Tag Archives: location sound

ESPYS Video “Pat Summitt”

Here’s a link to a production I worked on for ESPN on Pat Summitt:


I made two trips to Knoxville for this production, once to shoot Pat Summitt’s final home game, and once to interview Pat, her son Tyler, and her assistant coach Holly Warlick.

Producer Becca Gitlitz interviews Tyler Summitt for the ESPSY video

My favorite off-camera bit was when Pat and Holly were chatting about her earliest coaching days, and how the team was called “The Corn-Fed Chicks…” It was certainly a different time!


DP Christian Hoagland adjusts his background… it’s just a bunch of shiny wire with bits of metal hanging off. When thrown out of focus, the effect is rather nice… see the video above for the results.

A DSLR Timecode Workflow

Most of the DSLR shoots I’ve worked on have been fairly simple affairs, at least in terms of synchronizing the sound… mostly because there weren’t any other options. These shoots are done old-school “double-system,” where the camera records the visuals and the audio is recorded with a separate recorder. We used to use a Nagra for this (which is still a desirable piece of gear… one day I’ll find one that I can afford.) A standard slate is used at the head of each take to provide a marker for the editors. They line up the little bar of the slate with the crack of the slate’s clapper on the waveform, sliding the audio around until they match, and then the audio is locked to picture. Many folks are using PluralEyes to speed up this process. But if you’re doing a long-form production with a lot of takes, manual sync can become a fairly large chore.

The Ambient Lockit Buddy in the hotshoe mount

I did a shoot recently where the production house supplied an Lockit Buddy (built by Freelance Audio Visual Services in the UK) along with an Ambient Clockit Box (we used an ACL 203) timecode generator. Ambient timecode generators have been around for a long time, and are proven pieces of kit… though they are expensive little morsels. What’s new is the Lockit Buddy. This is  a small passive device designed to drop linear timecode down to mic level, allowing it to be recorded on the DSLR’s right channel. You can also feed a reference audio track to go on the left channel, if you have an extra wireless or line level out. The Lockit Buddy doesn’t generate its own timecode, and requires some sort of timecode signal for it to work… either generated as it was on this shoot, or a feed from a timecode out from a timecode-capable audio recorder (My Edirol R4 Prohas a BNC timecode out that would be perfect for this application, but the DP didn’t want to be tethered to my recorder) or a video camera.

A typical Lockit Buddy setup. Note that there’s no provision to mount either the wireless receiver or the timecode generator… not ideal for handheld shooting or tight production schedules

In use, the Lockit Buddy worked pretty well. We would jam sync the recorder at the beginning of the day and then disconnect the two (with both the recorder and the master generator running in “free run,” of course). The generator and lockit buddy combination was a bit cumbersome on the camera. The Lockit Buddy comes with a hotshoe mount, but not the lockbox, so we had to tape everything on top of the camera. The assembly was  constantly slipping out of the hotshoe mount. Because of the mounting difficulty, we didn’t use the wireless receiver on the camera. But it did work. I’ve even got my own Lockit Buddy on order, as they’re not too expensive (around $140).

setting the sound recording level manually is required for the timecode signal to work, though the constant level of LTC would likely override the audio gain setting of the camera. Sudden loud bursts of noise may cause the level to fluctuate in auto mode, however, causing potential sync problems.

Unfortunately, the post work is being done in the UK, so I can’t report how seamless the system is on the backside. I understand they “had some trouble syncing up the takes,” but they didn’t elaborate. Still, if a scratch audio track is fed to one side, one could still use PluralEyes if the LTC signal somehow failed to lock up. Using a slate is, needless to say, mandatory. And there is more info about the post process on the Ambient website.

While I like the Lockit Buddy, there are some improvements that I’d like to see… maybe in version 2.0. A full-sized XLR connector with a mic/line selector switch would be a big improvement, and wouldn’t require any active circuitry.  This way a DP could plug in a basic mic for an audio scratch track, without requiring a tether to the soundperson. The TA3 connector means that special cables must be built to get audio into the camera, and an additional 3.5mm female jack would be highly convenient. I may do that modification myself, once mine arrives.

