Sennheiser – Page 2

ORTF in a Mini-ALTO? Part 1: design

April 28, 2025

Introduction

The long-awaited Mini-ALTO windshields are rolling off the production line as fast as Radius Windshield’s small team can manage and are evidently going down a storm. As readers of this blog know, I’ve been playing with the Radius hoops since introduced and, more latterly, the pre-production Mini-ALTO 115 windshield (which I tested here). With the latter, my first thought was to stick a mid-side (MS) pair inside it and then, for a bit of fun, a double mid-side array. Well, the slightly mad schemes – at the opposite end of the spectrum size-wise from my DIY Mega-Blimp project – continue. In this case, the project began when John and Simon at Radius asked if I could squeeze an ORTF rig into a Mini-ALTO: not as a commercial commission, I must hasten to add, but just knowing I like a challenge and am always up for esoteric mic-mounting solutions. My first reaction was no, but thinking on it more – and having been rather immersed in ORTF lately (or, rather, an eight-mic ORTF-3D rig using Nevaton mics) – I decided to have a go.

The design problems

Straight off the bat there seemed two main issues. First, there was the common problem for anybody trying to fit ORTF pairs in a windshield: mic length means the capsules end up too near the basket edge for effective wind protection. Not for nothing did Rycote make a larger diameter windshield specifically for ORTF, and a much larger diameter for ORTF was one of the reasons behind my Mega-Blimp. With the diminutive 80mm diameter of the Mini-ALTO the problem is even greater than with a more standard 100mm diameter windshield. Second, the Mini-ALTOs have small rear pods and various – all longer – front pods, none of which are swappable from front to rear due to the polarity of the magnets that hold them in place: what would be needed is a longer rear pod and, ideally, matching pods front and rear. A third, more minor issue, is that the Mini-ALTOs are designed to be aimed at the subject on the longitudinal axis, so the base pivots the wrong way.

The design solutions

The solution to the small diameter of the Mini-ALTO – insofar as there could be one – was to use short mics and to offset the mic mounts from the centre-line of the windshield as far as possible. Most of the familiar small SDC mics are still too long, not least as connectors and, even when hard wired, projecting cables come into play: even the small Schoeps CCM4s seem too long once cables (and, for the popular Lemo version, connectors) are factored in, although the diminutive Schoeps CMC 1 KV preamp (with its side-exit cable) and an MK 4 capsule should fit. The Sennheiser MKH 8040, of which I own a pair, also seemed feasible, if only the short MZL connector (which can be used instead of the XLR module) didn’t have such a long rubber boot (itself over a long brass nipple) and then a cable projecting from this. Realizing I didn’t know what was inside an MZL, I worked out how to open one (OK, I just crudely levered the innards out with a penknife: but, no, it wasn’t one my precious Sennheiser MZL 8003 remote cables that I butchered!), and saw that there was scope to have a side-exit. A quick slice with a Dremel blade removed the brass nipple, and it was equally easy to drill a hole in the brass casing: 10 minutes and I had my proof of concept. I wasn’t convinced about my skills to take apart an MZL properly or to wire them up, so, in exchange for doing the slicing and drilling of a batch of forty (that was a fun lunchtime activity!), Ed Kelland at ETK Cables made up some cables for me: I suspect his right-angled custom MZLs might sell like proverbial hot cakes, if I don’t grab them all myself (the super-short MKH 8000 mics that result are really useful for all sorts of other arrays, not just ORTF)!

My working through to the shorter MZL solution, with the mics in an early iteration of the ORTF mount.

And here’s the cable I am actually using, kindly put together for me by experienced wireman Ed Kelland at ETK Cables.

With mic length sorted – or minimized as far as I could achieve using a mic commonly used for field recording and production sound – it was time to move on to the second problem. The key to mounting the mics was, of course, to keep the hoops where they normally sit in a Mini-ALTO, but have them hold a bar to which the mics are clipped. I had been doing the same for the ORTF-3D rig, so it was an obvious choice. Then it was just a matter of making various iterations of the design (thanks to the 3d-printer) until I got the right balance between keeping the capsules away from the basket edge on one side, and the keeping the back of the mics (or the customized MZLs) away from the other side. It was really satisfying that by the time I got to the sixth version (there were other changes along the way) I got the centre of the diaphragms on the centre-line of the windshield: there’s nothing magical about that (getting it back from the centre-line would have been better in such a small windshield), but at least it doesn’t feel as if the design leaves the mic capsules right up close to the basket. And clearance at the rear is enough that the mics don’t knock against the basket in normal use: I assumed that an ORTF-equipped windshield would not be handheld by a circus acrobat recording themselves in action…

The model of the bar and clips shown with the mics, giving main dimensions.

