly easier in something such as the Soundfield by Rode or Harpex-X plugins, and they make steering the mic arrays (not that useful in this instance) easier too. In short, I’m really impressed by the MKH 8030 and MKH 8020 native B-format array for recording musicians in a circle: I suggest that it is worth giving something similar a go if you have a comparable challenge and suitable mics to hand.

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A tale of two MKH 8030 mics, a native B-format array and a pipe band. Part 1: the mic arrays.

August 4, 2024

Some of the members of the City of Norwich Pipe Band at Wymondham Abbey for the recording test.

Introduction

A happy coincidence of an interesting recording project and the arrival, a few weeks ago, of a second MKH 8030 fig 8 mic from the folks at Sennheiser set me thinking. The recording was to be of the City of Norwich Pipe Band: that is bagpipes and drums (side/snare, tenor and bass). Pipe bands often play in a circle, so they can all see each other, and for this recording the plan was to maintain that approach in broad terms. The circular formation, with the band members’ backs to any audience has given the BBC’s sound engineers a challenge when recording the world pipe band championships outdoors in Scotland each year. At that event they are obliged to record outside the circle formed by the band (who, to make things yet more complicated for recording, march forward while playing before forming the circle), making the best of a difficult situation. For this recording, which was not in the context of a competition or, indeed, a public performance, I had the advantages of a static pipe band, being able to place mics inside the circle, and, also, being able to tweak that circle idea a little bit.

Both the recording of a pipe band and the recording a group of musicians in a circle, or near circle, are challenges, and in this case extra complexity was introduced since the overarching aim was to do two test sessions, one inside and one outside, as a prelude to possible recording of a CD (opinions generally are a little split on whether a pipe band should be heard/recorded indoors or, in its more natural habitat, outdoors). Rather than one overly long write up, I am breaking this down into separate blog posts: this first one explores the mic arrays used, and the second discusses the recordings from the indoor test (and includes samples of them).

Options for recording musicians in a circle

There are various ways to tackle recordings of a circle of musicians, with the end results ranging from mono to surround sound: in this case we were after stereo. Obvious options for such recordings would be a Blumlein pair or mid-side with two fig 8s; omni mid-side; double mid-side; and a spaced pair of omni mics. The last three options would work with a full circle (though omni mid-side suggests flattening the circle a little front and back, due to less sensitivity of the back-to-back cardioid pattern of the resultant, decoded, LR stereo pair). And the Blumlein pair or mid-side with two fig 8s options suggest modifying the circle to form two opposing arcs, say of 70-90 degrees each, avoiding any direct sound from the musicians in the more difficult (i.e, phasey) side quadrants. Choosing from these options is not easy as there are pros and cons. Blumlein or mid-side with two fig 8s (which mathematically decodes to Blumlein, but which inevitably sounds a little different) offer the prospect of excellent stereo imaging, albeit with the reversal of the rear side (not an issue in this or, indeed, many situations); omni mid-side and spaced omnis offer the prospect of a better low end (relevant here to the bass drum); and double mid-side offers the scope of having different mid-mic polar patterns front and rear and, more significantly, the option of changing respective levels in post (useful for tweaking the balance of the drums and the pipes on either side of the circle). Well, given that this was to be a test recording, the obvious solution was to do all of these options simultaneously. This didn’t require a proliferation of mics vying to be in the same place at the same time, but, rather, a simple set up of three mics in a pantophonic (i.e. horizontal, or 2D) native B-format (WXY) array for all the coincident mic options, flanked by a pair of omni mics to cover the spaced-pair option. So five mics in total.

Spaced pair

The spaced pair of omnis option hardly needs much explanation, as it will be familiar to most, if not all, readers: the key points here being aiming the mics upwards to get an even sound in all horizontal directions (omni polar patterns being increasingly directional at higher frequencies), deciding on setting the height (with no musicians behind others and wanting to get a balance between upwards projecting drones at the rear of the pipers and downwards pointing chanters at their fronts, and to avoid over dominance of the snare drums (or, in the first test, single snare drum), I settled on 1500mm), and choosing a spacing. For the latter, with the full circle I wanted a stereo recording angle (SRA) of 180 degrees, so that meant a spacing of 510mm or less: I went for 460mm. For the two arcs, however, it made sense to narrow the SRA to match a Blumlein pair (i.e. 76 degrees) so that meant a spacing of 840mm. And for the mics, not having two more MKH 8020s, I settled on a pair of Rycote OM-08 mics.

