Computers for Production Recording

In almost all production recording systems some kind of field recorder is used.  In most of these cases they’re actually a very specialised computer running a cut down operating system (usually a Linux kernel or Windows Embedded variant) with custom software.

For example, I’ve found my Tascam HD-P2 runs Windows CE (it’s mentioned in the version 1.05 release notes).  As a you start to think *OMFG my recorder will BSOD on me*, a lot of the problems with Windows (and other OS) is when things get changed, and systems have to deal with this.  Usually with embedded systems this isn’t the case, they’re ‘sealed units’ and run all sorts of systems which cannot tolerate failure like aircraft autopilot systems and industrial automation systems.

Why not run a specialised computer for recording purposes? It’ll be much cheaper, right?

One of the main issues is software.  Although there are quite a few programs for multichannel audio recording and mixing, most do a lot of things you don’t need for production recording (which means more to go wrong) and some don’t do some things you do need (metadata editing and Time Code input).

The best course of action would be to use a piece of software designed for this purpose, AFAIK there are three (prices include VAT):

Boom Recorder (Mac OSX only) £175
Metacorder (Mac OSX only) £1314
SADiE MTR (Windows only, with SADiE Hardware) £4100 with LRX2

You also need an interface to get the audio into the computer.  Here’s a list of those which I’ve found which have at least 8 inputs and a DSP routing system, can be powered by DC in the field

Interface Price Weight (kg) Dimensions (mm) Power Consumption (W)
RME FF UC (USB) 722.73 1.5 218x44x155 13
RME FF UCX (USB/FW) 958.26 1.5 218x44x155 13
MOTU Traveler mk3 (FW) 589 1.73 375x44x229 ?
Metric Halo 2882 (FW) 1215 2 343x44x279 8
Sadie LRX2 (USB) 4100 6 330x65x423 50

Now you’ll need a computer to run it.  I initially had ideas of very small industrial machines with no moving parts and Atom/AMD Fusion CPUs.  These would work fine with the SADiE system (in face any machine with a hard drive fast enough should, as the LRX does the heavy lifting), but I’m not too sure about running OSX on them.  In addition to this the RME USB interfaces don’t work too well with Atom machines (and haven’t been tested with the AMD chips).

Having a look round for a small computer which will run off DC power, not have an atom processor and run OSX it looks like you’re looking at a Mac or a going for a ‘hackintosh’ job (installing OSX on an non-apple x86 machine) on a similarly sized ‘ultrabook’ (which would cost around the same for the base machine).  Prices are given with 15% discount (either as a refurb or through a number of discount schemes, education etc). I’ve discounted the low end Macbook air as I don’t think 2GB memory will cut it:

Computer Price (£) Battery life (Whr) Power consumption (W) Weight (kg)
Display off Display on
Macbook Air 11” i5 4GB 128GB 850 35 4.2 9 1.06
Macbook Air 11” i7 4GB 128GB 970 35 4.2 9 1.06
Macbook Pro 13” i7 128GB SSD 1172 63.5 7.2 12.7 2

Another thing which will need to be added to the system is a TCXO clock, if time code sync is required (clock on LRX2 will probably suffice).  Here are some options:

Denecke SB3 £384
Timecode Buddy Master £810.00
Ambient ACL203 £690

In order to use firewire interfaces with the Macbook air, you need some kind of thunderbolt adapter.  The cheapest current method is (this means it’s actually cheaper to use an RME FF UC with Macbook Air):

Sonnet thunderbolt to expresscard 123.60
Thunderbolt cable 39
Expresscard to FW 16.78


In order to create mixes you’ll also need some kind of mixer or control surface.  If you’re already running a mixer in front of your recorder you can probably make do.  For drama/ cart based setups the only option I can see which runs from DC power is the Avid Artist Mix (formerly Euphonix MC mix) at £1000.  On the other end of the scale there are a few USB powered things with knobs/faders on from Korg and Akai, which may break from just looking at them

Control Surface  Cost (£) Weight (kg) Dimensions (mm)
Avid / Euphonix Artist Mix 1000 2.2 238x30x420
Mackie MCU Pro 1000 7.6 419x119x423

Bag setups *may* be feasible by putting the laptop at the bottom of the bag, the interface where the recorder would normally be and using a small touchscreen monitor for control: eg Lilliput 669GL

Finally here’s a few example packages you could put together here  The LRX2 price is taking into account using an existing laptop, adding the 16mic pre card and 25% discount for part ex with old SADiE kit (can be found on ebay for buttons):

