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If only boom poles could grow legs…

February 17, 2023
Options for mic supports outside: camera tripods, lighting stands and a boom pole.

Field recording can mean mics on a pistol grip for a quick grab of a sound, on a boom pole for something equally quick but harder to reach, or clipped to a bag or hat for some stealthy ambience recording. But much recording outside – and that includes music – requires something more stable and static in the way of support so the mics can stay steady and the recordist can step right way to monitor from afar – not least to avoid capture of rustling, breathing and stomach gurgles from the recordist. Strapping mics to either side of a tree (‘tree ears’) can work, but, of course, there may not be a suitable tree to hand in the right place, so, mostly, it’s a case of taking a stand with you. The trouble with that, of course, is that there are no commercially available stands that have been purpose-built for field recording: so it’s a case of making do with what’s out there. In this post, I’m going to look at the conventional options I have been using in different situations, plus one additional option that I have put together recently and which others may want to try.

Mic stands

Conventional mic stands have little value outside unless in the tamest of environments (think streets, pavements, patios and lawns), being heavy and, with their circular or short fixed tripod bases, have no adaptability to uneven terrain. Not to be sniffed at if you have nothing else – and a short mic stand (the sort you might use for miking a kick drum or a guitar amp) could work fine for recording out in nature with mics near the ground – but not something I’ve found an attractive option.

Lighting stands

Lighting stands are great alternatives to mic stands indoors, not least for getting mics up high for, say, recording an organ, choir or orchestra: obviously they aren’t so good when you want a small footprint, or a short boom arm. They are also useful outdoors, and with a wide range of sizes, can cover a range of uses. When hiking/travelling light I often take a Manfrotto 5002 Nano Plus stand, which folds down to 52cm (it can fit in a rucksack with a blimp), yet extends to 1.97m. It has one slightly extendable foot so has a bit of adaptability to uneven terrain, though nothing very dramatic. It’s the beefiest of the Manfrotto Nano stands (taking a 4kg payload), but I can’t pretend it is rock solid: out in the wind anything above its shortest length is a bit hairy. I tried out the slightly lighter Manfrotto Nano Pole stand in the local camera shop, since it is lauded by some field recordists and looked good on-line, but it was not for me: it was so much flimsier than the 5002 Nano Plus stand and the removable centre column can hardly pass muster as a boom pole. At the taller end of the spectrum, I have a Manfrotto 1004BAC: this is my go to stand for recording acoustic music indoors when not close miking, and I’ve used it outdoors too many a time. It is in a different league than the little Nano Plus stand, rising to 3.66m and carrying up to 9kg (but still only weighing 3kg): it can happily support my chunky stereo bar and, even, my massive windshield for two LDC mics. Outside, though, it has the downside of lighting stands: the legs are designed for a flat surface and the tripod legs only rise a short way up the central pole or column, so it is prone to wobbliness and vibrations especially when extended.

Camera tripods

Many field recordists use camera tripods, and with good reason: the better engineering and, above all, the stability of legs rising much higher take away most of the wobbles and vibrations; many models can collapse far smaller than even the diminutive Nano lighting stands; many models can get mics close to the ground, unlike lighting stands; the legs are adjustable for length and angle, so the tripods can be used pretty much anywhere, even in water; and, of course, they can be used for their primary purpose too (less to carry, say, when hiking to the recording location). Obviously, adaptation is needed to connect mic clips/suspensions, or a stereo bar to the camera head (or remove that), but this is basic stuff: and use of quick-release plates means that you can swap from an audio to camera set up in seconds. There are a few downsides of varying significance: above all, camera tripods lack height, naturally enough being limited to average eye level or a little above; at full height the footprint of the tripod can be a bit large (not really an issue if, say, recording natural ambiences); with no full-height pole/column element, cable routing can be a bit fiddlier; and some tripods can take longer to set up than, say, a Nano Plus stand.

Options for mic support outside, left to right: Gitzo GB3560 carbon-fibre boom pole, Manfrotto 1004 BAC lighting stand, Manfrotto 5002 Nano Plus stand, Manfrotto 055 Pro camera tripod, and, then, the same at two different heights with a boom pole clamped to it (and, no, I don’t have three identical boom poles and three identical 055 tripods…!).

