Issue 91
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Home is Where the Studio is: Part 4

It’s been a long time between drinks but construction at ‘The Mill’ continues in earnest.


10 April 2009

Text: Andy Stewart

“We’re getting there…” If someone had tossed me a dollar each time I’d uttered this phrase over the last 12 months I’d be a wealthy man. Incredibly, it’s been almost a year since I last updated AT readers about progress at ‘The Mill’. To the many readers who have emailed me to find out what’s been happening, thanks for your concern but, no, the place hasn’t been blown over in a hurricane or swamped by rising sea levels… it’s just been slow going.

For anyone new to AT, ‘The Mill’ is the name of the home studio I’ve been constructing (with significant help from AT contributor Cal Orr) inside a shed beside my house for as long as I can remember. I’ve been writing about it infrequently in AT in the hope that others might benefit from my experiences – good, bad or indifferent – and from what I’ve heard, so far it’s been worth it.

The Mill is not a ‘home’ studio in the strictest sense of the word. I suppose if I were to be a literalist about it, it’s more accurately a ‘tractor shed studio’ – given its agricultural beginnings. I’ve been building it on and off for the best part of two years and although the end is now in sight, we’re not there yet.

I’ve learnt a hell of a lot along the way thus far: everything from how to plaster four-metre high gabled roofs without the aid of a sheet lifter, to building acoustic treatments out of straw bales, to restoring vintage Neve consoles and working inside a half built facility. This issue I’d like to briefly talk about a few of the mistakes and triumphs thus far.


The ‘tractor shed studio conversion’ has been a long and eventful undertaking, both physically and mentally, and in the last 12 months huge strides have been taken towards its completion. Admittedly, there have been several periods (sometimes weeks at a stretch) where nothing much has been done physically to the building itself. At other times progress has gone ahead in leaps and bounds.

So it seems appropriate to kick this issue off with a discussion about budgeting time rather than acoustic treatments or room isolation. We’ll touch on those other subjects in a minute, but right now let’s hop to it – time’s a wastin’.

Unlike the click tracks we often use as a foundation for song construction, building a home studio doesn’t seem to adhere to any strict tempo. I s’pose if I were to extend the metaphor further, home studios tend to adopt a lazy backbeat and constantly complain between takes that ‘the tempo’s a little fast’.

If I were to see the relatively slow rate of progress at The Mill in recent months as a shortcoming in some way (which it isn’t necessarily) the problem can essentially be attributed to a lack of planning. The fact is, there was never any real plan, and in a sense there still isn’t. Sure, we’ve had drawings and dimensions written down, but never any methodical plan to get us from A to Z. This has had the unfortunate side effect of making it difficult for others to give us a hand from time to time. Without a specific task for them to tackle, they’ve been relatively powerless to help, even when they’ve wanted to.

The timber frame goes down first.

Bales are pinned to timber framing with wire.

Internal timber rods add extra strength.

The final structure is impossible to budge.


The top priority is still to get the building sounding right, and that unfortunately takes time. This isn’t because countless changes are taking place, it’s simply because, for me at least, knowing what’s right and wrong with an acoustic space is best revealed over time. Sure, there are mathematical formulae that help define the ideal acoustic space, complete with golden ratios, evenly spaced modes and appropriately placed diffusion, but frankly, since most of the advanced acoustic theory seems conflicting and/or confusing, the best way I know of sorting things out is with my ears. It’s cheaper too. Although many of the principles of acoustic theory have been considered ad nauseum during this project, other factors – like ergonomics and aesthetics – have had their say too.

Consequently, assessing how far we are from the finish line is still difficult. This has occasionally led to feelings of frustration and disappointment, even though the studio’s completion has never been bound to any realistic (or even unrealistic) time frame. Being a home studio, I’m not even particularly convinced it will ever be ‘finished’ – in the strict sense of the word at least. I’ll always be changing or adding something, whether it be new (or old) audio gear, acoustic treatments or studio monitors. In many ways, The Mill is now a living organism with a life force of its own, and working on the building itself is inseparable from the albums it produces. Between Cal Orr and myself, I think we’ve mixed about seven full albums here already, so the line between audio work and physical labour is already blurred.