Price Weight (kg) Power Consumption (W)
Cheap (MBA+FFUC+Monitor+Denecke+BR) 2287.73 2.56 17.2
Drama (MBAi7+FFUCX+Avid+Denecke+BR) 3487.26 4.76 17.2
Lo Power (MBAi7+MH2882+Denecke+BR) 2941.03 3.06 12.2
SADiE LRX2 (USB) 4500 8 50
Sound Devices 788T + CL9 6953 3.8 16


Here’s a comparison of different systems taking into account cost, weight and power consumption.  I haven’t added the monitor power consumption- it’s around 8W, assuming you may also use one with a  788T system. I believe the LRX2 can actually display sync video on screen.  I also don’t know the power consumption of the Avid Artist mix

Selling Stuff

I’ve had a rummage through the cupboards and I’m looking to get rid of a few bits I rarely use, or have meant to get fixed and haven’t.  Open to offers on all

Doepfer Regelwerk Discontinued MIDI/CV sequencer/fader controller SOLD


Yamaha DX7S 80’s classic with a few tweaks.  New internal battery fitted £200

Panasonic NV-MX300 small 3CCD DV camcorder- doesn’t play nicely over FW with MS Windows (firmware bug) £200 SOLD

Commodore MK10 mini-key MIDI keyboard £15
Really light midi controller keyboard, great with small synths/samplers without keyboards.  And gets bonus retro points for saying Commodore on

Sennheiser ME3-ew Headset mic £50
Part of the Sennheiser ew135 system, as recommended by Alan Partridge.  Needs 5V plug in power.

Behringer Ultra DI800 8 way DI box £50 SOLD

Roland D-110 multitimbral sound module £40
Volume knob missing

Roland SP-404 (broken, won’t boot up) sampler good condition £50

AKG C535EB Condenser mic (broken, no signal + paint come off) Nice when working… £30


Mackie 1604 rackmount rails, unused £15 SOLD

Clocker / Counter

Here’s a video of me performing an adapted version of Alvin Lucier’s Clocker at Bang the Bore X: Zone of Alienation

Instead of using a clock, we substituted it for a Geiger-Muller counter and radioactive source: Thorium 232.

Equipment used:

DIY Galvanic skin response sensor
Tapco Blend 6 Mixer
Roland SDE-3000 Digital delay (has control voltage input)
Coutryman B3 Microphone (to pick up the counter’s speaker output)



Large Feedback Instrument #2

From last time I’ve now managed to get some new IDC headers to replace the broken ones, so went about reconstructing the ribbon cable.

I also gave up on the idea of getting an A-gauge patchbay and soldered in the aux sends to the back of a 96way bantam patchbay as shown here:

as there was only one 0V reference I had to get a wire and bridge it across all the other connections.

I also wired in 8 jacks to feed back the signal into the mixers inputs.  I decided to leave the connections open too, although I considered having them normalled (see this article for patchbay configurations) which would be mental (all signals would be feeding back all the time).

Now to fire it up again and see if there is audio…

Unfortunately I’ve only got 2 bantam patch leads (this might get expensive to remedy). But running 2 channels and 2 auxes it sounds like this (go to the end for animal sounds):


Large Feedback Instrument: Test 1 by richard-thomas

DIY acoustic equalizers

In February I recorded a fantastic concert (review from The Watchful Ear) put on by Bang the Bore in Southampton.  It was located in the Castle Vaults, under the town centre and consisted of a performance of Alvin Lucier’s classic, I am sitting in a room and a top form set from John Butcher who does things with a saxophone which must be heard to be believed.

As a large part of what was going on in this gig was reacting to the space (John Butcher has an ongoing ‘Resonant Spaces‘ project), I thought I’d try and record as much of the room without it getting too muddy.

Omnidirectional microphones, pickup the most room sound but need to be placed within the critical distance (closer than the with directional microphones) to receive more of the direct sound from the performer rather than reflected sound from the walls of the room.  I was looking at recording outside the critical distance, in the diffuse field (where there is more sound reflected from the room) so needed to improve the directivity of my microphones but retain the flat frequency response down to low frequencies that the omni’s have.