Coincident arrays: Blumlein, mid-side, double mid-side, and native B-format

The native B-format set up is likely to be less than familiar to many readers. B-format components (W, X, Y and Z) can be derived from the A-format outputs of the tetrahedral (or, indeed, octahedral) arrangements of ambisonic mics, such as the Soundfield. With ambisonic mics, the W, X and Y components (we can dispense with the Z or height component here as irrelevant to our stereo end product) are derived from combining the different capsules, creating three virtual mics – forwards and sideways facing fig 8s (X and Y respectively) and an omni (W). A native B-format set up, needless to say, just uses two real fig 8 mics and a real omni mic. The combination of mics allows all of the planned coincident arrangements to be achieved and, indeed, allows the array to be steered: perhaps not that relevant in this case, though this could be handy for some circular set ups. The native-B array, which today can be found in single mics such as the Josephson C700s (for a cool £7,600), was pioneered by Dr John Halliday at Nimbus Records and is often referred to as the Nimbus-Halliday array: the two fig 8s (vertical and end-to-end) are separated by a forward-pointing omni mic. Such an arrangement wasn’t ideal for the purposes of this test: first off, in the Nimbus-Halliday array the omni is facing forwards, so the sound will be different from the rear; and, second, the mics aren’t as coincident as they could be (thinking here of comb filtering that will concern the purists) for some of the two-mic options first envisaged for this pipe band recording. For example, the two fig 8s, if used for mid-side, are separated by the omni mic, which would result in 54mm centre-to-centre spacing with two MKH 8030s: better than 68mm with a pair of MKH 30 fig 8s, but far from ideal. Taking suggestions by Daniel Courville and Paul Hodges of swapping the omni with one of the fig 8s (to remove the directionality of the omni mic at high frequencies) helps, but this can be much improved by rotating the whole array by ninety degrees, which swaps the orientation of the two fig 8s. This then gives a spacing of the omni and forward-facing fig 8 of 16mm centre-to-centre: very effective when combining these two mics to make a cardioid or, in different proportions, any other polar pattern for the mid mics in double mid-side. And the two fig 8s (thinking of mid-side with two fig 8s) become set at 27mm centres (half what they would be in the Nimbus-Halliday array if using the same mics); and, finally, the two most distant mics, the omni and side fig 8 (for omni mid-side) are at 43mm centres. Turning the omni vertical evidently reduces the high-frequency response in the horizontal plane a little, but, if required, a little high-frequency lift could be added. I didn’t anticipate this being much of an issue with bagpipes and snare drums: a little reduction in such frequencies could well prove useful. In terms of elevation of the array, this followed the height and rationale of the spaced pair.

Spot the difference! Left: the conventional, or Nimbus-Halliday, native B-format (or native 2D first-order ambisonic) array, which, top to bottom, comprises Y, W and X. Right: the revised version that I used, which, top to bottom, comprises Y, X and W. I used some thinner cables in the final version, not least as it made aligning easier when using shockmounts.

Taking the array outside: wind protection

With the pipe band test sessions being planned to determine whether any full recording session(s) for a CD should be recorded indoors or outdoors, the native B-format array needed to fit in a windshield. Inspired by ex-BBC sound recordist Roger Long’s experiment with a version of the Nimbus-Halliday array with the three mics (two MKH 30 and one MKH 20) all set vertically in a single suspension (the fig 8s side-by-side, and the omni in front), it is easy to rig the smaller MKH 8000 series mics in such a way as they fit into a normal blimp, which I duly tested (see photo below).

A very compact option for the native B-format array, fitting inside a standard windshield (in this case, a Rode blimp mk 1). I’d have been happy enough using it as shadowing effects and, indeed, any comb filtering arising from the non-coincidence on the horizontal plane are much exaggerated by the theoreticians that plague recording forums, but, given that I could fit the larger and nearer to ideal array into my DIY blimp, I decided against it for this project: but one to test more in the future perhaps as it is certainly much easier to manage in the field.

But given that use of the array in that set up means that the mics are not so well aligned in the horizontal plane, and that some will argue that acoustic shadowing results (always more theoretical than real), I thought it was just simpler and more consistent to use the same larger and more ideal array indoors and outdoors, taking advantage of my massive DIY blimp, originally built for LDC mics. A couple of welded additions by my ever-helpful friend Rob Moore, who built the original blimp basket, meant that the blimp was ready for my native B-format array.

And here’s the larger native B-format array inside my massive DIY blimp, originally built to accommodate an LDC mid-side pair for those occasions when extremely low self-noise is required: a few minor adaptations needed (thank goodness for its adaptable stainless steel construction).