Boom pole with camera tripod

Advocates of the little Manfrotto Nano Pole stand often cite the removable centre column for use as a boom pole as a key attraction, although, as I said above, it’s a very poor substitute for a real boom pole and the stand itself is flimsy too. But the idea has merit: it is so handy having a boom pole in the field (great not just for any dialogue, but also for those hard to reach sounds – once you use a boom pole you will come to appreciate how many such sounds can be recorded, or better recorded, with the reach and the distance from you it provides – or when moving around, sans stand, catching quick close-up sounds) and it’s annoying carrying bits of kit that have very similar – and duplicated – elements to them. So it’s a pity that no manufacturer has scaled up the Nano Pole idea to produce a more stable stand, perhaps with leg geometry more like a camera tripod, with a decent-sized carbon-fibre boom pole at its core (or, better, the ability to incorporate a range of different boom poles from different manufacturers). I’ve looked for tripod legs that could be used to cobble together something with my boom pole, but with no joy. Then I had the idea (doubtless not the first or the last to do so) of mounting the boom pole to a camera tripod head with the bottom of the pole resting on the ground (crucial for giving stability), essentially making a four-legged stand. Looking around, the nearest thing I found to this out there is a tripod pole bracket made by Hague Camera Supports for attaching an aerial camera mast to a camera or video tripod: rather too massive and laborious for the sort of slick set up I had in mind, but it was reassuring to find someone thinking on similar lines. So to my rather smaller and quicker to use solution: a quick-release 30mm rod clamp (made by Camvate) fixed by two 1/4″ screws (i.e. ensuring no rotation) to an Arca-style quick-release plate. Both the plate and the clamp can be fixed to the tripod and the boom pole in seconds, and the pole can be set vertically or at an angle, with its bottom end firmly planted on the ground. It can be used with any of my Arca-fitted tripods – from the reasonably substantially Manfrotto 055 pro with large ball head, down to my little Benro travel tripod. And the advantage? Well I can use the tripod alone for mic support when convenient; I can use the boom pole alone when useful; and I can combine the two in seconds to get a far more stable tall stand than my current most substantial light stand (indeed, at 4m long, taller than my Manfrotto 1004BAC) with completely adjustable legs. It was a very blowy day today, so I was able to confirm stability in fairly extreme conditions (using Rycote Nano Shields with fur as windshields): at the 1.97m height of the Manfrotto 5002 Nano Plus stand it was completely stable, while the Manfrotto 1004BAC had a significant wobble, and the Nano Plus stand was worse still (both given extra stability by a heavy camera bag hung off them); and at the full 3.66m height of the 1004BAC the boom pole set up did wobble a bit, but less so than the lighting stand and, crucially, vibrations/wobbles calmed down much more quickly. Obviously, as would be expected, the advantage afforded by the taller legs of a camera tripod vs those of a lighting stand diminishes as the boom pole gets towards its maximum of 4m and also as the boom pole sections reduce, but it was interesting to see that the lighting stand didn’t out perform it at such height. For £30 for the rod clamp (and others may find/need different and better solutions for their boom pole), I have another flexible set-up to add to the choices when I take my sound gear out into the wilds, especially when I know the terrain won’t suit a lighting stand.

Top left, Camvate 30mm rod clamp; bottom left, the rod clamp (given a little internal lining to be gentler on my carbon-fibre boom pole) screwed to an Arca-style quick-release plate; and right, the boom pole then attached via these to the ball head of a camera tripod.
And outside in high wind with the boom pole fully extended (about 4m). If setting up for longer in such wind I’d have hung my sound bag off the tripod for a bit more low-down weight.

Audio Gear DIY Projects

Mid-side with AKG CK94

May 25, 2021
AKG CK94 (top) and CK93 (bottom) in Rode Mk1 blimp suspension

I’ve had one of the AKG Blueline mics for years. This has the CK93 capsule, which is an excellent mid-price hypercardioid SDC mic that has proved great for booming indoor (and, on occasion, outdoor) dialogue. I have also used it for music recording where I needed a narrower polar pattern than cardioid. It is leagues above my Oktava MK012 hypercardioid – so beloved by indie filmmakers – in terms of build quality, handling noise, and features (having low-cut and attenuation switches).

