Audio For Picture: Mics, Mic Placement, Wireless and Recorders

In the last post, I discussed things to consider when choosing your locations.  More or less, my advice was to do some audio tests in the space you're going to shoot in before you commit to shooting there.  If the client is pushing you to shoot in a space that looks great, but doesn't sound great, be sure to set their expectations correctly in terms of what it will actually sound like at the end.  Make them aware that while you may be able to do some work on the audio or perhaps hire an audio mixer, both for an added fee, not everything can just be 'fixed in the mix'.  

For this post, I'm going to help you make some mic choices, wireless mic options and discuss some recorder options.

I'm going to spend a little time talking about technical things, but I hope to not do it in a mind-numbing way.  Those that want those technical details will have to look elsewhere and for some of this, you'll just have to trust me.

Let talk about mics.

Most often, when audio is recorded on set and delivered to me in a mix, I see a lavalier mic track and shotgun mic track for each subject, especially when they're alone on camera.  This is pretty standard, but it isn't always the case.  Sometimes both are recorded, but the better sounding of the two is what ends up in the files (AAF or OMF, more on those another time) for me to mix.  I like getting both delivered to me very much and here are the ups and downs for each. 

With lav mics, I get a more present sound - one that's generally a little closer to the speaker's mouth and therefore, the room and background noises are minimized more so than with a shotgun mic.  That said, a good, well placed shotgun mic often sounds better as the mics are (generally speaking) of higher quality and have a much larger diaphragm, which can help in this case.  Without a doubt, shotguns will pick up more of the room and background sounds, but sometimes, that can actually help.

"Well placed", what does that mean? Lavs come in a variety of pick up patterns, with omnis being the most popular on production sets.  For live sound, I see more cardioids and tighter patterns than omnis.  You more or less want to get the mic either dead-center on a tie in about the middle of the subjects breastbone or on their lapel (hence the name, "lapel mic").  Move the mic too high and the high frequencies literally get cut off by their chin and moving it too low means you're more than likely going to hear more room and clothing than their voices (decreasing the signal to noise ratio).  An omni mic is wonderful because it doesn't suffer from proximity effect like a pattern mic will.   Sometimes, I like using proximity effect, but not often in this case.  Either way, feel free to pin up an omni upside down to minimize plosives from the speakers nose and mouth.  Plosives are when a burst of air hits the mic capsule and you hear what sounds like a "boom".  Putting the mic upside down keeps the open area of the capsule pointed away and won't change the sound much - an omni mic is picks up sound from all sides fairly equally.

A couple of big pitfalls you can run with a lav mics are pretty obvious.  You hear their voices a little better than a shotgun, but you also hear their clothing - esp if they're moving around a lot simply due to the mic being attached to the person.  Another is the look of the lav.  Some people don't like seeing the mic as it takes away from the piece - you're watching a video rather than having an experience.  Some lav mics come with clips and other tools that can help you hide them, but more often than not, these don't work out so well.  Some, like my favorite, the Sanken COS11 lav, come with a very useful set of tools that actually do work. It's important to note that if you do choose to hide the lavs, you really have to pay even closer attention to the sound.  If it sounds dark and muddy, that's not good.  Compare it to the subject wearing it on the outside by trying the outside first, record a little, then move the mic to where you can't see it and press record again.  Have them answer the same question twice, roughly the same way and then listen back.  If it's significantly different, it may not work out in your mix.

I talked in the previous post about having someone actually monitor the audio, just as you monitor the video while you're shooting.  More on this later, but for now, you're going to want someone who is PICKY AS HELL about this do the listening.  If the suit jacket moves against the mic, right on their words, you're in big trouble if you want to use that line.  Ask them to say it again.  More on that later.

With a shotgun mic, you don't see it in the shot (if you're careful) and you get a sound that puts the viewer in the room. You get a sense of the space when you watch the piece by the sound of it.   This is something that can't be overlooked and can contribute a whole lot to delivering an experience, not a video.  More often than not, lavs just don't help you in this regard. 

Again, a well placed lav is sometimes really critical to keeping the sound of the room and background noise to a minimum.  They can also be the only option if you plan to shoot from a distance with a wide shot that makes booming impossible.

There is far more territory to cover there.  I could go on and on about lavs vs. shotguns and pitfalls.  I'm going to move on for now.  Feel free to send questions along if you'd like more info.

My favorite lavalieres on set or otherwise are without a doubt the Sanken COS11 mics.  They're amazing.  Nothing else I've heard even come close, but I haven't heard everything out there.  