Now by this point some readers may be wondering why I didn’t simply use an ambisonic mic. Well, other than not owning one and wanting to achieve a flexible approach with the excellent mics I am fortunate enough to own already, the key point is that the recording was not for surround purposes, but chiefly to determine the best approach for subsequent recording of a CD that is quite likely to involve a simpler approach. And, like many others, I have yet to be persuaded that the cheaper capsules in at least the more affordable ambisonic mics are in the same league as those of the MKH 8000 series mics. My biggest fear about the native B-format array was that the combination of mics – especially the combining of the omni and fig 8 – would fall well short of other MKH 8000 mics designed with a particular polar pattern. So at the planning stage I tested this by rigging an MKH 8020 omni and MKH 8030 fig 8 alongside an MKH 8040 cardioid, to compare virtual cardioid and actual cardioid mics. The consistency was remarkable, with the only audible difference to my ears being the slightly increased bass component of the virtual cardioid (not surprising: the MKH 8040 is no slouch in terms of bass, but it still lacks the bottom end of a pure pressure omni). So, happy with this key test, and with a workable native B-format rig, it was time to record: see part 2 of this blog post, for the first (i.e. indoor) recording session and results.

Top to bottom: MKH 8040 cardioid, MKH 8030 fig 8, and MKH 8020 omni. A simple test rig to compare the sound of the omni + fig 8 (mixed at 50:50 creating a cardioid) vs a purpose-built cardioid. This sort of virtual polar pattern creation is at the heart of the rig I was proposing, so thought a simple direct mono comparison like this a useful reality check before committing myself to recording with the native B-format array. The actual and virtual cardioids sound remarkably similar, although the additional bass response of the omni means that this is evident in the virtual cardioid: a high-pass filter could always reduce it if needed, but with the bass drum of the pipe band I thought this would be useful (as, indeed, proved the case). Changing the proportions of fig 8 and omni in the virtual mic means all polar patterns between fig 8 and omni can be created.

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Sennheiser MKH 8030 part 4: comparing it to the MKH 30

May 7, 2024

Two mid-side pairs for size comparison: MKH 30 and MKH 50 (left) with MKH 8030 and MKH 8050 (right).

This is turning into something of a marathon, with the latest installment of the Sennheiser MKH 8030 fig 8 mic tests comprising a comparison with its older MKH counterpart: the MKH 30. The latter was introduced back in 1987 and is still in production: quite what Sennheiser’s plans are for the mic, now that the MKH 8030 is starting to appear in retailers, I simply do not know, but some of the other earlier MKH range have dropped out of production (MKH 20 omni and MKH 40 cardioid). Whether the MKH 30 continues to be made for years or not, recordists will wonder: just how does the new fig 8 compare? As with all the MKH 8000 series mics there are the obvious physical differences of size; the new series being modular; and the earlier range having built-in switchable high-pass filters and pre-attenuation (vs this only being available via the additional MZF 8000 module – now just updated to the MZF 8000 II). And then there is the extended high-frequency response of the MKH 8000 mics. But just how different do the two fig 8 mics sound? I was certainly interested in this question, and have been receiving queries from others similarly wondering, so armed with an MKH 30 and, to allow some MS comparisons, an MKH 50 (still in production, by the way) sent by the folks at Sennheiser, I set to for some comparisons.

The sound of silence

First off to compare is the sound of the two mics recording nothing: their self-noise. Both are specified as 13dBa, but self-noise rarely sounds the same between different makes or even ranges of mics and with the known very different frequency response above 20kHz, there was every reason to suspect there might be subtle differences as, indeed, there are between the other MKH 8000 polar patterns and their older MKH counterparts. So into the airing cupboard, under duvets and towels, went the mics and off went the electricity for my usual home-brewed and very much not laboratory conditions for comparing self-noise. As for the self-noise tests in part 1 of the MKH 8030 tests, I used a 100Hz high-pass filter since it was impossible to keep out the very low frequencies.

Here are the spectrum analyzer visualizations of the noise, with gain cranked up:

MKH 8030 with 100Hz high-pass filter: scale 100Hz to 48kHz.

MKH 30 with 100Hz high-pass filter: scale 100Hz to 48kHz.

As expected, the self-noise looks wildy different, but, of course, most of this is the increased self-noise in the MKH 8030 over 20kHz (i.e. above human hearing). In the audible part of the spectrum, the two are pretty comparable, although the gentle dip between 1kHz and 6kHz is a little deeper (by a couple of dB) with the MKH 30, which translates to the self-noise of the MKH 8030 being fractionally more noticeable. But we are splitting hairs here: both mics have remarkably low-self noise for SDC fig 8s and there is nothing of concern with the new design vs the older one on this front.

Bat recording at dusk in Guestwick Church.