How To Make Turtle Clips

I can hear you. You’re saying, “What the #%*& is a turtle clip?”… a reasonable response to the above headline, actually. I didn’t know about them myself until recently. A “turtle clip” is a mic clip with a little wire bail over it. The wire is there to keep fabric away from the mic, preventing clothing rustle.

A commercially available turtle clip for a Tram lav

If you’re flush with cash and short on time, you can buy these from B&H for $20 apiece. Or you could make them yourself. All you need are some bits of copper wire, something round (like a dowel or broom handle) to use as a former, a pair of needlenose pliers, and a pair of cutters. Optionally, you can use a soldering iron if you want to get fancy, but it isn’t required. The clips that I made require a bit of Topstik or Moleskin to secure the mic, but they work as well as the ones from B&H.

Any round object will do as a former. The size determines the diameter of the finished mic clip… about a half-inch or three-quarter-inch rod will do. Wrap the wire around the former as if you were winding a spring one and a half turns. It’s easiest to wind a little extra and then clip off the excess wire later.

Starting a turtle clip. Copper wire is wound around a round former, 1 1/2 turns

Now, using the needlenose pliers, bend a half turn of the wire up 90 degrees. Clip off any excess wire and you’re done, unless you want to solder the ends. Soldering only takes a second and does make the finished clips a tad stronger and smoother, but it isn’t required. If you haven’t done much soldering before, this step could be

Bend one of the loops 90 degrees. I used a vise, but pliers can work fine for this.

a little tricky, but it’s very easy with a little practice. (HINT: Heat the wires first, then apply the solder to the wires. Don’t apply solder to the soldering iron, except maybe to help transfer the heat to the wires.)

Once you’ve made a few of these, other variations and improvements will surely come to you…

Snipping off the excess wire. Having a little extra wire makes handling these a touch easier while you make them.

making clips with two bails, for example, or rectangular shapes rather than round. They will get rather bent out of shape with regular use, but they’re easily replaced and cost only a little time. And if you’re too busy to take the ten minutes it takes to make these, I’ll be happy to sell you some that I’ve made… only twenty dollars each!

My collection of homemade turtle clips. They didn't take long to make, and they get easier with a little practice.

Comparing Lav Mics

I don’t have a huge collection of lav microphones, but I’ve tried several different models over the years. All of them work amazingly well, though I’ve naturally developed a preference, and I do have one particular model that I tend to use as my “go-to” mic (which I’ll reveal in a moment).

Some wired lavs- from left to right, unmarked EV lav, evCO90, Sony ECM44b, Sony ECM55b

The problem with comparing different lav mic models is that many wireless transmitters use their own wiring conventions. Lectrosonics uses a five-pin connector (a TA5), while Sony and Sennheiser use a 3.5mm jack… and the two aren’t interchangeable. So while I have a fairly diverse collection of lavs, they aren’t all wired to use the same transmitter. One of these days, I’ll get rid of my other transmitters and go “all Lectro,” but that’s a somewhat expensive proposition.

Two Sennheiser lavs

My lav mic locker includes the following:

  • Countryman EMW (wired for Lectrosonics)
  • Countryman B6 (Lectro)
  • Audio Technica 899 (Lectro)
  • Lectrosonics 119
  • Lectrosonics 152
  • Sennheiser ME102
  • Sennheiser ME104
  • Sony ECM44B (hardwire)
  • Sony ECM55B (hardwire)
  • Sony UWP lav
  • EV CO90 (hardwire)
  • EV MysteryLav- looks suspiciously like a Sanken COS11

These two mics are the ones I use most often... a Countryman EMW and my current favorite, the Audio Technica 899

There is a really good article about comparing several different models of lav mics at Ken Stone’s website- click here. I haven’t done extensive side-by-side comparisons of all the mics that I have, but I’ve got some favorites. I found a good deal on some Countryman EMWs. These are small, rectangular, side-address lavs, similar to Trams, which are kind of an industry standard. But Trams were too expensive and only available new. The EMWs small size and resistance to handling noise are big advantages and I used these for several years. But then I happened to try an Audio Technica 899 during a 3-person shoot… two people wore EMWs, and one wore an 899. While all sounded good, I was surprised at the reduction in room noise when I soloed the 899… there was a significant improvement in the amount of background noise. Since then I’ve managed to purchase a set of three 899s, and these are my favorite mics in most situations.