For shotguns, I've heard a few over the years that I really, really like.  The first is an old standby that never lets me down - the Sennheiser 416, which is killer sounding mic.  Always puts a smile on my face when I hear one and I can pick those out easily in a mix.  The next one is the Schoeps CMIT-5U.  Incredible mic for not a lot of money.  I love these mics equally.  I've heard that DPA shotguns are also amazing, but I haven't used one yet. 

If you need to use a boom, choose one without a cable in the middle!!  I'll never understand how someone uses one with a cable in it.  The cable inevitably makes noises as you move it and it's connected to your microphone.  Instant noise generation is guaranteed and no, the isolation device you rented won't help you there.  Use a straight XLR cable, outside the boom and get ready for a day of keeping your hands over your head.  If you have the option to rent a c-stand clamp for your boom pole, do it. 

The next thing to cover is how you get the signal from the mic into your recording device.  

When possible, always use a wire.  There is no reason whatsoever to use wireless in a sit down interview unless you plan on going very fast and moving from location to location.  Even so, you should have time to add an XLR cable to the end of the lav or shotgun mic.  If you're booming, a plug on transmitter can be very helpful, but can also introduce levels of complexity that most don't consider.  One is that the mic pre in that case is IN the transmitter.  You can't easily tweak it while recording when it's out over the subject's head.  The other is that it adds weight and size, both of which you might regret on long shooting days with ceiling heights that are not helping you.

So, let's talk about wired vs. wireless .  With a wired mic, it's pretty easy to guess what you're going to get.  I like Canare Star-Quad cable for on set, production audio capture.  It's reasonably good sounding and does a fantastic job of eliminating RF from the signal that can come from power and signal cables that are often everywhere on a set.  That's the goal of an XLR cable in the first place - to eliminate RF from penetrating the long antenna you just put down on the floor.  

Once the signal is getting to your recording devices, you're pretty much there.  It's of course critically important that you print good levels and listen to what you're recording, but we'll get into more of that soon.

With wireless mics, you have several layers of potential problems layered into the chain.  The very first is the quality of the wireless system that you've carried to the set.  The most popular ones I see are the Sennheiser Evolution "G" series.  They have small, portable transmitters and receivers and you can get a system with a lav mic for roughly $650.  I can hear these units almost immediately when I open a session that was recorded with one and that's not a good thing.  

Sorry to pan these so hard, but I can't stand the sound of inexpensive wireless systems and you should do your best to avoid using them.  If you can't afford one of these, rent better ones until you can.  Seriously, the sound of mics on cheap wireless systems has the life choked out of them and I'm not kidding.   If you can't hear it, you'll have to trust me, it's awful and it definitely impacts your the final product.  There are circumstances where I understand why you had to use something of this sort, but the rampant use of them on productions that have the budget to use a real wireless system is just plain nuts to me.  If you have to use something inexpensive, consider the Shure FP series as an alternative to the Senny's.  You'll spend about the same and you'll be happier and so will I if I end up mixing your piece.

For me, I think portable systems begin with units like the Lectrosonics 100 series.  The lav mics these ship with should be used as back ups only, but the wireless systems are not a little better than G series mentioned above, they're miles and miles better.  They're roughly twice the cost though depending on which one you chose and again, that lav that ships with those systems shouldn't taken seriously, so you'll need to buy a lav as well.  

Another new system that I've used a lot recently is the Shure UR5 receiver with UR1 bodypack transmitter.  When used properly, these units sound like a wire with incredible clarity, punch and they're dead quiet to boot.  The tiny glass screens can be a bit scary for portable use, but the easy to navigate menus, the frequency scanning (to search for an open channel) and infrared syncing to the bodypack make this combo a winner.  Something like this would set you back about $2k.  Again, not cheap, but it sounds like a cable.  The Shure lav mics I've used are best for live sound and are not my favorites.  A bonus with buying a Shure wireless system is that everyone makes and adapter for their transmitters - Shure is the largest manufacturer of mic and wireless mic systems in the world by a long shot.  They sell more 57's and 58's than nearly every other companies products combined.

Lectrosonics also makes some high end systems if you're looking into getting something in the price range of the UR5 system.  These are the most commonly used portable wireless systems used by pro's.  They're extremely durable and they sound fantastic.  I kind of like the Shure's better, but you won't see nearly as many of those in the field and you would be able to rent comparable Lectro systems at most broadcast houses - something you may want to consider for back ups or to add more channels.  They'll play well together.  The Lectro's are tougher to use for the most part, but they can be thrown down a flight of stairs (something I don't recommend doing on purpose) and they'll keep transmitting. 

If you do use wireless systems, It's always important to know what frequencies are a good starting place.  You can always ask your local broadcast rental house for advice.  In fact, I highly recommend that as they'll know what you'll be up against.  Digital television is your first big concern when using UHF mics and you can easily search for this info online.  In the very first search I did, I found that Shure has an online search tool here that can be helpful for using their systems.  I'm sure with more digging, you can find more resources.

