Truck box body as control room

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Tubetec

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Joined
Nov 18, 2015
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5,951
Im hatching a plan to build a small studio mainly from recycled stuff ,
I'm going to get an old refridgerated box body and set it down on concrete supports ,
The beauty is its aluminium on the outside so its stops any air borne interference ,
The insulation is incredibly good both sonically and temperature wise .
Its easy to cut slots and add upvc windows or doors ,
It wont be difficult to add the usual mobile studio style paneling on in the inside .
I should be able to pick it up cheap without a working refridgeration unit ,probably around 500-1000 euros including delivery .
The footings I can throw up myself ,it need only be a course or two of blocks with a small foundation underneath .
Turning the roof into a solar panel and having a battery box underneath sounds like a plan . I can suplement the battery charge with mains power at off peak hours for a 50% discount .
The idea of a vibrator based 230v supply came to mind , maybe a car starter motor driving an alternator into a step up transformer again all easy stuff to get from the breakers yard .1663454689533.png
 
Lots to like but acoustically this is a very bad time. Height and width basically the same, and the length looks like close on double that. This means modal issues will stack badly and you don't have the width or height for LF treatment to tackle the issues effectively.

I've treated many rooms with similar dimensions and the result was always sub standard IMO.
 
Good to hear from you Ruairi ,
A small partition housing a few tape machines , PSU's and other stuff with fans will change the dimensions , but yeah at low frequencies there could be a problem if your sourounded by metal on all sides . Making the opposing wall and end wall acoustically transparent at low frequencies could solve it

edit the back wall of the container will be behind the partition , so any longitudinal waves will have a tough time reflecting . Obviously calculations matter in terms modality , so very gratefull for any help on the mathmatical side .
 
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Fortunately the place where the container will sit is very well sheltered with tall trees to the south west and a wall to stop the wind getting underneath .
There have been a few people blown away off cliffs in their caravans here alright , I'll definately make provision for easy attachment of ratchet straps in the case of once in 100 year weather events . Everything can get anchored down to the footings which will be made from bricks and mortar and planted down into the ground .
Of course the other thing I could do is just buy an older refridgerated truck and park it up in the same spot ,
I could have a mobile studio then as well . probably more like 5-10 grand for a truck with a bit of life left in it.
 
Nice!

Is the idea to have it transportable, or will it stay in place?

If you want a real vibrating PSU, I've got one around somewhere. It worked, last time I checked. It's only 50W or so. Just to save you building a big one, in case you were serious about it :)
 
Id definately consider buying a truck if something came up at the right price .
I allowed my driving liscence to expire years ago though ,now I'd need to start again from scratch before Im on the road again .
I guess I could just get a modern electronic invertor supply , but the pure sine wave invertors are quite costly and Im not sure about the quality of the power they generate .

Should be easy enough to figure out an air supply , making it silent in opperation might take a bit of work alright .
 
The dimensions look like they could be close to a 1:1: 1.5: 2.5 ratio. With the thin walls it could sound good in there.
 
The usual vibrator supply is probably based on relay contacts chattering on and off , thats noisey and is bound to give a spikey waveform , I was thinking more like rotary power generation , A starter motor a fly wheel and an alternator , I know an alternator spits out a three phase waveform , is it possible to step that up via a transformer into a single phase supply ?
Its purely electromechanical so no electronics to go wrong , it could be housed away from the box body so the small noise it makes would be irrelevant .
I'll start off with regular mains power to begin with but make provision for a battery bank and AC generator later . I wonder what frequency an alternator spits out , varies with engine revs of course . Could anyone into their cars have a look at the alternator with a frequency counter for me ?

As far as I know the fridge box boddies are an aluminium shell with pumped insulation in the cavity , theres an old yard out the road a mile or two where a guy has loads of scrapped commercial vehicles , I might call out there for a look around .
 
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I found this example of a rotary power convertor , not massively powerfully and it puts out DC so no good . I wonder is there a similar contraption that puts out 50-60hz AC at 230 volts from a 12 or 24 volt DC supply .
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Just make sure it's not an old fish truck. They're cheap because you'll never get rid of the stink :giggle:
I once helped a friend build a mobile studio in a mid-size camper. Solar power and he lashed out a good chunk of change on a good sinewave inverter. He took it with him to Iceland and disappeared. For all I know, he's still recording music out in the lava fields up there...
 
He might have fallen in love with a little snow pixie up there or something .
Ironically I was down the local pub last night , turns out the landlord has an old fridge lorry out in his yard ,
I'll get to have a look at it soon .

Im still in two minds about making the thing mobile or not , one major plus with a mobile set up is if you have any complaints from the neighbours to the local council and they tell you to move it , you can at least tow it away then bring it back 24 hours later ,then you get another year before a complaint can be lodged again . Its whats known as a de-mountable structure , it applies to caravans mobile homes campers etc
I do like the idea of location recording also though , it could certainly open up other avenues and jobs down the line .
 