Any mic with a larger head is generally not my first choice on the set, since most clients would rather hide the mic in the talent’s clothing, even though this means a reduction is sound quality. My Sony 55b almost never gets used for this reason, even though it’s an excellent-sounding mic. My Lectrosonics mics have some rather questionable-looking cables, so I keep them to use as backup mics.

The Sony PCM-m10 vs Zoom H4n

Like many folks, I’ve been using a Zoom H4n

Zoom H4n portable flash recorder

as my bag recorder for awhile now. But I recently acquired a Sony PCM-m10. This post will compare the two for use as a location audio-for-video recorder. My recorder of choice is an Edirol R4Pro, but it’s too large to use in a bag along with a mixer. What we’re after here are small, palm-sized 2-track recorders, and there are several to choose from.

My Sony PCM-m10. The front panel layout is fairly straightforward.

The Zoom is a good recorder, and has a number of useful features that aren’t available on many other recorders. These are easily discovered through any web search, but the major points are 4-track recording ability, and XLR inputs. But like everything in life, there are drawbacks… at least in my application. These are:

Lousy battery life– There’s no getting around it, the H4n is a power hog. Used as a straight recorder, I get about four hours from a pair of AA alkaline batteries. I’ve been on shoots where I’ve drained two sets in a single day, and the stress of starting a take with a low battery  indicator has to be experienced to be fully appreciated. Or worse still, putting in your last pair when you’re a mile and a half in the woods… and your extras are back in the car. My workaround has been to use very expensive lithium batteries, which will last nearly three shooting days. The folks at Zoom realized their design was a bit thirsty, and they put in a “stamina mode” switch on the back.

Beldar Conehead... never a big fan of reduced sample rates...

This will extend the battery life by disabling some features, but it limits your sample rate to 44.1/16 bit. As Beldar Conehead would say, “Mips!!! Unacceptable!!!” If you’re too young to understand the reference, I’m sorry, but your cultural education needs some work. Do the research.

The Zoom H4n is bigger overall, and the larger input connectors makes a slightly cumbersome package in a bag.

Picky Line Inputs– the 1/4″ inputs on this unit are high impedance ins. These are great if you want to plug an electric guitar directly into the unit, but for a mixer tape out… not so much. I know, you can buy a cable with a built-in pad, but it’s still a pain in the butt.

Fragile Form Factor- the adjustable mics on the top of the unit are nice for grabbing a quick stereo soundfile, but when used in the bag they tend to be somewhat vulnerable. The big 1/4″ connectors means it usually lives in the bag mics-down, and I worry that these may someday break.

4-Track Limitations- While the zoom H4n is widely advertised as a 4-track recorder, the implementation isn’t as great as it could be. Yes, it can record four tracks at once, but two of those tracks are intended to come from the unit’s onboard mics. There is a 3.5mm jack that can bypass those mics, but this is still a bias-powered mic level input. It can be made to work with yet another padded cable, but doing so involves such a web of special cables and workarounds that I’ve never tried to do a 4-track recording in the field.

The Sony is thinner than the Zoom, but this is a limitation of the XLR connectors.