The finished design, 3d printed and tilted sideways so I could photograph it.

Rear view: you can see the ball joint I am using instead of the standard base.

End view with pod attached: the rear of mic clearance is actually better than this photo suggests, partly due to perspective, and partly because the basket narrows very slightly at the central plastic ring (which isn’t near the mics).

As for the short rear pod and unequal length of pods, Radius sorted that by getting a couple of pairs of symmetrical pods made up for these tests. That was easy – at least for me. The reason I wanted a couple of pairs is that I was concerned about the impact of the plastic ring that marks the division between the end-cap and cylindrical body of the basket. The large thick plastic ring (bigger at one end) of the dedicated Rycote ORTF windshield has an impact on the sound, and I have been concerned with the impact of large plastic elements in other designs when using mid-side pairs: for example, the chunky ring on a Cyclone has a measurable impact on the sideways-facing fig 8 mic (which may or may not matter for a recording). The Mini-ALTO end-cap rings are nothing like as chunky and such plastic elements don’t worry many a recordist, but I think it will be instructive to test the difference between a pair of shorter 90mm pods (where the end-cap rings sit inside the 110 degree angle between the mics) and longer 136mm pods (where the end-cap rings sit outside the 110 degree angle between the mics). I will cover these tests and, also, some field recording tests in part 2 of this blog post (by which time, I hope, Radius may have made a fur to fit the new windshield lengths: it will be good to compare how it performs in wind against, say, an MS pair in a Mini-ALTO 115).

Mini-ALTO baskets, top to bottom: 136mm symmetrical pair; 90mm symmetrical pair; and, bottom, my standard 115 model (the smallest) with its unequal front and rear pods.

And, finally, to the problem of the mic base pivot being oriented 90 degrees from what would suit ORTF. Well, for that I just 3d-printed a new base for the Mini-ALTO that has a 3/8″ thread and fitted it to a Gravity MS QT 1 BQuick-Tilt Microphone Adapter. A slightly clunky and chunky solution for now, but I know that Simon and Tim at Radius have been working on a small ball-joint mount anyway that will work with the Mini-ALTOs.

What is less certain is whether they will take my ORTF design and refine it into an actual injection-moulded product. I guess that will depend partly on the testing (do come back for part 2 of this blog post) and partly on practicalities and whether they think there is a market. But, even if not, just as with the other parts I have designed to fit Radius hoops (e.g. the MS clips), I will make the parts shown freely available for 3d printing: of course, this would be rather dependent on the matching pods becoming available!

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Audio Gear

Musings on mic cases…

December 9, 2024

Two very different manufacturers’ mic cases from Rycote (left) and Sennheiser (right): both have their strong points, but neither seem suited to use in the field.

I appreciate it’s a little thing, but good mic cases for use in the field are not as easy to buy as you might think. Obviously, the needs of different recordists vary: if you are a classical music recordist travelling to a concert hall or church with a mass of mics and other more bulky equipment, then, perhaps, a large Peli case might be the answer. A similar solution might also suit the smaller mic collection of a sound mixer on set, where a sound cart means that equipment is bulky anyway. But for most of my use, and I suspect that of many others, I need mic cases that take up very little space in whatever I am carrying, yet keep the mics safe and easily accessible, be this for music recording on location or field recording for ambiences or sound effects. This short blog post is for those in the same boat, especially those who have yet to find a solution that works for them: others, I am sure, will have come up with better solutions than mine, or at least ones more suited to their needs.