Bats in the belfry…or not

One of the distinctive features of the MKH 8000 series is, indeed, the extended frequency range. You can see this in spectrograms of many a recording where frequencies above 20kHz are present: the specs cite a 50kHz upper limit vs 20kHz for the MKH 30. Taking this to extremes, I went with Norfolk-based ecologist, Danny Cotgrove, to Guestwick Church at dusk, comparing the MKH 8050/8030 and MKH 50/30 mics: obviously an unfair comparison, but it was an interesting evening nonetheless. I was particularly impressed by seeing Danny’s Batlogger M2 in action (evidently the right tool for the job), but that’s another story. There weren’t a lot (a ‘cauldron’?) of bats in action, but just the odd one: common pipistrelles and some Myotis bats (probably Natterer’s bats), apparently. Here are a few short clips, slowed down to 25%.

The bats are much clearer in the MKH 8050/8030 MS pair than in the MKH 50/30 pair, as expected, but the self-noise of the MKH 8000 mics at such high frequencies is distracting. Obviously, to get usable audio from such quiet ultrasonic sounds requires some hiss removal, so here is a very quick and dirty example using RX De-noise:

And here are the spectrograms for the two fig 8 mics:

Spectrograms of a clip of the bat recordings (as originally recorded), with MKH 8030 (left) and MKH 30 (right): the vertical axis extends to 96kHz, and the clearly visible (red) spikes of the bat sounds in the upper halves of the spectrograms range from around 46kHz to 76kHz.

Up in the belfry of Norwich Cathedral risking my eardrums…again.

At face value, the bat recording example might seem as if it leads to a dismal conclusion: i.e. the MKH 8030 has much higher frequency capability than the MKH 30, but the price of raised self-noise is too high to pay. But bear with me. With a touch of irony, I headed off to the cathedral belfry, not for more bats but for a (very) healthy signal of an audible sound with extended high frequency overtones: the bells, the bells! The spectrograms show that the sound extends above 48kHz, but of more use are the sound files.

Here we have the original unmodified (mono) recordings with the individual fig 8 mics:

And here we have the same two clips slowed down to 25% (just as I did for the bat recordings), as if playing around for sound design: reassuringly there is no distracting self-noise – a consequence of a healthy sound signal – and there is no need for noise removal.

So, yes, the MKH 8030, like its siblings in the same series, has extended high-frequency that can be useful and is something that the MKH 30 and its siblings don’t offer to this degree, but, with quiet signals, it will need much care and some de-noising. Whether or not this capability matters to the sound recordist is a different thing altogether: for many, if not most, a frequency response over 20kHz is simply not needed.

It’s all about that bass

Down at the other end of the frequency spectrum the specs for the two fig 8 suggest that the MKH 8030 goes a bit lower: the frequency response graph of the MKH 30 cuts off at 40Hz, though, so it is hard to tell from this how it compares with the MKH 8030 below this. Turning to my quick and dirty low-frequency source, I stuck the mics by the exhaust pipe of an idling car engine, and this showed that the MKH 8030 does indeed have more low end that its older counterpart.

Here are the sound files:

And here are the spectrum analyzer visualizations of the exhaust recordings:

The most distinct feature is the level of the fundamental (26.4Hz), which is c.4.5dB louder with the MKH 8030 vs the MKH 30. This is not to say that the MKH 8030 oddly emphasizes bass: as we saw in part 1 of the MKH 8030 tests, similar tests with another car exhaust saw the MKH 8040 measure 9dB more than the MKH 8030 at the 22.5Hz fundamental. Now, just as with the high-frequency extended range, some may not find the increased low end of the MKH 8030 vs the MKH 30 especially useful, but I suspect many more will, for music recording and bass-heavy ambiences and sound effects amongst other things. I’m certainly one of the ones who is glad to have a bit better low-frequency performance. And if you don’t want it, its easy to roll off with a high-pass filter in your mixer/recorder or via the MZF 8000 ii filter module.

I suspect this view is getting rather familiar to some readers of this blog…

In the field

The robust and, above all, humidity-resistant nature of the RF-based MKH mics has made them favourites for recording in the field, be that production sound or field recording, so I moved on to record some ambiences. As usual, nothing very adventurous: you don’t need a long-haul flight and a rare species to test a mic in the field (though doubtless a rain forest would provide some nice humidity), so, as I have done so many times before, I ventured a few yards further down my drive from the car exhaust test to record the sounds of early May in my quiet Norfolk village street. Sorry if you are getting bored of listening to my village street, but cheer yourself up with the thought of how environmentally friendly this is! And it always gives a good mixture of sounds: birdsong, passing cars, the odd sound of a distant shotgun (or is it a bird-scarer?), and whatever the neighbours are up to: a bit of landscape gardening this time.