Forget about using a starter motor. Bad efficiency and not made for continuous duty.

Solar and batteries seem easier, maybe even cheaper. Only, no solar cells on stock atm.

I once considered a +/- 24VDC setup. Enough to feed most mixers, even power amps. Add a third small 24VDC battery set for phantom power. No AC in sight.

I used a portable DIY recording setup on 12VDC 4Ah for a long while. Worked well, as the battery could be charged from 12VDC too.

If you really want to keep it mobile, weight is an important consideration.
 
I ASSume that Ireland doesn't have high wind events like we have here in central USA? Severe storms here frequently topple "manufactured homes" aka trailer houses.

Bri
Isn't that why we call them MOBILE homes Brian?


My biz partner tracked a very well known rap/hip-hop or whatever artist from a live truck outside the artists home in LA. They had managed to squeeze an SSL-4000 series in there. The truck was acoustically treated of course - had balanced power, and all the finery's of the time. It is honestly my biz partners near dream for a tracking and mixing area other than the sonics - he loves being in dark caves. I fricken hate it. 56 years of dark is enough.

Now, the studio he is based in- is just opening and has lots of natural light and looks out over the intracoastal waterway here in South Carolina, USA... Not a bad day-gig. Lots of natural light and old wood - he is happier than ever - and honesltly he is normally a grouch. That said, there was no way he was going to mix in there, unless at extremely, extremely LOW volume. it's a shoebox with wool.

That said, you can make it work, and it is better than nothing in spades! (and I highly encourage you to try if you have no other options). Also DOING STUFF, rather than DREAMING will earn you big points in life! Maybe the 3 business rules apply here? A friend distilled his 4 years for a business degree into this for me:

1. Something is better than nothing
2. More is better than less
3. Sooner is better than later

Best of luck, I would love to see what you choose to do. Our mixing area here has a floor to ceiling 1.2 meter thick layer of rigid mineral wool, spaced 1 foot off the wall it is near, which is also covered in mineral wool. That is the full width of the room floor to ceiling. None of the walls in the room are parallel including the ceiling. We also knocked out all of the sheetrock on that floor to give the room larger dimensions that it really had (where you could sit and put gear). It allowed for low end waves to properly propagate.... well we think. it gave us some 40 (12.2 meters) feet of relatively unobstructed space for waves to develop. It sounds great. From in front - where the wall of wool is, noting comes back or out of it, just the barefoot monitors output. Very happy with ruining my house for it. Hard to beat doing award winning work from you house.
 
Parallel surfaces ie square or rectangular rooms dont diffuse sounds in the same way as those with no parrallel walls , flutter echo is the issue , pull out all the soft furnishings from your standard box room and see how it sounds , clangy at best , but thats typically concrete/ sheet rock construction , while a skin of aluminium will reflect horribly at higher frequencies thats a matter of providing enough depth of absorbant material to effectively stop reflections at those frequencies , but it wont act the same as super rigid and heavy concrete walls at low frequencies either .
I take the point that , lets call it the front wall of the control room wants tons of lagging , to stop the speaker boxes throwing out reflections that arrive to the ear mS after the initial sound ,time smear .
Im thinking highly absorbant walls at high frequencies ,but see through at LF front and back , now the LF wave gets to propagate longitudinally beyond the confines of the box itself instead of rattling back and forth between two immovable surfaces , in any case its going to be much better than your standard box room in a house made of bricks and mortar.

As far as the rotary supply goes an unloaded starter motor will only draw a fraction of the current of one that has to crank an engine round , alternators rotate freely untill the windings are loaded down , a fly wheel could provide the kinetic energy to over come high inrush current at switch on , ok it wont be as efficient as a top spec invertor ,but as I said earlier its purely electromechanical so theres very little to go wrong ,where your high spec invertor will inevitably throw its toys out of the pram a few years down the line and quit on you . The point Im trying to make is I can get a starter and an alternator for next to no cost ,who cares a damn about a handfull of %age points loss in efficiency over a box of solid state shit thats costs you thousands .
 
I've tried starter motors. They eventually run hot when loaded. Some run even hot and burn out with no load. Some also add a spark transmitter to your power chain.

Some of the inverters I use are over 10 years old. None has failed yet. Some were saved from the scrap.

It's also not the efficiency you need, but a system to prevent draining the batteries to death.

And any way you go, it's the batteries that cost the most and have the most limited lifetime, unless you go LiFe.
 
I think the issue with using a starter motor is they are designed for a very low duty cycle. I have a hard time imagining that a starter motor would survive being under load for any continuous load. I mean just look at the cooling design of a starter versus a comparable output continuous duty electric motor....
 

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