First off, needless to say, are the cases that come with mics from the manufacturers. These vary hugely, although few are cases you would want in the field. The Schoeps ‘Desert Island Stereo Set’ is a welcome exception, with a diminutive stereo pair of mics and mic clips (perhaps of less use) in a dinky little Peli case, and is in sharp contrast to their usual wooden cases that are not so practical or space efficient in the field. My Rycote mics have compact cases, but are for individual mics or pairs, and the bulk soon adds up when taking several into the field. Their rather nice finish also doesn’t seem quite right and robust for the field. As for my Sennheiser MKH 8000 series mics, well they come in the same massive plastic cases as the older and larger MKH mics, so again are ones to leave at home.

The Rycote mic protector case (20cm model) and one of the three mic tubes inside: although I haven’t really found the overall case great (hence the label still on it all these years later!), the internal mic mic tubes have been useful!

My first foray into mic cases for the field was the Rycote mic storage case, which looked the part: a fabric-covered tough plastic cylinder containing three plastic tubes for the individual mics. It could have been good if only the three individual plastic tubes were a comfortable fit (they were far too tight, though, puzzling, not everyone found this to be so!), and again was bulky: not bag friendly enough for me. I never really used the outer case, but have used the individual plastic tubes for some years, and I know others like similar tubes (they can be bought much more cheaply outside the audio world). As the number of mics grew, however, I found a bunch of tubes knocking around the bottom of my bag less than ideal. That said, I do find them of use for shotgun mics, which are, of course, hard to combine with other shorter mics in a single case. What I wanted was a protective case that could hold a bunch of these shorter SDC mics together, and whilst looking into what others have found (including cigar travel cases!) I had the idea (doubtless not original) of using semi-rigid cases for 2.5″ external hard drives. They come with a bit of variance in size between makes and are well-suited to a bunch of smaller SDCs. The only problem was keeping the mics separate, so they didn’t bump into each other, and for that I used lens cloths, tucking up the mics for bed before zipping up the cases. The lens cloth business is not the hassle it sounds, but it does mean that when opening the case you can’t instantly see which mic is which.

More compact SDC mic storage and transport in shell cases for 2.5″ external hard drives. Here shown with relatively long AKG Blue Line mics, but shorter SDC mics can fit across the width of such cases. The right-hand image shows how I have actually used such cases, with a lens cloth protecting the mics from each other.

So after a couple of years of this, and with some of my mics not neatly fitting into such cases or not doing so efficiently, I began to wonder if there could be a better solution. I had another good look at the smaller Peli cases, thinking about 3d-printing a tray to fit, but for my SDC mics, the model sizes just didn’t seem spot on. And that is when I stumbled across rigid cases for 3.5″ hard drives, which, being a little larger than their 2.5″ cousins, seemed the perfect size for my use. Now these vary hugely and many don’t look suited for repeated opening and closing (I guess they are for storing internal HDDs in an office or store environment?), I found some (an obscure brand!) that are more robust: really tough plastic cases, a reasonable hinge and locking clip, good seals and shock resistance (dense EVA foam), yet overall size not too large: at 172mm x 125mm x 43mm, they still slip easily into my smallest field-recording bag. With a bit of a search and you will find the same or perhaps a better model. And with a 3d-printed tray (yes, more fun with the new 3d printer!), the mics sit neatly and securely (with the perfect amount of pressure from the lid’s lining in the dense EVA foam) and I can see all the mics at a glance – like a box of chocolates. So that’s my current solution for SDC mics today and easily the best I have found. I have no doubt it will change in the future as my mic collection changes or, perhaps, when I struggle to find similar replacement cases in the future, but the basic premise will remain. As I said, only a little thing, but perhaps my musings will help someone!

Slightly bigger, rigid and sealed 3.5″ hard drive cases. The EVA foam insert at the top (I removed the bottom one and replaced it with the 3d-printed insert tray to fit specific mic models) is dense and not prone to break down easily like many foams: it applies just enough pressure to hold the mics securely in place.

And the same again, but loaded with Sennheiser MKH 8000 mics (left) and Rycote mics (right). My current solution: for how long though?!

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DIY Projects

3d printing clips for the Radius Windshield hoops

October 27, 2024

At last, mid-side clips integrated into a shock-mount, yet easily swappable with clips for a single mic.