There are two sets of recordings: first off, we have the two fig 8s together, rigged with back-to-back clips in a single Rycote Cyclone, and facing the road;

Then, second, we have two separate windshields each containing a mid-side pair with each fig 8 paired with its super-cardioid sibling. Obviously the different qualities of the two mid-mics comes into play, but as an MS side mic is how most field recordists use the MKH 30 and how most will use the new MKH 8030.

Luke Chapman in his workshop, playing a bit of guitar into an MKH 30 and MKH 8030.

Down in the workshop

Moving inside again for some musical tests, I tootled down the back lanes to the workshop of woodcarver and musician Luke Chapman. Luke was happy to put down his chainsaw (well, actually he was re-spraying his Land Rover chassis when I arrived) to oblige again with some guitar playing, and the sets of recordings comprise mono recordings with the two fig 8s (which I rigged end-to-end, pointing at the twelfth fret from about 600mm/2ft away) and then mid-side recordings with the MKH 8050/8030 and MKH 50/30 pairs, a little further back (to get a bit more ambience into the recording: you can really hear the rooks outside trying to join in). There has been no processing (compression, equalization, addition of reverb etc.) of the recorded sound. The mono recordings with just the two fig 8 mics aimed towards the sound source are perhaps the most informative, although, again, the MS pairs show how the two mics sound with one of their respective siblings as the mid mic. I’m sure some will hear (or at least imagine they hear!) significant differences, but, to me at least, the two fig 8s sound remarkably similar.

Here are the two recordings of the fig 8s on their own:

And here are the recordings of the two MS pairs:

And here’s a video of the guitar test recordings – both the mono comparisons of the two fig 8s, and then the two mid-side rigs – cutting from one mic/pair to the other.

Conclusions

These few tests just skim the surface of comparisons between the MKH 30 and MKH 8030. With the other polar patterns of the two MKH ranges of mics, there have been recordists who prefer one to the other: or one vs its equivalent for a particular purpose. Evidently there are some subtle nuances and preferences, with these varying in relation to a wide gamut of sound sources, that are beyond the scope of the necessarily simple tests here: such discerning recordists will want to get both mics in their hands to compare them in their typical uses. But with that caveat, my experience of using the two mics is that the MKH 8030 occupies a similar position to the other MKH 8000 mics compared to their equivalents in the older MKH series: as such it lives up to the well-deserved reputation of the MKH 30. Just as with the other MKH 8000 series mics, it doesn’t render the older MKH fig 8 redundant: far from it. If you need a very low noise SDC fig 8 with demonstrable ability in high humidity and that sounds top class, then both of the Sennheiser fig 8s are likely to be at the top of your list: if you also want a very small SDC and one where there is a full range of mics in the same series currently in production, then, obviously, your choice out of the two will be the MKH 8030.

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Sennheiser MKH 8030 part 3: mid-side field recordings

April 6, 2024

Squeezing four mics into a blimp suspension for mid-side testing. Top to bottom: MKH 8040 (cardioid), MKH 8030 (fig 8), MKH 8020 (omni: right), and MKH 8050 (supercardioid: left). The acoustic shadowing (which is inevitable to some extent in coincident pairs) of this cluster of mics near each other has very little effect in reality, and is largely a concern of the theoreticians out there: much more important is the ability to be able to compare different flavours of mid-side recording at the same time. Despite some snazzier options, my old Rode Mk 1 blimp again proved the best bet for accommodating such a number of mics.

Introduction

Part 2 of the Sennheiser MKH 8030 (fig 8) tests involved recording a bluegrass band with a mid-side set-up, focused on the Sennheiser MKH 8040 (cardioid) and MKH 8030 pair, but including the Rycote BD-10 (fig 8) and CA-08 (cardioid) mics. For the next series of tests I was keen to hear how the MKH 8030 sounded with other mics from the MKH 8000 series in a mid-side pair. There are, of course, five other mics in the series, ranging from omni to long shotgun, but, to make things manageable, I wanted to focus on three mid-mic options: the MKH 8020 (omni), the MKH 8040 (cardioid) and the MKH 8050 (supercardioid). The MKH 8090 (wide cardioid) has much to commend it for a mid mic, but I suspected that the difference between it and the omni and cardioid mics might be a bit nuanced for my tests. Mid-side with shotgun mics is possible, of course, but it’s not something I’m hugely keen on. Besides, I needed a practical rig to be able to test different combinations at the same time, so four mics of similar size was my limit for a blimp. Similar practical matters also ruled out including mid-side with a second MKH 8030 (which would require a different orientation): that, and the fact that I don’t yet have a second MKH 8030! So tests of a fig 8 as the mid mic, and of a Blumlein pair of MKH 8030s, will have to wait until another time.