From time to time I’ve wondered about the other interchangeable capsules in the Blueline range and, above all, about the CK94 – the figure of eight capsule. Of course LDC multi-pattern mics include a fig 8 polar pattern and, paired with another mic, this allows mid-side recording, which I have done many a time. And, as I have posted, with a massive DIY blimp I have even got such an LDC pair outside for field recording. That said, it would be useful and, for most uses, more practical to have a compact SDC mid-side pair. The standard for field-recording pros is the Sennheiser MKH30, which, while excellent and with the advantage of humidity-beating RF technology, has the distinct disadvantage of cost: it has a street price of around £1500, and even used ones seem rare below £1000. Add another Sennheiser MKH mic (say an MKH40) and wind protection to fit and you will need to spend £3000 or more. Unlike other polar patterns, SDC fig 8s are rare, and there are few more affordable ones: ignoring the clunky pseudo fig 8s made by Oktava and Kortwich (made using two cardioids mounted back-to-back, giving a T-shaped mic), the only affordable true single -diaphragm fig 8 other than the AKG CK94 is the Ambient ATE208 Emesser. The latter, however, has a lot of bass roll-off due to it being tailored to match the off-axis response of a shotgun mic (its intended partner). Recently, boutique Taiwanese mic-maker B9Audio has produced the CM180, but it is only available direct from the maker: so this means significant shipping and duty costs need to be added to the US$749 price. Reviews are also thin on the ground to say the least.

So, with all this in mind, the AKG CK94 remains the most viable affordable SDC fig 8 for general usage (i.e. music as well as film sound). Although now out of production (AKG/Harman/Samsung appear to be phasing out the whole Blueline family and the CK94 was the first to be discontinued), at the time of writing it is just possible to find one or two new examples for sale: with the SE 300B amplifier/mic body, street price is around £600. But I’ve been keeping my eye on the used market, and was please to spot one on the Saturn Sound website (where there is a list for a grand closing down sale of mics – with some very rare examples), and – together with the SE300B amplifier/mic body – the other day I became the owner of a very good condition example: indeed, during a pre-sales check, Ashley Styles of Saturn Sound thought the capsule a bit noisy and replaced it with one he still had. All this, plus delivery in person (he has retired not so far away), for a remarkably affordable £200.

I had no concerns about the CK94 for music or louder effects recording, but, with 22dBA self-noise (a long way from the MKH30’s 13dBA) my hopes were low for recording quieter ambiences. So I was surprised how good it sounded during an initial test recording the ambient noise in the garden (in a village in rural Norfolk). You can have listen here:

I was expecting something much noisier.

In terms of rigging it up for field recording, I purchased a couple of the older style (i.e. lower profile) back-to-back clips made by Rycote (ref. no. 048460), which, unlike the new fit-any-mic clips Rycote make for MS pairs, neatly fit into a Rode Mk1 blimp and have lugs to attach to the suspension bands: the mics sit centrally and with a healthy blimp diameter of 100mm there is still plenty of air space around both mics. The CK94 has to project further forward given the location of its capsule (the centres of the two capsules should align, of course). I’ve added a DIY conn box equivalent (a clamp for the two thin cables – Sommer Cicada – that go from the mics to the DIY boompole-top XLR holder) to avoid the two heavier cables entering the blimp, so I’m there with a very nice sounding SDC mid-side rig for a very modest outlay. And, of course, I can use the AKG CK94 with mid-mics other than the hypercardioid CK93: for example, my Rode NT55 mics give me cardioid and omni mid-mic options. I’ll post other recordings – including music – with the CK94-based mid-side rig in due course.

With blimp on, and showing the double XLR holder at the top of the boompole
And a close-up of the DIY double XLR holder at the top of the boompole
Camera Gear DIY Projects

This camera is not for turning…

March 25, 2021
Compact follow-focus rig with an anti-twist Arca-type plate.