Mid-side clip for 19mm Ø mics

When Radius Windshields launched and produced their RAD shock-mounts one of the unique features was that the mic clips could be unscrewed from the hoops and switched to something different. A radical difference from, say, the Rycote Invision series shock-mounts, where the mic clips and lyres are all one moulding. This has provided scope for Radius to produce dedicated clips for the older MKH 50 etc. mics and, ultimately, to produce dedicated MS clips, doing away with the need to use clips to fix a mic to the shock-mount then a pair of back-to-back clips to attach the second mic to the first. A fiddly faff and also bedeviled by the lack of back-to-back clips with a close spacing, which is preferable for mid-side recording. I have been encouraging Simon Davies at Radius to produce MS clips, and this is now in train using some of the ideas I have proposed. While their nice injection-moulded version is awaited, here is my version for a MS clip to fit their RAD-1 and RAD-2 hoops, and designed for 19mm Ø mics such as the MKH 8000 series and the Rycote SDC series. I should add that Simon Davies at Radius Windshields has supported me in putting this design out into the public domain, which follows similar release of their first prototype for others to 3d print (their initial design was rather different to mine, and their upcoming production version, with a central bolt and a consequently wider spacing as this is tightened). The approach I have taken with this clip is very much a product of many discussions with Simon – via email – on MS clips and other Radius items in development, but also reflective of the company’s refreshingly open engagement with sound recordists.

One of the nice things about the Radius Windshields hoops is that they fit to Rycote shock-mounts such as the InVision INV 7 here, so you can make good use of existing hardware.

CAD drawing, created using Onshape, for the MS clip.

In designing this MS clip I have gone for a spacing of 2.5mm between the mics, which is nice and close but still provides just enough room to allow two MKH 8030 mics to be inserted for a Blumlein pair of two fig 8 mics(the MKH 8030 having a wider front part to the mic). The mics are given enough grip by the springiness of the clips, and this took quite a bit of work to get right: in particular, the internal seemingly circular clips are made up of several different radii so that they hold the 19mm Ø mics properly as the necessarily undersized opening is enlarged by insertion of the mic to give sufficient grip. I have printed them in both PLA and PETG filament (with solid infill) so nothing fancy is required: the PETG filament gives a bit more flexibility and is what I have been using for them mainly. If you are determined you can break them, but, of course, that applies to many a commercial-produced back-to-back clip!

There are two bits of metal hardware that you will need for each clip, which comprise an M3 thin square nut (standard size 5.5mm x 1.8mm), and one of the same M3 socket head button flange screws that Radius use, in this case 12mm long. Of course, you can just use the existing screws that come with your RAD-1 and RAD-2 shock-mounts, so strictly the only extra part you need is the square nut. Stainless steel A2 is best. I got both the nuts and some of the extra screws from Westfield Fasteners (in the UK).

You can go to the file here in Onshape and export in STL, STEP, 3mf etc. file format as required. Note that the clip looks a little skewed or angled when printed: this is deliberate since loading it with two mics opens up the two clips elements a little and consequently, with this built-in angling of the lower circle, the MS clip sits properly square and central (i.e. with the mic centres exactly one above the other) when in use.

MS clip showing vertical alignment when loaded with a pair of mics: a bit of a fiddle to compensate for the skewing effect when the clips are expanded to take the mics, but worth get right.

And, yes, with the MS pair nicely in the Radius Windshield hoops, you can not only retrofit them to InVision shock-mounts or, say, a Rycote Modular windshield, but even, with a bit of ingenuity, get them into a Rycote Nano Shield: with the rather high-set mount for the lyres in the Nano Shield there is not a lot of height to play with (which makes back-to-back clips a very imperfect solution: the top mic ends up right by the basket), so a 3d-printed mounting bar (here’s a link to this too) and mounting the Radius hoops on the underside gives a good workable solution.

While I am at it, here’s another view of the MS clips in Radius hoops being used in a Nano Shield: a pretty dinky MS set up!

Yes you can fit three mics into a RAD-1 and RAD-2 shock-mount!