These drawbacks led me to search for a better solution for recording in the bag, so I’ve gotten a Sony PCM-m10. For my application, the Sony is a better choice, because:

Line Inputs– At first glance, the 3.5mm stereo line in jack would seem to be a downgrade of the balanced ins on the Zoom, but since these are true line-level ins, this isn’t the case. Levels match fine from my mixer tape out using a plain 3.5mm stereo cable. Plus the Sony has a rotary input level control, so adjusting levels is a bit faster that setting a level using an up/down button, as it is on the Zoom. It is slightly more likely to accidental adjustment through careless handling, though.

Battery Life– Power management is vastly improved over the Zoom. The manual says to expect around 4o hours from a set of batteries… less if you use higher data rates. I record at 48k/24bit, and I can get more than three full days of work from a single set of alkaline AAs. The stress relief alone is a big value for me, as I’m not having to constantly check my battery level.

Compact Case- While I’d think these are about the same in terms of their fragility- both are basically built with plastic cases and could be damaged from extreme handling- the Sony is smaller and rectangular. The Zoom is slightly larger, but the bigger 1/4″ jacks can place more leverage on the connector itself, plus the irregular shape makes me think that of the two, the Zoom is going to be more likely to break over time. (I do plan to make a mic guard for the Zoom that screws into its tripod mount, but haven’t managed to find time for that experiment yet.)

The Zoom usses buttons to set the record level, while the Sony uses a thumbwheel. This isn't a digital encoder, either, but an analog level control.

Better Filenames- Though this seems a little nitpicky, I do like the filenaming convention on the Sony better than the Zoom. The Zoom gives each recording’s filename in a given folder a sequential number, starting at 001. The Sony does the same thing, but it adds the date at the head of each filename. This way it’s a little easier for me to tell what’s in each file without having to open it up and listen to it… handy if I’ve been shooting for four days and neglected to download. It just adds a little confidence.

There was one situation where I was glad I had the Zoom. I needed a lav mic on a motorcycle, and  expected the talent to drive out of wireless range. Using the Zoom, I plugged in a hardwire mic directly to the H4n’s input, started the recorder, and put the whole package in the bike’s saddlebags. You couldn’t do this with the Sony… at least not with a hardwire mic. I did some experiments by plugging in various mics with 3.5mm jacks into the Sony’s input, and  it turns out that mics wired for Sony’s UWP transmitters will work fine plugged directly into the input jack… a neat trick in a smaller package. Not so with mics wired for the Sennheiser G3 series, though.

While both are fine recorders, I think overall I prefer the Sony. In fact, I’ve ordered a second one. The idea is to use a pair to record iso tracks from my wireless units, then sync them after the fact using Plural Eyes software. I’m still running tests to figure out the best way to pull this off… the results will be in another post.

To be fair, I haven’t tried some of the other palm recorders available from Edirol, Fostex, Tascam, Marantz, Roland, and others. These two recorders are the ones that I own. (I’ve no connection with either company, nor have gotten any freebees or discounts from anybody. I’d be happy to take some, though.)

A Nine-Volt Power Solution

Thankfully I’ve been doing a lot of work lately. And as a result, I’ve been going through a lot of 9v batteries. My Lectrosonics wireless units are quite good in terms of their battery life… I can get about six hours from a Duracell Procell alkaline battery. But running three units all day long, plus a pair for my Shure FP33 means that it’s tough to keep enough batteries on hand. I always like to have a spare unopened case with me, just in case… running out of batteries during a shoot is just not an option.

The iPowerUS Lithium-polymer 9v batteries and charger

Unfortunately, most rechargables do not have enough energy density to be very useful on the set. I’ve tried some 9v NiMH, and they would only last 2 hours in the same application.

There is another option that is available from Trew and other dealers. A company called iPowerUS makes a 520 mAh 9v Lithium-Polymer battery. I had heard about these before, but a DP I worked with recently (Roger Herr, shooting Infested for Animal Planet/Darlow Smithson UK) actually had a set and recommended them, so I finally broke down and invested in a set.

I’m pleased to report that these are working great for me. I can get nearly an entire day in my wireless units from a single charge… even a little more by switching the power off between takes, so I’m not constantly changing batteries. iPower says their batteries will get over 200 charge cycles from each battery, and Trew reports this to be accurate… and in some cases, 200 cycles is a conservative estimate.