The best ideas for inventions are those that turn out to have already been thought of and produced. OK, that means you can’t make your fortune, but odds are you wouldn’t make the leap from an idea hatched in the shower to a production line anyway: and, anyway, you can go out and buy the thing with none of the hassle of being the next James Dyson. This happened to me with my genius solution to feeling all tangled up and constrained by sleeping bags when camping: just imagine if the sleeping bag had separate legs and arms? Well, as you probably know but I didn’t, you can buy these already…

To the case in hand, I’ve long been frustrated how stills cameras rotate all too easily on tripods, fixed (in the loosest sense of the word) by a single 1/4″ screw and lacking the additional pin hole found on camcorders. With stills cameras then moving into video and, for cinematic focusing, then needing follow focuses, the need for anti-rotation got all the more compelling. While camera companies vie about 4k and 8k, or 10-bit and raw on mirrorless cameras, nobody seems remotely bothered to drill a hole in the base to allow a second pin to stop rotation. An L-bracket or a cage can sometimes solve the problem, but, unless you need one, they are clunky additions, making access to controls and connections much harder and losing the carefully designed ergonomics of the camera. Also, many L-brackets and cages are just not rigid enough or not fixed to the camera well enough. With my compact – and cageless – follow-focus rig for my Lumix G9 I’ve found the old problem rearing its head, with the camera sometimes gradually rotating away from the follow focus to the point that, eventually, the gear disengages. So my genius ‘invention’? Well, simply a small Arca-style plate with a ridge at the front, forming a snug fit against the front of the camera: with the G9’s flip screen there is no value in a ridge or lip at the rear. Visions of finding someone who could mill one for me proved unnecessary since, as you will have guessed, the idea has already been thought of. Oddly, though, I haven’t simply missed something common, as such plates are incredibly obscure. Arca themselves sell an anti-twist plate (the blandly named ‘Kameraplatte 40mm’) as do Really Right Stuff (the equally unrevealingly named ‘B9 Multi-use bidirectional plate’), but both are extremely pricey for a small bit of metal with a lip (€63 and $49 respectively), need an allen key to tighten, and are hard to find in the UK. And then I came across the plates made by the Colorado Tripod Company in the USA: a perfectly sized 40mm plate (they do 60mm and 85mm-long versions too) with a bolted-on lip, and, unbelievably (since their well-made kit isn’t generally cheap), available for $10 (in my case £9 on Amazon UK). It turned up today, and is a supremely well-engineered plate, and even includes miniature bubble levels: you can tighten it with fingers or a coin. I might not have made my fortune with a new invention, but it hasn’t cost me a fortune either: I just wish I’d realized, and hunted for, the solution to camera twisting before.

UPDATE 18.6.2021. Well, sadly my optimism about the off-the-peg anti-twist plate wasn’t entirely merited: after a month or so in use I found the plate still undoing from time to time: not as badly as before, but enough to be frustrating. The reason for this is evidently the slot (instead of a hole) for the screw, also common to the more expensive offerings from Arca and Really Right Stuff, which, while designed to allow fitting of the plate to different cameras, allows the screw to loosen when used with a follow-focus. Doubtless, the designers didn’t have that in mind. What is needed, evidently, is a plate with a hole rather than a slot for the screw, which, of course, means a plate designed perfectly for the camera body. So, after all, it was necessary to DIY something: I simply added an aluminium bar at exactly the right point (with some very careful sub-millimetre measurements) to an existing Arca plate and – voilà – at last I have got there: in use it has proved reliably rigid.

Colorado Tripod Company anti-twist Arca-type quick-release plate with lip at the front or rear. The detachable front/rear part with the lip (and bubble levels) is bolted on from below and further aligned by two pins that slide into the main part of the plate. Sadly, like any such lipped plate with slot for the screw (which allows it to fit many different cameras), it will still loosen under the duress of a follow-focus.
My modified Arca-style plate with the screw through a hole and an aluminium bar bolted on so as to perfectly abut the front of a Lumix G9. Not pretty, perhaps, but at last rock solid with a follow-focus.
And here’s the DIY-modified plate on the camera. I’ll probably paint the aluminium addition black in due course, but, meanwhile, it is clearer for these photos.
Audio Gear DIY Projects

Primo capsules – for lav mics and DIY

February 7, 2021
A pair of the tiny Primo EM272 omni capsules: add two wires and a 3.5mm plug and you are ready to record!