Triple mic clip for 19mm Ø mics

For something a little more esoteric, I have also created a triple-mic mount to fit the Radius RAD-1 and RAD-2 hoops. Such a triple configuration of mics is something I have used from time to time for MMS (i.e. mid-side but with two different mid mics with different polar patterns – say omni and supercardioid – facing forward so that the polar pattern of the mid mic can be chosen in post) or side-by-side Blumlein with, say, a single supercardioid for recording a singing guitarist, as I demonstrated recently here. Previously I have had to use two pairs of back-to-back clips to connect three mics, which is a fiddle. As I said, a bit esoteric, but that’s the fun with 3d printing: making the commercially unviable possible.

In terms of design, this drew on the mid-side clip, but the loading of the three mics had an impact on the form of the different near circular forms, so even more complex curves were necessary to ensure a snug fit for each mic. I also chose to beef up the thickness of the clip a little, to 3mm, due to fear of the additional forces involved getting three mics into a single clip; and then angled the top interface/mating part by 3 degrees to allow for the change in angle arising from the necessary expansion of the individual clips due to inserting all three mics. In all, nine iterations were required, and doubtless there is room for improvement still: things like best thickness vary a little with filament used. I used a slightly different approach to the fillets, but that is a subtle change. The solid modelling takes a few minutes only, but the printing at finest quality takes an age! The interface, or mating, with the Radius hoops is the same as for the mid-slide clip, so the same size nut and screw are needed. I suspect not many will want to print this model – it is largely presented as showing the potential for very specific mic clips (inc. DIY) offered by the interchangeable design of the Radius hoops – but if you do want to use it, then you can download it (again freely) here from Onshape and choose which file format suits you for export.

And here are the triple clips as 3d printed.

EDIT (6.1.2025) More triple mic clips: double mid side (DMS)

I’ve also spent some time playing around with mic clips for double mid side (DMS), and, spurred on by receiving a Mini-ALTO 115 from Radius Windshields for field testing, I revisited this. DMS always feels a bit clunky (it’s that rearward-facing mid mic out front that seems so odd) and, though I’m never overly concerned about it, shadowing does seem more obvious than in, say, side-by-side Blumlein of MS. But using MKH 8000 mics with MZL connectors at least goes some way to reducing the bulk of the mics. With the size of the Radius hoops there is no scope for three mics in a vertical line so, as with, say, the Rycote Cyclone DMS kits, I have gone for the two mid mics set side-by-side (although facing opposite directions, of course) with the fig 8 centrally above. The wider front part of the MKH 8030 means that this needs to be taken into account by the front clip that holds it too: the fig 8 provides the only common mic spanning between the two mic clips, and there isn’t much to grab onto at the front, so I decided – like many a DMS rig – to include a couple of metal rods (these are chopped down ones, 2mm in diameter, that were redundant from a Rycote MS stereo Cyclone kit 5 – where they are superfluous and, indeed, prevent better rigging). Anyway, here are a few images of the model (you can download the front and rear clips from Onshape) and the resultant rig.

Rear clip for DMS, showing holes for 2mm connecting rods.

The 3d-printed clips with connecting rods in place.

And the DMS rig set up in Radius hoops (the mount looks a little different since this includes the ‘smiley face’ adapter that allows the RAD-2 shock-mount to be used with the Mini-ALTO windshield).

EDIT (8.5.2025) A 19-20mm variant of the MS clip

I have been asked whether I could make a version of the MS clip that allows a combination of Schoeps (20mm diameter) and MKH 8000 (19mm) mics, so have modeled this and you can download from/view in Onshape here. There is a caveat: at the time of writing I have no Schoeps mics, so the fit of the 20mm hoop is my best estimate for the right amount of grip. And here’s an image of the 3d model.

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Audio Gear Audio Projects

MKH 8030 pair: a Blumlein variation for singer-guitarist Greg Brice

September 23, 2024

Blues singer and musician, Greg Brice, was up from the Cotswolds to Norfolk for a gig, and while he was here we headed over to the workshop of Luke Chapman (woodcarver and a blues musician too) to record and film a couple of songs. Greg is an up-and-coming musician, which is reflected in his three nominations in the 2023 UK Blues Awards: he was a finalist in the ‘Emerging Act of the Year’ category. The workshop, which was formerly a farm dairy, is decidedly not a music studio, but with a recent album out that wasn’t the aim. Rather we wanted to capture a couple of live acoustic recordings on location. As sharp-eyed readers of this blog may have noticed, the workshop is somewhere I have used before for recording, sometimes for mic tests and sometimes for more full-fledged recordings. In fact, Luke and I are thinking of getting many more musicians to record there in a kind of down-home NPR Tiny Desk Concert meets Gems on VHS series, but with extra sawdust on the side. So Greg was the first, and hopefully not the last, of the new ‘Milk, Wood and Dust’ sessions.