The downside is the initial cost… these batteries are initially quite expensive at $23 each in sets of four. (About $30 each with a charger.) But if we do a little math, they are really dirt cheap:

iPower- appx $30 each/200 charges = 30/200 = .15 per use
Procells- appx $20/12 (case)= 1.66 per use

These batteries break even after you’ve used six cases of 9-volts. (Or if you prefer, after being recharged about eleven times.) For me, that’s around 9 or 10 shooting days. These make sense if all you consider is dollars and cents. But more than that, it saves me time and grief not having to order a couple of cases of batteries every time I turn around. They charge in about 45 minutes, and the iPower charger comes with a 12-volt option for car charging… really handy. About the only downside I can think of is they don’t have a AA-sized solution for my Sound Devices gear.

So while it was a momentary pain in the wallet at purchase time, I’m really glad I bit the bullet and bought these batteries. So far, they’re quick, dependable, work great, and save quite a bit of cash and hassle over time.


A New Bag Upgrade

I just completed a job in Nashville, and I did some shopping at Trew Audio. One of the things I was interested in was a long-overdue bag upgrade. This time I went with a Petrol bag… a small Deca Eargonizer. My friend John Billings (location sound, studio engineer and session musician in Nashville) bought one recently and likes his, so I brought one home.

The Petrol small Eargonizer bag

The Petrol small Eargonizer bag

There are a number of things that I like about this bag, one of them is space. It’s a bit roomier than my old bag, which means it’s naturally a bit bulkier than before, but not by much. It’s “stiffer” as well, meaning that it’s made with semi-rigid sides. This means more protection for my mixer (though I never felt my gear was vulnerable with my old case). It also allows more flexibility with the configuration. Petrol includes little risers to lift gear up, which works because of the rigid sides.

Actually, Petrol includes a lot of little options and extras. Some will be indispensable for some folks, some will be unneeded for others… but it means I can configure the bag the way I want it, which is a big plus. One item that everyone will like is their wireless pouch… my bag came with a pair, and there are anchor points for two more, which I’ll be ordering directly.

Petrol bags come with a number of risers, dividers, and pockets for custom tailoring the bag to suit various ways of working

Other details that are really handy:

  • Multiple anchor points for the strap, so the bag can be balanced
  • the clear vinyl window flap attaches with velcro on both sides, so it can be removed and stowed out of the way in clear weather.
  • Places to put sharpies and pens (though it doesn’t have a dedicated business card pocket, and I always like to have cards ready to hand out).
  • Cutouts on the inner divider for easier & neater cable routing.

Just to be fair, there are a few small details that I’d personally like to improve. I’d like some more padding on the strap, since I usually run a fairly heavy bag. And some method of attaching transmitters for Comteks or camera hops on the strap, up high and away from the mic receivers, would be cool. But my biggest irritation are connector covers. For some reason most bag manufacturers don’t make them removable, and they are always getting in my way when I need to make fast connection changes in the mixer. I never take my personal gear out in bad weather, since I can’t afford to replace it if it gets damaged, so the connector covers aren’t quite as big an issue as it is with, say, a news crew. At least Petrol makes their covers out of a lighter, more flexible material, but I’d like something that could either be removed or rolled completely out of the way.

The bag from the front. Its center divider can be removed if need be.

This isn’t to say that I don’t still like my Portabrace bag… for me, the Portabrace is better for my old Shure FP33, since its smaller & lighter. That’s my rig of choice when I need to be very mobile. (Portabrace doesn’t list the FP33 anymore on their website, but there should still be plenty of bags for them around.)

Overall, though, I think the Petrol is a great bag and I expect to get many years of work out of it. By listing my old bag (that wasn’t really that old at all) with Trew’s consignment program, the net cost of my upgrade was pretty small… a successful trip, I think.