You can do some of this using EQ on a mixer.  Alternatively you can affect what happens to the sound before it gets to the microphone by creating a reflective baffle around the microphone, which I intended on doing.  DPA already make these for their microphones, but they’re £75 each (ow!) and don’t fit my AKG’s.  So went out to the local shops in search of foam balls…

I came back with a pair of ‘Dog Balls’ from “Magic Prices at Just Jeff’s” (yes, it’s really called that) and an apple corer.  Total cost was under £3. And lighter than a mixer 🙂

Unfortunately the apple corer wasn’t the best tool for the job:

however (with some pain and awkwardness) did get through the balls *ahem*.

and managed to squeeze a microphone through:

although they did look a bit silly they did do the job, however the room wasn’t as reverberant as I expected.

I’ll see what’s happening with the recording- if it gets put up somewhere I’ll add a link



Large Feedback Instrument #1

I do quite a bit of mucking about with no-input mixer setups, it’s usually my little Tapco Blend 6, but started running short of Aux sends (independent outputs from the main output on a mixer) and started thinking of what you could do with more…

I had a look round and the only mixing desks you could readily get with this were desks designed for monitor engineers and they were big, or there’s the A&H Mixwizard 12M which looks just about ideal, apart from the price. I had a look into matrix mixers (which are essentially just aux sends) and found either were no longer available in the case of the Mackie/Oz Audio HMX-56 or again expensive (Midas XL-88)

Looks like it’s a homemade job then…

I’d been looking up matrix mixer schematics and experimenting on breadboard until I came across some input modules on ebay (NOS) for a DDA CS12 monitor console, for not much money at all (and the schematics are online).  Ended up buying 2 of them (8 channels each). They have 12 aux sends per channel (more than enough).

Then looked into sourcing the stuff to make them work which was quite a bit more difficult.  Found each channel is connected up and powered with a ribbon cable, which happen to be the same connectors as on a floppy drives (great!). But I needed at least 8 nodes and a way of hooking them up to a power supply (needing +18V 0V -18V and +48V rails).  DIY job. Bought an IDC crimp, some lovely retro rainbow ribbon cable  and some IDC headers (which took 3 months to get here from China and most parts were already broken…)

And I needed to power the thing. Replacement linear power supplies for mixers like this are big, heavy and expensive things and I wanted the desk to stay portable.  You can’t usually get switching power supplies with two rails (or at least I couldn’t find any), so instead I bought 2 18V PSUs and wired them so 0V on one and +18V on the other were soldered to the same plug, making that 0V, so 0v on the ‘low’ power supply was now .  An XLR seemed to be the only 3 pin connector I had handy so soldered them to this (let’s hope I don’t ever plug this into a mixer or similar.



After counting (and double checking) the number of each strand on the ribbon cables (the rainbow effect was very handy), I separated out all those connected to power and put them on another XLR.

After also crimping on 8 IDC headers and plugging them into the PSUs they started making a bad clicking noise.  Something was shorting out.  After going through the XLR connections multiple times to make sure something wasn’t touching it turned out one of the crimps wasn’t in line and was shorting out adjacent cables.

After the cable was taken apart and put together I found most of my IDC headers were now completely broken…  Fortunately one was left so I plugged it in.

It’s alive!

Next steps are (when I’ve got more headers) sorting out the outputs.  I’d got hold of a Mosses and Mitchell B-Gauge patchbay I was going to use for this (with patches going back to the line in), but on second thoughts everything it’ll be plugged into will use A-Gauge jacks so might get one of those instead.

Cabling and Commerce

Recently I’ve been making quite a few cables, including my own camera umbilical and tails. This has been a new adventure into soldering smaller connectors with more pins, but it’s no more difficult than putting standard electronic components onto a board really. The scary thing is paying over £10 per connector in some cases.

Anyway, after I’d bought 100m of mic cable and some connectors in bulk I thought I’d offer some to friends for a reasonable price. As that seems to work I thought there’s nothing to lose in offering it to the general public, so here’s my shop.

It’s all good quality stuff (same that I’m using), Neutrik, Hirose, Switchcraft etc connectors, nice flexible cable

After a few requests I’m also doing contact microphones and coils. Contact Mics are sealed in Plasti-Dip (Nicolas Collins style), so should last a bit longer and be slightly waterproof (although I can’t guarantee this)

There should be most common configurations of cables and connectors up there as options, but please send me an email/DM for any custom requests. I’ve also got an IDC crimp so should be able to do replacement ribbon cables for things like Mackie mixers and Pro Tools TDM connectors


Since starting to do things involving cameras as well as microphones, there are situations where you don’t only have to get the microphone in the right place, but hide it too.