Close-up of the three-mic array, showing the angled capsules of the side-by-side MKH 8030 fig 8 mics.

The usual problem when recording a singing guitarist is to get good separation between the instrument and the vocals (to allow different tweaking of levels and other processing later), without resorting to recording them separately: overdubbing often results in a less than fluid performance. When I recorded singer-songwriter Lucy Grubb in the workshop last year, I went for a variation on double mid-side recording, with two mid mics facing forward: one upward to her mouth and one downward to her guitar, with the nulls of the mic polar patterns reducing spill effectively. It is a simple set up that also has the merit of being less visually intrusive than an LDC right in the singer’s face. There is a Sound on Sound article by Hugh Robjohns from a few years ago that discusses and illustrates the approach. It’s a bit of a clunky set up, however, and the stereo vocal seems a bit unnecessary (and potentially problematic as singers often move their heads about), so I have been thinking about another technique also making good use of the deep nulls of fig 8 mics, but aiming to get a stereo recording of the guitar and the voice in mono.

What I came up with as a solution was a Blumlein pair of fig 8 SDC mics (in this case the excellent new Sennheiser MKH 8030, which I have been testing in various blog posts: see here for part 1), combined with a super-cardioid for the vocals (I went with a Sennheiser MKH 8050). To keep it compact I placed the two fig 8s side-by-side instead of in the more usual end-to-end arrangement: now some theorists will break out in a cold sweat and say this isn’t Blumlein, but the reality is that, with capsules only at 23mm centres, the very slight non-coincidence has little impact (and, of course, is nothing compared to the spacing in near coincident pairs, such as the Gerzon array, ORTF and NOS). Equally, a bit of shadowing of the rear lobes is no big deal as they are only capturing a little uncorrelated reflected sound from distant walls. With the super-cardioid mic placed on top, the tight cluster (which I placed in a single shockmount: a Rycote InVision USM-L) was positioned around chest height and angled so this pointed upwards for vocals, with the Blumlein pair then angled down towards the guitar. This left the nulls of the fig 8s and the super-cardioid to do their work and minimize bleed from guitar to vocals and vice versa: and any bleed left was coincident and consequently sans phase issues. Now, it may well be that others have used this approach before, but I can’t find any reference to it: I wonder if this reflects that it is best suited to SDC mics and many will not have more than one SDC fig 8, if that.

I did a few tests beforehand and was happy with how the array sounded, so when Greg came over to the workshop I put it into action. Set up was easy, with the mics fairly close (the acoustic of the workshop is OK – and certainly without a ‘small room’ sound – but it isn’t the Wigmore Hall), but distant enough and off-axis so that no pop filter or foam was required for vocals, which would rather have worked against the minimalist approach. I was pleased with the results (and so was Greg), and see this as a discreet and quick to deploy array (I had the mics ready to roll in the shock-mount already), which will really suit more singer-songwriters down in the workshop or, indeed, similar recordings elsewhere on location. Have a listen and, if you think there is any merit and you have a pair of SDC fig 8s, perhaps give it a try.

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Audio Gear

Sennheiser MZF 8000 ii

August 24, 2024

My series of field tests of the new Sennheiser MKH 8030 fig 8 (which kicked off with initial tests, moved on to mid-side recording, encompassed field recording, included comparison with the MKH 30, and most recently included use in a native B-format array) have led to various questions being asked of me, both via this blog and on sound forums. An interesting one was whether the mic needed the modular filter that Sennheiser make for the MKH 8000 series: the MZF 8000 ii. This filter was announced at the same time as the MKH 8030, in September 2023, but, as I understand it, was available beforehand as a special order option instead of the original MZF 8000. Both filter modules are the same in terms of the switchable -10 dB pad and the fixed low-cut filter of –3 dB @ 16 Hz (18 dB/oct), but differ with regard to the switchable low-cut filter: on the newer filter the latter is –3 dB @ 70 Hz (18 dB/oct), compared to the original’s –3 dB @ 160 Hz (which was much less steep too: I can find no authoritative specs). This stems from understandable user feedback, since a lower and steeper HPF around the 70 Hz frequency of the new filter is of more use to broadcast and filmmaking sound for those mics in the MKH 8000 series that don’t have in-built bass roll-off (i.e. all except the MKH 8060 and MKH 8070 shotgun mics): more use, that is, for reducing low-frequency wind noise and handling noise.