Primo microphone capsules are much-loved by the DIY crowd, especially the omni EM172 (now replaced by the EM272) capsule: it is a 10mm capsule with 14dBA self-noise. As such it offers similar scope to a lavalier (lav) mic for times when you want something much smaller than a small diaphragm condenser (SDC) mic, but has much lower self-noise: lav mics typically have around 22-5dBA self-noise, which can be pretty noticeable for many recording uses, such as ambience and nature recording. The sound quality is on a par with capsules used in mid-range handheld recorders, but, of course, once you have external mics you can be much more flexible. For example the omni mics on the much-loved Sony PCM10 are too close together for stereo, so plugging in a pair of EM272 mics allows for a proper spaced pair: you can clip those to your hat, the sides of your specs or, to look slightly less silly and to avoid your head movement giving odd shifts in the stereo image, to the sides of a bag or rucksack.

And the best thing about the Primo capsules is that they are cheap. Currently in the UK an individual bare capsule is £12.78 from FEL Communications Ltd (Micboosters): FEL/Micboosters also offers various versions (e.g. pre-soldered), other Primo capsules (including cardioid and figure 8: see below), matched pairs and, for those not into DIY, capsules already made up into finished mics – their Clippy and Pluggy models. There are a couple of other manufacturers who use Primo capsules in affordable mics, the most well-known of which is LOM in Slovakia, but I think Micboosters is the only one that also sells the bare capsules: and it is one of those great small British companies, run by the very helpful Nick Roast, who has worked as a BBC sound engineer for over 30 years.

A pair of Clippy mics

I have a pair of the Clippy mics (together with Rycote furry covers that are made specifically for them), which are useful for discreet or minimalistic stereo recordings and as lower noise lav mics for dialogue. And I have used bare EM172 capsules for what Curt Olson – who inspired my experiments – calls a ‘head-spaced parallel barrier array’, albeit in my case small enough to fit inside a Rode Mk1 blimp and with some of the mic placement attributes of SASS arrays: the circular baffles are c.90mm diameter and the mics are 160mm apart. Surprisingly effective. I’ve also used an EM172 to make a boundary mic, with the capsule set off-centre in a disk of perspex (150mm diameter and 5mm thick). Perhaps next I should buy some silicon ears (I see Micboosters sell them too) and make a binaural head with a pair of EM272s, as others have done.

Primo also make a single diaphragm figure 8 capsule (the EM283), again 10mm diameter, but this is not normally available via retailers. I noticed that Micboosters had started selling them and, as I had never heard of the capsule nor could find anything about it via the internet, I bought one for the princely sum of £19.68 for fun/curiosity. The specs are not as attractive as the EM172/EM272 and the 22dBA self-noise might be rather too high for many, but it is fine when used as part of a mid-side pair for louder sources such as music or some street ambiences. I found that the EM283 capsule needs better RFI screening than the EM172 and EM272, but that’s nothing unusual. I just bunged it in an old sawn-off shotgun mic tube for testing and, though this makes the mic unnecessarily large, it is fine – all hum eliminated. At some point I’ll get around to making a smaller housing with the fine mesh screening I have bought for the job. Not entirely sure if I’ll make much use of this capsule, unlike the EM172 and EM272 ones, but it has proved useful in an odd way: I had been thinking of acquiring an AKG CK94 figure 8 mic to provide the side mic for a mid-side pair with my CK93 hypercardioid, but was worried about self-noise (the CK94 is also 22dBA) and this convinced me that for my intended use I really do need something a lot quieter (so will need to save for an MKH30). UPDATE 26.5.2021: despite my conclusions about the EM283, I did buy a used AKG CK94 after all (a bargain came along) and its theoretically identical self-noise of 22dBA is not at all problematic. Lesson learned? That not all self-noise specs are equal! I’ve written a blog post about the new mic here.