If this whole escapade has taught me anything it’s that building a ‘home studio’ – no matter how dedicated you are – often involves biting off more than you can chew without you realising it. The ‘plan’ invariably starts with pencil drawings over a dinner table discussion, and initially these blueprints seem like a cakewalk to construct, but it’s never that simple. Any studio, irrespective of whether it’s at home, in the shed or down the street behind the shopping centre, is a large undertaking, and in many respects it makes no difference where it is. Unless you can dedicate yourself to the task full time – particularly if it’s inside the house in which you also live from day to day – you’re almost certainly going to underestimate the time it will take, and potentially drive yourself, and those who live with you, insane.

So if you’re poised at the starting line contemplating a home studio replete with new walls, floors and ceilings etc – assuming you’re doing it all largely by yourself – be prepared for the long haul. Accepting this inalienable fact is half the battle.

As with anything like this, it’s important to enjoy the process along the way and always remember: if you’re in a position to build your own home studio (or commercial facility – if that’s your preference), whether it be 10 square feet or 1000, you’re one of the luckiest people on the planet. To be able to realise your dreams without starving in the process, or being bombed between takes, is a privilege. So enjoy it, don’t sweat it. (Note to self.)

Whatever you do, don’t work with straw bales in short sleeves!

If it wasn’t for this ute, the studio would be even further behind schedule. 50 bales was all it could carry on its back (along with a trailer).


As I’ve said many times throughout these infrequent articles, construction at The Mill has been two parts know-how and one part experiment. Nowhere is this more the case than in the choice of materials for managing the acoustics within the room.

Where I live, I was already lucky to have a substantial building on the property with great bones: large, strongly framed and with no neighbours close by. The task has therefore mainly been to get the room sounding good – a subjective mission in many respects.

With that in mind, most of this year has involved messing around with several acoustic treatments – in between issues of AT, wiring the patchbay and mixing projects. Although, from pretty early on, it must be said, the main mixing room has been sounding very good, thanks mainly (in hindsight) to its sheer size. Making the room deader, liver or more diffuse has been a relatively simple task, although the size of the room has demanded substantial quantities of most of the things we’ve bought and/or experimented with.

Some of the more recent acoustic treatments we’ve added are now permanent fixtures rather than temporary ones. I’m sick and tired of shifting things around and contemplating alternatives. The time for permanency is well overdue.

The newly-built back wall is currently in the process of being fitted with curved wooden plywood panels to create a diffuse rear end. For about a year I was reluctant to construct a back wall at all under the giant metal girder that holds up the mezzanine. This reluctance was two-fold: I was used to the space being massive – 12 metres long – and preferred the look of it as one big room, even though it was, in all reality, too large at that depth; and secondly I was still toying with the idea of fitting a quadratic residue diffuser under the girder, possibly even on wheels.

For many months I’ve had heavy curtains hanging under the beam to shorten the room visually, to see how it felt minus the back four metres, and also to get a sense of how a newly created back room might function as a green room/overdub booth once the wall was built.

Well, now the wall is up. Cat5 and analogue multicore have been run through the walls in anticipation of the back room being occasionally used as a recording space, and these will ultimately terminate at the patchbay. The mixing room still feels big at over eight metres deep and the extra room – which, at 4.3 x 7.8 metres is still large by any conventional standard – now doubles as the perfect entranceway, buffering the main control room further from the outside world by effectively acting as a giant airlock.