While some might (and, indeed, do) lament the absence of a built-in pad and switchable low-cut filter in the MKH 8000 mics, as found in the earlier MKH mics, the modular nature of the MZF 8000 ii filter means it is more flexible and, also, the end result is quite different. Flexibility is seen in the fact that the MKH 8000 mics, sans filter, can be kept small and, moreover, when the filter is used, this can be placed either between the head and the XLR module (making for a 29mm longer mic) or, if using an MZL cable, well away from the mic head, and next to the (then remote) XLR module. As for sonic differences between the MZF 8000 ii and the in-built equivalents of the MKH 30, 40 and 50, arguably the fixed 16 Hz low-cut filter of the former simply compensates for the increased bottom end of the MKH 8000 series mics, but there remains quite a difference in the switchable low-cut filters: the MKH 30, 40 and 50 have much higher and gentler low-cut filters, designed to address proximity effect, rather than the lower and steeper filtering of the MZF 8000 ii filter that is geared to reducing wind and handling noise. And, to add complexity, the MKH 20 switchable filtering is only concerned with high frequencies, being to modify the mic between near and diffuse field applications (with, of course, the proximity effect not applying to an omni anyway). The earlier MZF 8000 filter, therefore, was more comparable to the switchable elements of the MKH 30, 40 and 50, while the newer MZF 8000 ii is more overtly geared to production sound.

A pair of MKH 8030 mics: one with the MZF 8000 ii filter and one without.

OK, so much for the theory: how does the MZF 8000 ii perform? With the focus of the MZF 8000 ii on production sound, I fitted the filter to one MKH 8030 and mounted a pair of the mics in Rycote Invision 7 shockmounts to a short stereo bar on the end of a carbon-fibre boom pole. First off I compared the impact of mild shake (from straining muscles) on the two mics, with no high-pass filter (HPF) on the recorder, and just the fixed 16 Hz low-cut filter on the one with the MZF 8000 ii module fitted.

MKH 8030 on boom pole, with no filtering to remove low-frequencies arising from handling noise (note the scales and that gain was cranked up for all these tests).

Recorded simultaneously with the above, but recorded with a second MKH 8030 with the in-built fixed low-cut filter of –3 dB @ 16 Hz (18 dB/oct) of the MZF 8000 ii.

As expected, the MZF 8000 ii filter removes a significant amount of the infrasound, whilst having little impact on other low-frequency performance.

Moving on now to compare the effects of using the high-pass filters built-in to most recorders and mixers versus, or in conjunction with, that of the MZF 8000 ii filter, first of all I repeated the boom pole test with one mic with the recorder’s 40 Hz HPF (40 Hz being the lowest setting on Sound Devices 788T) with the other mic using the MZF 8000 ii’s 16Hz filter and the 788T’s 40 Hz HPF:

MKH 8030 on boom pole, with 40 Hz HPF on Sound Devices 788T to remove low-frequencies arising from handling noise.

Recorded simultaneously with the above, but recorded with a second MKH 8030 with the 16 Hz low-cut filter of the MZF 8000 ii plus a 40 Hz HPF on the Sound Devices 788T.

Again, as expected, the 16 Hz low-cut filter of the MZF 8000 ii adds significantly to reduction in handling noise from the boom pole by use of the recorder’s 40 Hz HPF.

For most such boom pole (or, indeed, pistol grip) mounting of a mic of course one would anticipate using a higher frequency HPF such as the switchable one built into the MZF 8000 ii, so that formed the next test: i.e. comparing the Sennheiser module with the 70 Hz HPF of the Sound Devices 788T.

MKH 8030 on boom pole, with 70 Hz HPF on Sound Devices 788T to remove low-frequencies arising from handling noise.