Be Careful What You Ask For…

I received a call from Atlantic Television in NYC awhile back… nothing unusual, they were doing some advance work for a company in London, could I do the sound. I was free for most of their schedule, so sure, I’d be glad to help out. They told me this would be for National Geographic, but that it would be a small crew shooting a reality-style show. Nothing unusual there… but then things started happening to indicate this wouldn’t be the usual shoot. One of my students was hired as a location scout, and she was looking to build a set in a commercial space, and the number of shooting days started to climb… a lot…

I was skeptical that it would happen at all, but thanks to a number of fortunate events, the shoot was scheduled for Chattanooga (originally was going to be in Knoxville) and I was contracted to be the location mixer for not just a single show, but an entire series. I can’t disclose much… we’re shooting under a working title, which may yet change. But there will be eight initial episodes.

For our little production community here in Chattanooga, this is HUGE. We’ve never had this kind of opportunity here before, so for much of the crew, it’s a large block of work. Just speaking for myself, in three weeks I’ve already surpassed the number of shooting days for all of last year. I’m a little pooped, but any day that I can go to work is a good day.

My work area on the set. I've brought out nearly all of my gear for this shoot, and having the resources available has been handy.

And thanks to some less-than-satisfactory work by freelancers in other towns, I’ve been cleared to work on out-of-town shoots with the crew as well… their policy is to use local talent whenever possible to save money, but I’ve been given an opportunity for more work. It reinforces the idea that, as a soundperson, it’s important to be on your toes and make the extra effort whenever you can. The concept of “added value” applies well here. I do all I can to make myself as invaluable as possible on (and off) the set. Getting good, clean sound is, of course critical, but there’s always more that can be done on the set. Dressing cables, keeping detailed sound reports, making sure the talent has water, helping load, carrying cameras, helping change lenses… even sending emails suggesting good spots to eat around town… it’s all important and has helped me secure  some additional dates.

And there’s more to come. While most of the studio crew takes a break tomorrow, I’m heading out of town in the morning to shoot at Cirq in Atlanta, then the next day in Collegedale, then back in Chatt, then a date in Knoxville next week, with two more possible dates in between.

My cart rolled onto the set for taping. I'm using my Sound Devices 442 mixer paired with my Edirol R4Pro, which is serving as the master timecode source for two Sony F900 cameras. Here I'm set up for a wireless camera link, but we went to hardwires after the first day. The wireless worked fine, but since the cameras are connected via coax to the monitor cart, there wasn't any advantage

Frontline’s Football High

Here’s a digital postcard for Frontline’s Football High. I worked on  a segment of this show a few months ago… it airs April 12th. Produced by Ark Media in NYC for WGBH Boston and PBS. Field Producer Caitlin McNally, DP Sam Russell. The links in the image below are inactive, but you can watch a preview here.

Harrison Mixbus Print-Friendly Documentation

As I’ve mentioned before, I’m a big Mixbus fan. I don’t get many music mixing jobs, but when I do, I prefer to mix them on Mixbus, since it’s the closest thing to working in my old analog studio (On Line Audio in Charleston, SC) that I can afford. For me, it’s easier, sounds better, and is more fun than fooling with Protools.

Harrison's Mixbus on OSX

But one of Mixbus’ downsides is that since it comes from the relatively small (though famous) console maker Harrison, there isn’t a huge marketing staff that can create a comprehensive print manual. There is an online manual for Ardour, the open-source engine on which Mixbus is based. It’s helpful, but it’s a PDF… which means to use it, you’ve got to have it up on a computer, and switching windows between Mixbus and Acrobat is a bit of a pain. I prefer a real book, open on my lap, with the computer running the program I’m trying to figure out.

After printing out the first few pages of the PDF, I learned this wouldn’t do at all… the document is loaded with full-page screenshots, and the on-screen formatting wastes reams of paper and gallons of ink. So, just for my own use, I re-formatted the document to be more printer-friendly by reducing the type size, adjusting the layout, and cropping and/or shrinking the screenshots down.