It has been very clear from the outset that the MKH 8030 is a superb fig 8 mic, condensing much of what is loved about the MKH 30 into a smaller form, so testing its performance in mid-side rigs might seem superfluous: it could be assumed that the mic will deliver excellent mid-side recordings when used with the other MKH 8000 series mics. Well, there are two angles to this: first, it’s good to check that theory and expectations are matched by reality, not least as the MKH 8000 mics are not cheap, and provide samples of this; and, second, I was intrigued by the on-line comment of another tester of the pre-production MKH 8030 mic as part of a mid-side pair, who said ‘the 8050 is too narrow and creates holes in the stereo image and other weirdness when decoding‘. This was for recording nature so narrowness may well have been an issue for desired wide ambiences, but holes and other ‘weirdness’ seemed surprising since the MKH50/MKH30 pair has long been used to good effect. And, of course, a supercardioid or hypercardioid mid-mic choice is an obvious one for production sound recordists (i.e. heavy users of mics with these polar patterns) who want the scope for a bit of mid-side stereo when the occasion arises.

So to these latest tests. Given the comment about the MKH 8050 as a mid-mic, and the previous musical test for the MKH 8030, I have this time focused on field recording – both natural and man-made sounds, and including sounds that cross the stereo field: hopefully, these will allow consideration of any holes in the centre of the stereo image, or other ‘weirdness’. In each of the samples below, the recordings are as straight off the recorder, albeit with levels adjusted in post so that the mid and side mics are mixed at a ratio of 50:50 (I recorded all four channels with the same gain) to reflect the slightly different sensitivities of the mics: i.e. MKH 8020 at -30dBV, MKH 8030 at -30.8dBV, MKH 8040 at -34dBV and MKH 8050 at -34dBV.

Mid-side test rig in blimp, recording the not-quite-as-quiet-as-you-might-think village street sounds.

‘The Deserted Village’

First up, is my old and unadventurous stalwart: mics at the front of our garden, at ninety degrees to the street in this quiet Norfolk village, with birdsong and the odd passing car or tractor.

‘Sea-Fever’

Next I took the four-mic MS rig up to the coast. There was a gentle offshore wind, but the shingle beach shelves steeply, so there was some wave action nonetheless. Waves break onto the beach at different times, naturally, so the sound often moves across the stereo image. For this first series of recordings the mic stand was rather near to the sea than in the photo: it was right at the water’s edge – so much so that a couple of times I had to grab the stand and stagger backwards to avoid a clutch of Sennheiser mics taking a dip in the North Sea.

And then, while on the beach, but, say, 30ft (10m) from the water’s edge, I recorded myself walking past the mics, angled downwards a bit, again with the intention of exploring the ‘hole in the middle’.

At Holt station, on the North Norfolk Railway, set up opposite a little saddle-tank locomotive built for, and named after, the British Sugar Corporation’s factory at Wissington (near Downham Market): this is still sugar beet country.

‘At The Railway Station’

A few miles away, the season was was well and truly underway at the North Norfolk Railway, with trains bustling between Holt and Sheringham over the Easter weekend. Setting up lineside opposite a small saddle-tank locomotive, with the station platform beyond, I recorded its departure and the rattle of its carriages as it headed off backwards.

Diesel locomotive at Holt station. Nice to be at the level of the track for the clatter of the wheels, or is that bogies?

After this small train pulled out, I became very visible to anyone on the platform so perhaps it wasn’t surprising that a chap pointed me out to his toddler grandson, who in response gave a nonplussed shrug way beyond his years. With headphones, a furry blimp and a camera, I must have looked like an über-trainspotter: a fair cop perhaps, but, seeking a less conspicuous position, I moved along the fence by the lineside to a point just beyond the station. There were practical advantages of a less visible location too: chatter from those at the station was reduced, I was further from the car park, and I was next to the signal, with its occasional clunking movements. I settled down to wait for the next train, which then took me unawares as there was no whistle or chuffing to announce its arrival: it was a diesel. Well, it may have lacked the nostalgic charm of steam, but it was a different sound, so I pressed record.

‘Hercules’, a 2-8-0T from the Great Western Railway, visiting Norfolk for the season. It’s doing the whizz around the run-round loop that the locomotives do at Holt (a terminus) to get to the front of the train again for the return trip, so it hasn’t got its carriages attached at this point. The manoeuvre makes for more recording options.