From recommendations mentioned on for the last couple of years I’ve been using Manfrotto 5001B light (as in holding up lights) stands for microphones, as they’re small and lightweight and can extent up to almost 2m

It just so happens that there’s masses of equipment designed for getting cameras and lights in the right place.  Fortunately (and usually just with a 5/8″-3/8″ adapter) you can also use them with microphone mounts too.

Some of the more useful things seem to be the Magic Arm (Manfrotto and Arri do one):

this has two ball and socket joints on either end which lock in place when the cantilever is tightened.  You can attach it to other stands and objects with clamps or attach it to a backlite base and use it like a (more flexible) low boom stand.

For lighter loads the Flexible arm will do a similar job

Also, if you need to attach microphones to flat surfaces (or wish to climb skyscrapers, human-fly style) here’s a dubiously named ‘Pump Cup’.

Basic Location Kit

I’ve recently had quite a full-on, but really enjoyable and informative week at the NFTS doing their location recording short course under the tutelage of Mervyn Gerrard.

One of the things that I’m looking at is what kit is required for location work for video, here’s some stuff I’ve gathered from the course and various forums etc:

1x Field Mixer

This is a similar piece of kit to any other audio mixer, except they’re made to be operated from a bag (therefore battery powered and light) and most can probably survive being run over by a van.  Most also have high quality and  clean preamps (which also may lend themselves well to recording acoustic music) and very good limiters (you need these).  They are also the heart of all your routing and monitoring, you can send feeds to recorders, camera and also monitor returns to make sure it’s being recorded.  Mixing for dialogue can be quite a different kettle of fish to music, in order to minimise background noise and to keep a relatively high level you need to switch between microphones quickly, anticipating who is going to speak next whilst keeping a constant level of background noise.  It’s also rare that you actually mix to stereo (only usually for fx).  Most dialogue is mixed to two mono tracks.

2x Boom mics

This is the way you’re going to get the best quality sound and the only way you can achieve a sense of auditory perspective as you can change the microphone position with the camera shot.  Typically you’d want to have a hypercardioid microphone (picks up less reflections indoors) and a short gun microphone which has greater rejection of sound coming in off-axis, although if one fails you could use the other.

As for booms, you generally want the lightest possible boom of the length that is likely to be required for the shots you will be involved in.  Longer booms require a separate boom operator for two handed use.

You’ll also require a suspension and a windshield (foam will do for indoors) to reduce noise from moving the boom pole around.

These microphones may also be planted (hidden amongst props) or used from fixed stands if the subject is not moving

3x personal mics
2x radio transmitters/receivers

These are small lavelier microphones which can be connected and hidden in a person’s clothes. They are usually omnidirectional so pick up sound from all directions.  They are usually used when there would be no way of using a boom or plant microphone as they provide a close perspective at all times.  They are often used in conjunction with radio transmitters and receivers- it’s an important point to remember that radio transmission (even though it can cost over £2000/channel) is less reliable than a cable.  Radio systems with full diversity offer a higher level of redundancy to those without.  It’s also best to have a spare lavelier microphone in case of failure.

2x Headphones

These are your only way of hearing what you are recording, get a closed back pair so you can block out sound from outside (and don’t get any with noise reduction- it’ll process the sound you are recording).  Get a spare, if they fail you’re in trouble.

1x Bag

You need an easy way of carrying that stuff around with you so you can operate it and access cables easily.  Here’s a video on a basic sound bag from B&H (big shop in New York run by orthodox Jews).


Make sure you’ve easily got enough to cover the day- there are also centralised power options (often based on NP1 batteries), although you can also buy a Li-Ion battery and sorting the cabling out yourself.


Depends on your workflow but a separate recorder can be useful for a backup and wild tracks.  If you’re working on a separate system to video it’ll have to be syncronised.  This can be done with timecode jam sync boxes (if the recorder and camera support them)


Here’s the boring (and heavy part).

You’ll need all the cables to connect up your mixer to camera and/or recorder (usually a Hirose/Tajimi umbilical with detachable tails), plus:

4x long XLR cables (around 10-15M, for plant mics and feeds)
2x short XLR cables (3-4m for boom)

Adapters (it’s likely that you may have to plug into unexpected equipment) :
2x Minijack/Jack-XLR
2x Jack/minijack-RCA
XLR “Y” splitter

+ -10 to -60db XLR pads and ‘sex reversers’

Toolkit- Multimeter (cable and equipment testing), toolkit- screwdriver, pliers etc

1x Boom Stand
1x Magic Arm (grip equipment for attaching microphones to light stands, chairs etc)