The new wall underneath the steel girder is made of 140 x 45mm flooring joists – like the external walls – with Yellow Tongue flooring and 13mm Gyprock Soundchek on one side (with Green Glue between them), and another layer of Gyprock on the other. 3.5R Rockwool is also packed in the wall cavity. It’s not been built to acoustically isolate the two rooms completely, simply to minimise the sound of TV and conversations that might take place back there. But given its mass, certainly the wall is no slouch at reducing sound transmission. Drums will be recorded in this room eventually too I suspect, but by then it might also have a floating floor… we’ll see.

Any lingering desires to construct a complicated diffuser like the one I built at Turtlerock Mastering in Sydney some years back are now a distant memory. A much simpler (and arguably more effective) diffuser system is being constructed from curved plywood deflectors of varying widths and depths. These will be far cheaper and less complicated to construct, and take up considerably less space, time and energy than the quadratic residue diffuser alternative. Rick O’Neil still jokes that I originally estimated the Turtlerock diffuser would take ‘about six hours’ – it finished up taking three weeks. Maybe there’s a pattern forming here…

Construction at The Mill has been two parts know-how and one part experiment. Nowhere is this more the case than in the choice of materials for managing the acoustics within the room.


The straw bales I originally intended to install last year in the front of the room took far longer than expected to acquire, which was another relatively major stuff up. There simply weren’t any readily available when the time came to make the purchase. I guess the drought had taken its toll on the supply chain, who knows. My mistake was to start ringing around for a supplier the day before I needed them. If you’re intending to buy straw bales for a planned project, start making enquires well in advance of the walls going up – unfortunately they don’t sit on the supermarket shelf like eggs, especially in times of drought.

Now that most of the straw bales are stacked in the corners of the studio (as some of these photos illustrate), I have another dilemma: how to ‘finish’ their outer surface.

Most straw bale constructions use various forms of render to protect the bales (and occupants) against elements like wind and – most importantly – rain. In the absence of some type of rendering material, conventional straw bale walls (if there’s such a thing) are virtually useless insulators when stacked in a single row like bricks. The wind travels through them with surprising ease. These rendering ‘sealants’ also prevent small critters from taking up residence alongside you without permission.

But of course, I’m not using bales for this purpose at all, and as I’ve recently discovered, the studio application seems relatively unique. I have yet to come across one other person using them internally specifically as acoustic wall treatments – though others must be out there.

The thing is, the raw bales stacked in the main listening room without a covering of any kind, have improved the room dramatically. The sound has become tighter, the RT60 value has definitely dropped (though I haven’t yet measured it with any accuracy) and the speakers are more vivid than ever before. It’s quite amazing. For the 400-odd bucks it has cost me so far, they must surely be the cheapest acoustic treatment – pound for pound – of any material, and also one of the best.

The problem is that even though they’re inside, in their raw state the bales shed straw at the drop of a (stetson) hat, attract mice like the pied piper and look like someone preparing their marquee for a barn dance. Maybe if I was exclusively mixing country music I might get away with it but as things stand, it currently looks a bit silly… and then there’s the smell. Hayfever sufferers beware.

The trick will be to find a way of sealing the bales against shedding, mice and white tail spiders without creating a hard shell on the surface that will liven them back up and reflect (albeit fairly randomly) lower and lower frequencies as the render gets thicker. Ideally, I want to leave them raw to maximise the benefits of their amazing broadband absorption qualities, but there’s no getting around it, I have to seal them with something. What this might be is as yet undetermined. It might be clay, gypsum or cloth… possibly even just PVA glue, as one experienced strawbaler has suggested I try. Whatever I do, I have to do it soon… spiders are moving in faster than you can say ‘arachnophobia’.

The new wall underneath the steel girder is made of 140 x 45mm flooring joists – like the external walls – with Yellow Tongue flooring and 13mm Gyprock Soundchek on one side (with Green Glue between them), and another layer of Gyprock on the other. 3.5R Rockwool is also packed in the wall cavity.