Working on the principle that the locomotive types must be alternating, I waited for the next one to arrive, hoping for another steam engine and perhaps something a bit larger than the little saddle tank. Sure enough, after another 15 minutes or so, along puffed a much larger tank engine, pulling a longer train of carriages. OK, not one of the biggest locomotives on this railway, but noticeably different in sound: a lot bassier, and, as expected, this comes across especially well in the omni mid-side recording. In this case I had the mics angled at forty-five degrees towards the departing train, which, of course, sees the greater emphasis from the omni mid mic on the disappearing sound around 130 off axis..

Sennheiser MKH 8000 mics meeting half-a-dozen Easy Care sheep (yes, that has got to be the most unlikely and unattractive name for a breed of sheep, even if it describes them well!).

‘The Manor Farm’

Perhaps it was thinking about farming round here when waiting for the little sugar beet ‘Wissington’ loco to set off or perhaps it was thinking about lunch on Easter Day, but for my final set of recordings I popped over to a friend’s house to record his sheep. No lambs yet, but despite the small size of the flock they put in a good performance for the mics: it’s amazing what the appearance of a feed bucket can do. Listening back, I’m surprised at the amount of natural reverb: far from anechoic. In this case the omni mid-mic brings in some less desirable low-frequency background noise and more traffic from the road (a B road, about 120 yards/metres away), but otherwise does a good job: that said, with the principal sound sources in front of the mics, I prefer the MKH 8040 and MKH 8050 mid-mic recordings.

This becomes more obvious still in the following series of recordings: some fairly quiet chickens in their pen scrabbling around and clucking quietly, while a distant road (more line 200 yards/200 metres away) and some distant agricultural machinery (a drier of some sort I think) add some less wanted background noise that is least evident – naturally – the MKH 8050 mid-side pair. Not the most exciting field recording ever made, I know, but it illustrates the point!

Conclusions

The main purpose of this post – as with so many of the other tests – is to provide the reader with a few samples to draw their own conclusions. But, beyond that, what is crystal clear to me is that there is no oddity with the MKH 8050 and MKH 8030 mid-side combination: the pair perform exactly as one would expect – and hope – of a mid-side pair with a supercardioid mid mic.

As well as demonstrating the MKH 8030 as the side mic with a range of other MKH 8000 series polar patterns (arguably those that will be used most frequently in mid-side recording), I hope this post also provides some useful examples of the impact of the different mid-mics on the stereo field, which, of course, give rise to different virtual mic patterns: the omni mid-side pair is nominally equivalent to an XY pair of cardioid microphones oriented back-to-back (180 degrees); the cardioid mid-side pair is nominally equivalent to a pair of supercardioid (often incorrectly cited as hypercardioid) microphones at an included angle of about 130 degrees; the supercardioid mid-side pair is nominally equivalent to a pair of hypercardioid microphones at an included angle of about 120 degrees. I say nominally since the equivalent microphone patterns don’t exactly match definitions for existing microphones and sound directly in front of the pair is on axis to the mid mic and, therefore, suffers less colouration than with its XY equivalent. Normally one would make mid-mic choice before recording, giving a simple two-mic mid-side pair rather than something like the clunky and impractical four-mic rig that I used for these tests.

And these tests are, perhaps, a reminder to those not so familiar with the idea, that the mid mic need not be a cardioid. In particular, the sound samples show that an omni mid mic can be an effective choice, certainly if you want, or need, the bass response of an omni mic. For field recording in particular, it offers this bass response in a much more compact form than most spaced pairs (typically involving two windshields and a stereo bar).

Indeed, you can use a mid-side pair of the MKH 8000 series mics in a small blimp: below, for example, is an MKH 8040/MKH 8030 pair in the small Rycote Nanoshield NS1-BA, which is only 220mm long. Obviously it would be much better with purpose-built MS lyres, which I hope we will see before too long, to bring the mic pair into the centre more and, thus, make wind protection much more effective. And while not a full blimp, Cinela are promising a compact COSI windshield for an MKH 8030 mid-side pair, having demonstrated a prototype at IBC 2023. In short, small and light windshield options will be available to take advantage of the small size of the mid-side pairs, for those occasions when larger windshields – with their better wind protection – are not needed or wanted.

How small and light can you go? MKH 8040 and MKH 8030 mid-side pair in a full blimp 220mm overall length: the Rycote Nanoshield NS1-BA.

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Sennheiser MKH 8030 part 2: mid-side recording

February 10, 2024

The Time and Mercy Band, comprising (left to right) Richard Ward, Jason French, Rob John and Kevin Burton.

Thursday evening was an inauspicious time to be heading out for a recording of a bluegrass band: it was a soggy wet evening here in rural Norfolk, with the narrow roads full of potholes lurking below rivers. It didn’t feel much like the Appalachian Mountains. Was it left, right, left, right, left and right again on the maze of roads around Mannington and Wolterton, or the other way round? And if I didn’t remember my left from my right, how on earth would I remember how to connect up the mics for some more mid-side recordings, building on my earlier comparative tests of the new Sennheiser MKH 8030?