Recorded simultaneously with the above, but recorded with a second MKH 8030 with the 70 Hz HPF of the MZF 8000 ii.

Going by the frequency of the two HPFs some might expect that the results would be same, but the MZF 8000 ii’s 70 Hz filter has a much steeper slope (18 dB/oct) compared to that of the 788T (selectable at 6 dB/oct or 12 dB/oct: I used the latter), and this difference is clear. By contrast, the more recent Sound Devices 8-series and Mix-Pre recorders have 18 dB/oct HPFs, so the final test with the boom pole compared the MZF 8000 ii’s 70 Hz HPF to that of a MixPre-3: the latter only goes up in 20 Hz steps, so was set at 80 Hz.

MKH 8030 on boom pole, with 80 Hz HPF on Sound Devices MixPre-3 to remove low-frequencies arising from handling noise.

Given the steepness of the slope and the slightly higher frequency, the MixPre-3 shows more attenuation of boom pole handling noise.

So far, this is all very much as expected from the specifications: but where does this leave us? What are the benefits of the MZF 8000 ii in terms of its HPF if the recorder/mixer has one too? And, likewise, what is the benefit of the -10dB pad if, as is sometimes the case (e.g. the 788T), the recorder can supply 48v phantom power in line-input mode to cope with mics recording very high SPLs and consequently producing high outputs? Well, this is complex, and will reflect the type of material being recorded, the modus operandi of the sound recordist, and the capability of the mixer/recorder. In some cases, stacking HPFs (i.e. in both the mic and the recorder/mixer) may be useful to give a steeper slope: this is especially relevant if the recorder itself doesn’t offer anything as steep as 18 dB/oct. In many uses the fixed 16 Hz HPF of the MZF 8000 ii will be useful to remove unwanted infrasound, and many mixer/recorders do not have HPF options that go this low. In some cases the MZF 8000 ii will stop the mixer/recorder preamps being overwhelmed by, or giving too much headroom to, unwanted low frequencies: this is especially relevant with those recorders (such as the Zoom F8n) where the HPF comes after the trim/gain and ADC. Of course, any such uses need to be balanced against the additional weight of the module (relevant at the end of a long boom pole) and the lack of accessibility of switches if the mic is in a windshield. And it also needs to be considered against other options that are outside the mic or the recorder/mixer, such as the switchable 80 Hz HPF built into the XLR mount of the Rycote Nano Shield (and therefore accessible outside a windshield).

So, in short, it will come down to personal choices: the module is primarily of use to those for whom mic handling noise, wind noise, unwanted low-frequency ambient noise, and, for the pad, extreme SPLs are issues, which will mainly comprise production/ENG sound, sound effects recording, and, to a lesser extent, field recording. As for using the MZF 8000 ii with the MKH 8030? Well, although this has a decent bottom end for a fig 8 mic, it naturally has less in the way of a low-frequency response than its omni, wide cardioid, cardioid and supercardioid siblings and is also less likely to be swung around vigorously on a boom than, say, the supercardioid MKH 8050. In short, to date I haven’t found a need to use the MZF 8000 ii with the fig 8 MKH 8030: others may draw different conclusions. However, I’ve found it useful to have the MZF 8000 ii in the kit, and so far have used it most with just the 16 Hz low-cut filter with the MKH 8020, where the very bottom of the extended low end of this omni mic isn’t always wanted: and its good to be able to have the 70 Hz (18 dB/oct) filter and the -10dB pad there for whenever the need arises. Turning this around the other way, and again unlike some others, I’m glad that with the MKH 8000 series mics Sennheiser took a modular view to the HPF and pad capabilities since, for the bulk of my recording activities (and I suspect those of so many others), they aren’t needed and the consequently more compact form is useful: evidently the MZL cables take that compactness further, but that’s another matter!

And just for a size comparison here is my MKH 50 alongside MKH 8050 with the MZF 8000 ii. The latter adds to the size of the MKH 8050, increasing its length to 103mm and its weight to 81g: these are significant increases of 39% and 47% respectively from the MKH 8050 just with its MZX 8000 XLR module, but still well short of the MKH 50’s 153mm length, 102g weight and, of course, greater diameter (25mm vs 19mm).

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