One commercial product I’ve added to the acoustic mix (which has already been named ‘the big black cloud’ by one client) has already significantly reduced the amount of time this project will ultimately take – a bank of 12 RPG ‘Skyline’ diffusers above the console (see picture). In the past I’ve used timber in this arrangement, but with a few of these tedious escapades already under my belt – where several hundred blocks of timber were cut into specific (or sometimes non-specific) lengths – this time around I was more than happy to go with an off-the-shelf product. The Skylines sound great, weigh virtually nothing (being made from polystyrene), and have tightened up the reflections off the roof considerably.

The downside of these types of products is really only their cost. They’re definitely at the more expensive end of the spectrum and if I’d paid full price for them (which I didn’t) or needed to cover a larger area, I would have been up for a significant wad of cash. One thing’s for sure, they work – unlike some of the other prefab acoustic treatments. The other benefit is that they look great and install easily with flathead nails. A word of warning about this however: sticking polystyrene Skyline diffusers on the roof with double-sided tape is a dead loss. It might be a good temporary fix while you’re reaching for the nailbag, but don’t expect them to be there when you return the next day. I lost three in two hours when I first installed them.

If you’ve got the dosh, the RPG Skylines are a great way to advance your room treatment quickly and easily. They sure beat spending countless days cutting timber blocks, sanding and fixing them to back plates and finally working out how to attach the total weight to an unsuspecting roof. If I could afford more of them, I wouldn’t hesitate.


The biggest challenge ahead for The Mill is to reduce its carbon footprint to something that fits into my shoe rather than causing nearby farmers to report possible sightings of a Sasquatch.

I’ve been running my Neve console, various outboard units, computers and powered monitors etc for some time now and, on average, the property uses quadruple the power of a typical household – yikes! In this day and age this amounts to coal-collar crime in my opinion, so I’m urgently in the throes of forming a solution that will reduce my footprint considerably by virtually eliminating the property’s reliance on an outside power source. Within about two months, all things being equal, I’m hoping to have a bank of 12 batteries, solar panels and a 2.5kW wind turbine installed on the property that my electrician estimates will effectively power the whole property, including the house. I’ll report more on this after the blades are turning and the panels baking. Suffice it to say, the prospect of the house soon being electrically self-sufficient, even with my hungry audio devices switched on, is very exciting.

At the risk of sounding like a preacher at this point, I think it’s high time mainstream society came to the understanding that there’s really no such thing as a ‘Greenie’ any more. Either you give a damn about the future of our planet or you don’t. I, for one, don’t think we have the right to leave nothing but pollution in our wake for the sake of better EQ and an improved front end. It’s always been my dream to build a self-sufficient house and hopefully this is now about to become a reality. One of my neighbours has been living happily off the grid since 1971, so the idea is hardly new. If you’re using significant amounts of power – and some studios use a daily average of about 50kW hours – just imagine what it would be like if the chimney stack from the coal you burn fed back into the studio. It wouldn’t be long before you’d need a seeing eye-dog to navigate your way to the exit. We need to clean up our act.

To that end there’s currently a Federal Government rebate on the table that will contribute a financial subsidy to most households looking to reduce their carbon footprint. I’d encourage everyone with a roof over his or her head to look into it. If you’re interested, find out if it’s relevant to your circumstances by visiting the website:


One of the original ideas behind this series of articles was to hear from AT readers who have made similar efforts towards improving their home studio environs. We’ve already highlighted a few, but now we’d once again like to hear more about what’s going on at your place. If you think your spare room or garden shed has been transformed in a way that might be of interest to others, please don’t hesitate to drop me a line. Next time around I’d like to highlight some of the inventive ways others have approached their home studio fitouts. Email me:

As I sign off I can hear a mouse rustling inside the straw bales at the front of the room – I kid you not. I might have to buy some traps…


In this, the third installment of Andy Stewart’s home studio construction story, we look at some of the do’s and don’ts of practical acoustics and ‘fire up’ the Neve console – it’s all grist for The Mill!


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Issue 91