I was heading back to The Forge, the studio of Kev Burton, where, a few months ago, I recorded Lucy Grubb and her band using a Blumlein pair of Rycote BD-10 fig 8 mics. This time it was a similar venture: a different band (albeit with the common factor of Kev on bass) – the Time and Mercy Band – and with a mid-side pair instead of a Blumlein pair. This was partly driven by only having a single pre-production Sennheiser MKH 8030 fig 8, but, also, because I wanted to test further the MKH 8030 in combination with the MKH 8040 cardioid as the mid mic, and throw the new Rycote BD-10 fig 8 and its cardioid (CA-08) sibling into the mix. Back at base, I’d decided that to compare the four mics in a mid-side array and allow any combination (but always using an immediately adjacent pair as mid and side mics), I needed a vertical array of five mics: that was BD-10 top and bottom, MKH 8030 in the middle, and the two cardioids between the three fig 8s. Getting them close together (I managed 4mm apart, which is better than many a back-to-back clip) was tricky and meant I couldn’t use individual shock mounts: but still wanting some isolation from a wooden floor and anticipated tapping feet, I then bolted the whole array to a pair of hefty (Duo Lyre 68 shore) Rycote Invision shock mounts, and, for belt and braces, put the stand on foam pads.

Heath Robinson would have been proud of this…

It was a little easier setting up than with the Blumlein recording, this time having all the musicians on one side of the mics and having no drum kit to manage in a fairly compact studio, but the principle remained very much as before – needing care to balance the different instruments and voices – for which having the studio’s control room, with its wonderful Midas desk (originally made for Frank Zappa) feeding into Logic, and Kev’s experience with it, was invaluable for reviewing each take. The primary feed from the mics was, again, to my field recorder.

We recorded three songs, but, for the purposes of this post I am going to focus on one, which the band call ‘Sugar Honey Babe’. It’s a traditional bluegrass song and has been recorded with many similar titles (and, of course, variations in the lyrics), and perhaps is most well-known nowadays as ‘Red Rocking Chair’.

OK, that’s more than enough preamble: to the results! First off, here’s a very quick and dirty video: one camera stuck on a tripod pointing towards the band and with the mics largely blocking the view of Rob on banjo. My excuse is that the focus was on the audio. The video switches between the various mic combinations and, as the previous tests showed that the two Rycotes are lighter in the bass department than their MKH 8000 series counterparts, a few options where the BD-10 and the CA-08 have some EQ: imperfectly applied, no doubt, but it reduces some of the more obvious differences between the mics. Other than the EQ on these few clearly labelled snippets, all the sound is as it was recorded: no reverb, no compression etc.

For those wanting to listen to the sound files without whatever YouTube does to them, here they are. I’ve not included the EQ’d versions as I am sure others can do better, or would at least want to try. These LR stereo files can, of course, be decoded back to the original mid and side channels, should you so wish (I’ve enabled downloading permissions on SoundCloud for them).

I’m not sure all the versions of the tracks with the Rycote mics given some EQ (as used where flagged up in the video above) merit inclusion, but here is just the one – the recording with the MKH 8040 and the EQ’d BD-10: although the EQ is fairly rough and ready, it does show the potential, should you wish it, to bring the mic nearer the MKH 8030.

And, finally, for a bit of fun, here’s a version of the video with the MKH 8040 and MKH 8030 pair throughout, rather than chopping and changing mic pairs. I’ve added a little reverb to this version.

So the verdict this time? As with the Blumlein pair recording, that’s one for others perhaps. The balance of the recording is far from perfect: we didn’t have endless time to fiddle around with placement, and, even if we had spent hours on it, it would have been hard to balance, say, Rob’s backing vocal and his (much louder) banjo. On a different note, rain can be heard on the studio window too: so not ideal. But putting the MKH 8030 into more real-world action with a largely acoustic band (there was a little bit of amplification for the bass) was useful, not least seeing how it performed with the MKH 8040 and just how much difference was noticeable when swapping out to different (and less expensive) mics, and what a bit of EQ might do to that. As before, my take is that the MKH 8030 is a first-rate mic, pairs well with the excellent MKH 8040 (as entirely expected), but that the considerably cheaper BD-10 is decent too and that, with some EQ, comes much closer to the MKH 8030 – especially when used as the side mic in a mid-side recording. As I’ve said before, it’s good to have these two new choices in the limited field of SDC fig 8 mics: happy days!

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