So the final word: I’d really recommend playing around with bare Primo capsules as a cheap way to learn about arrays, and, even if DIY isn’t your thing, I’d recommend a pair of ready-made Clippy mics with these capsules as a great and very affordable alternative to a pair of lav mics for those occasions when SDC mics (and P48 power) aren’t feasible.

Primo EM272 capsules as delivered: matched pair with measured sensitivity a bit better than the published specs.
A head-spaced parallel barrier array – with the influence of SASS arrays – built to fit inside a Rode Blimp.
A boundary mic with an EM172 capsule: so simple and cheap, but better performing than so many commercial offerings.
A size comparison of a Clippy mic and a miniature lav (in this case my Rode lav). The Clippy’s EM172 capsule makes it rather chunkier, but for many uses this isn’t a problem, and it is still small enough to hide under much clothing.
Experimenting with a Primo EM283 fig 8 capsule: mounting it inside part of an old shotgun mic body.
And using the Primo EM283 fig 8 mic as the side mic in a mid-side mic pair with a Rode NT55.
DIY Projects

Speakers – exponential tapered horns

January 30, 2021

Though not strictly part of filmmaking or sound recording, ultimately playback is on hi-fi speakers (well for those not limiting themselves to earbuds!) and having something decent on which to check mixes other than nearfield studio monitors is critical. To me, speakers means DIY and I have been playing around with them since childhood: an early speaker project around undergrad days was a long-throw horn using WEM drivers, and then a few years later, when a thick cold meant I wasn’t feeling much like working on the thesis, I made my first exponential tapered horn speakers, loosely inspired by Laurence Dickie’s famous Nautilus B&W speakers. The rationale of the Nautilus design (and subsequent speakers using this approach) is to use tapered tubes to absorb the rearward sound produced by the drivers, to stop it being reflected back (as in a conventional speaker cabinet) through the driver again, adding unwanted resonances and colour.

The 1990s old snake speakers, with B&W drivers and that chipboard aesthetic

These first tapered horn speakers weren’t snail shaped like the Nautilus (too complex and derivative) but, rather, vaguely snake shaped, built simply out of chipboard, and had more of the WEM PA speakers: they weren’t very hi-fi at all. But modifications quickly followed. I was given some spare B&W drivers (I think for their 802s, but they are marked ‘prototype’ on the back), so modified the snakes to take them, and then some backroom boffins at B&W kindly stuck them in their anechoic chamber, stuffed them properly (I was too tentative with my wadding), added plasticine under the tweeters to take out a nasty reflection, and designed and built crossovers to suit: this might seem unusual, but I was brought up in the small Sussex market town of Steyning, where B&W’s R&D centre was located, so enthusiastic and generous research staff were thick on the ground.

I’d always meant to house the speakers in something rather nicer than chipboard, but the decades slipped by (actually over 25 years) and it took the Covid-19 lockdown for me to get round to it. Somehow the project rather developed: instead of re-housing the early 1990s B&W drivers (or, actually, similar: I had a spare set), I was offered some rather more modern and better (indeed, world-class) drivers (including metal-coned pistonic bass/mid drivers) actually designed for this type of speaker, and, again, some technical support (e.g. on crossover design and build). I’ll draw a discreet veil over which (different) manufacturer gifted them this time (those interested can probably guess), as they don’t supply for DIY use: again, these were some spares knocking around – acoustically fine, but not quite pristine looking.

Half-model for the new design

For the new speakers I decided to go for laminated plywood construction. I like the aesthetic of varnished laminated plywood sculptures and it seemed an achievable way of building a complex curvaceous shape: there would be no flat sides this time round. Also, with laminated construction I could create fairly thick and inert walls. The overall form is similar, nonetheless: a rearing snake (or a large number 2 if you want to be more prosaic) and a two-way design with passive crossovers. And the underlying principle was the same. That is, the form was defined entirely by eye and a gut feeling that the exact taper of the tube isn’t critical, so there is no scientific analysis behind it! Work began with drawing in AutoCAD and was followed by the production of a 0.3 scale half-model – shades of boat building. After sanding this so it looked right the laminated sections were each scanned on a flat-bed scanner, and then inserted into the CAD drawing to allow tweaking of the shape of the templates.