Then, just for grins, I added some Mixbus-specific sections and comments for those of us who are using the commercial version of Ardour (Mixbus) rather than the free open-source program (Ardour). The mix windows are very different between the two. Most of this information isn’t new… I rewrote it using the Mixbus quickstart document. And there are still plenty of things I’d like to do with the program that aren’t explained. (#1 on my list is how to print a track with only the output of a plugin… there’s gotta be a way, and it’s probably simple… but it isn’t obvious, at least not to my sucking-in-the-seventies brain.

I figured this might be helpful to other Mixbus users as well, so I’m making this document available free to Mixbus owners. Just send me an email to BGilbertSound at gmail dot com. Include your mixbus serial number. I’ll email you a copy of the PDF. Let me know if you have comments that need to be added, and hopefully the document will grow into a real manual.

Location Sound Class at Chattanooga State

My location sound class at Chattanooga State Community College has been given the green light, and I’m very much looking forward to it. Dave Porfiri has been working with Chatt State for some time now, developing a film and television technology program to grow the crew base in Chattanooga, and this course is part of that program. It will be a six-week practicum on the practical aspects of  location sound, concentrating on things like booming & lav placement… just the basics.

It won’t be the first time I’ve taught a class… I was Instructor Of Record while attending graduate school at the University of South Carolina. That was a long time ago, but the basic concepts remain the same. This course will be different since it concentrates on location sound for film and video, and it’ll be the first that I’ll do all the instructional design. We’ll see how it goes.

More Fun With 5.1… The Double Mid-Side Technique

After my last post on an inexpensive 5.1 workflow, a reader (Peter Tooke… thanks, Peter) advised me to look into the double mid-side technique. This is a method used for 5.1 surround sound recording that I’ve seen used on feature films, and while it can be a little complex to wrap your head around, it’s pretty neat.

The “mid-side” mic technique is a method of recording stereo using a cardioid mic facing forward (the “mid” mic) and a bidirectional, or “figure-8″ mic facing left and right (the”side” mic). These mics require a little processing at the mixer, though, before we get a stereo signal.

Schoeps has several hardware options to support a double mid-side setup

The mid mic is panned to the center, but the side mic is split into two equal signals. You can do this analog using a transformer-balanced splitter, or digitally by copying the input to duplicate channel. Pan one of these mid signals hard left, and pan the other hard right, but… and this is the key… invert the phase on the right channel.

The beauty of the mid-side technique is that if the left and right channels get summed together for a mono signal, you get no phase cancellation between the two signals. We used this technique in the early days of television, when some of the sets were mono and some were stereo. Using mid-side stereo, both stereo and mono televisions sounded fine. (More details about the mid-side technique are here.)

The double mid-side technique is an expansion of the mid-side technique. By simply adding a rear-facing mic we now have a system that can generate five channels of audio using only three tracks. Use a shotgun for the main mid mic, add a bidirectional mic for the side signal, and a cardioid rear-facing mic. The side signal is shared between the front and the rear mics. Each mic is recorded on its own track.

Decoding the three signals into a 5.1 mix is straightforward. The shotgun becomes our center channel, shotgun plus the mid (split, panned left and right, and phase-reversed for the right side)  becomes our left and right front signal,  rear cardioid plus the mid (split, panned left and right, and phase-reversed for the right side)  becomes our left and right rear signal… pretty neat, eh? And like the standard M-S stereo technique, the signals can be summed to mono without phase error.

The Schoeps double mid-side recording solution has the advantage of the entire rig being able to fit inside a zeppelin.

Shoeps has a good bit of information about double mid-side technique on their website, including some elegant hardware solutions for implementing this system in the field. Hang on to your wallet, though, cause this ain’t a Chinese knockoff… it’s some serious hardware that is priced accordingly.

Schoeps even has a free double mid-side plugin that decodes the three signals for a double mid-side system. Order it here.

A screenshot from the free Schoeps double mid-side plugin