Then construction for real started, with endless hours of cutting plywood just with a circular saw and, mainly, a jigsaw: with 30 pieces of plywood per speaker I was soon cursing the frugal approach that precluded handing it all over to a CNC-equipped workshop (partly due to lockdown-derived impoverishment and partly due to the fact that I wanted to build them myself). Then gluing the plywood sections together to make half-speakers: it sounds easy, but the awkward shape and slippery glue were a difficult combination, resolved by adding a few laminations at a time and holding things in place with piles of books. Fiddlier still was making the front plywood baffles for mounting the drivers: the drivers sit in rubber O-rings with fixings via threaded bolts out of the back of the speakers, so millimetre precision was needed (achieved by spinning my router round a nail). Then back to hard graft: heavy sanding – mainly with a belt sander – to get into something near the final shape. I must have clocked up more hours with a mask on in my own garden than anyone else in lockdown. With initial sanding done it was on to stuffing the lower half of the tapered tube with woollen jumpers (almost solid at the bottom), add cables, and then, without stray bits of wool mucking things up, glue the two halves together: more wool and then – for the top part – speaker wadding was added through the bass driver hole.

Setting out paper templates, and working how to fit to the 8ft x 4ft plywood sheets
Plywood laminations cut for one half-speaker
The not-so-sophisticated gluing process: lashings of Titebond and precariously-balanced books.
The first half-speaker nearly finished, with drivers loaded. The tweeter has its own (plastic) exponential tube fitted, and both drivers are held in place by bolts through the back of the cabinet – requiring careful alignment and rubber fittings to avoid resonance issues. The interior was intentionally left with a stepped effect since sanding (which would have been difficult) would not have improved the performance.

With one speaker roughly made, it was time for loading the drivers for testing. With no access to a handy anechoic chamber this time, the garden on a windless day was the next best thing – getting away from any nasty indoor reflections. The neighbours must have thought it odd as I fed sine-wave sweeps through the speakers: aliens in the village? Measurement (bass driver and tweeter separately) was via a Dayton Audio EMM-6 measurement mic, using its individual calibration data and REW software (useful not just for measuring room EQ). The results were looking hopeful, so data was sent to the crossover designer (a renowned loudspeaker designer, so in safe hands), then the crossovers were assembled for me (using hand-wound inductors, made on a slowly spinning lathe), and the tests run again, this time with both drivers in unison: superb results, with impressive waterfall plots revealing negligible resonances and reverberation. During the to-ing and fro-ing of crossover design and build, I ground on with construction of speaker no. 2, and then both speakers were given the finer finishing sanding, crossovers were fixed, and then the speakers were treated to several coats of high-gloss yacht varnish.

Gluing the two half-speakers together: not the easiest shape…
Measuring a speaker in the garden: the poor man’s anechoic chamber.
Almost there: soldering connectors to one of the varnished speakers.

And the sound? After teething troubles with one bass driver (an elusive intermittent distortion caused by a loose connector in the driver – as I said, these were spares, and had been knocking around on a shelf for a few years) were sorted, absolutely superb! REW results indoors were exactly as anticipated and aimed for. But, more to the point, listening reveals the sound to be uncoloured, responsive, clear, with a good stereo image, and easily sufficient bass (something I was wondering about) for the size of room. At some points the complexity of utilizing the new drivers seemed daunting (compared to the old B&W ones), but, in the end, it was worth it: not only was there an aesthetic upgrade (the original plan), but an equal acoustic one. For the cost of several sheets of ply, a lot of glue and jigsaw blades, some crossover components, a tin of varnish and countless hours (which were going free during lockdown anyway), I’ve ended up with some unique-looking speakers that to better performance-wise would cost upwards of £20k. And such a satisfying feeling. Given that the mark 1 snakes served over 25 years, these ones will see me out.

Ah, I forgot to mention, though, that there is one drawback: this time round you can’t balance a mug of tea on the top of the speakers…