I'm going to move on to recording units and levels for a moment and circle back to wireless in a few. 

Some cameras have built-in XLR inputs and for a number of reasons, this often a good choice to go with.  The big one is syncing things up later and often be difficult if you use an external recorder.  That said, you'd have to monitor the sound off the camera and most of the time, both the mic pre's and headphone jacks are pretty cheap in cameras - they're far more concerned about making great optics, sensors and viewfinders.  If you have an experienced audio guy with you, he'll often carry his own mics, boom, wireless and a mixer that all fit into a bag he can carry around on set.  For bigger productions, guys use "audio carts", but let's stick with the 4 mics or less plan and an audio guy (or not) for now.

Modern portable mixers, such as units made by Sound Devices, have the ability to listen back to what's being printed on the camera (and see the meters, provided they took the time to set it up properly) through the use of a break away cable that includes a return from the camera's headphone jack.  These modern, portable mixers have a special input that allows a user to toggle over to that return from the camera and see the level and hear the signal from that headphone jack.  This can be a lifesaver and really is the only way to go.

What these mixers also have are fantastic sounding mic pre's and they're dead quiet.  I was fortunate enough to demo one of the very first production units made by Sound Devices when I worked in a broadcast equipment sales and rentals house, roughly 15 years ago and was blown away by the construction and sound quality of this little, one-channel, portable mixer.  They've come a long way since then and offer multitrack recording right in the mixers themselves and more.  There are many reasons why the pro's reach for these and these are just a few.  

As I started to allude to, another option is to have the audio person carry a portable recorder and use the on-camera mic as a reference to sync to later.  You may be able to sync between the recorder and camera on set and there are tools that automate a manual sync in NLE's, but be sure you know what you're doing by testing it all out before you attempt this.  The last thing you want to be doing is syncing it all up by hand later.  I know one thing, I won't be doing it for you.  :)

If you use an external recorder, one of the popular ones I can hear right away are the Zoom H4 recorders.  I won't even post a link to this thing because again, I can hear it because of the absolutely horrible quality.  These recorders are by far the most popular ones used on shoots I end up mixing the audio for and I can't stand the sound of them.  Sorry, they stink on every level - the pre's are bad, the converters are bad and the clocking is the worst I've ever seen, which leads to things falling out of sync.  

The Tascam line of recorders are a far better choice in my opinion.  The units are budget conscience without being cheap and they offer a bunch of models.  Today, I wouldn't but something that doesn't have XLR inputs and 24 bit recording.  The built in mics can be handy for the listening tests I talked about in the previous post, but are not essential.  From there, you could look into the Zoom H6, which I've been told is a much-improved unit, but if I've mixed something recorded on it, I'm unaware.  I like asking, but I often only ask when I hear problems and when I have asked, it's usually an H4 - which is how I know what they sound like.  

The Sound Devices recorders are once again my clear choice.  I can always tell when one was used - they sound stellar.  For many, these are a rental option only, but I can't say enough good things about them.

So much to go into there, but for now, I'll go into recording levels.  

When I'm recording people talking, I like to print the level high enough to get over the noise floor of the set up, but leave a lot of room for when people get excited and laugh or shout.  I find printing with peaks no louder than -12dB can work really well.  You're above the noise floor and leaving a good amount of room for "overs" - clipping and distortion.  Go ahead and ask the talent to clap their hands and see what happens.  If you go into the red, back down the level a bit and try again.  Some like printing audio around -18dB or even lower. 

If the unit has a limiter, try it and see what happens.  Make sure it's one that doesn't add any compression other than for peak limiting.  If you find yourself leaning on that limiter, you're probably recording too loudly.

One thing I want to be sure to mention is that it's SUPER HELPFUL to get a minute of room tone for each location and for those files to be clearly marked and organized into a folder that gets zipped up along with the OMF/AAF.  Also, if you hear a distracting sound when someone is being interviewed that's momentary, but is definitely there (and perhaps right on their words), ask them to immediately repeat their answer.  Most people can do this on command with very little coaching.  They're in such a self-aware state, they can often hear their words clearly as they're saying them and they'll parrot them right back if asked.

And yes, someone has to be watching the levels and actually listening to the audio being recorded at all times.  Did I say that enough times?  Well either way, you're going to see that over and over here.

Back to wireless for a second to wrap things up…

Something to consider with wireless mics is that the preamp for the mic, is in the transmitter.  It has to be, right?  How else would phantom power be delivered to the capsule?  

With that in mind, you have to get the level of the mic set correctly within the transmitter prior to sending over radio waves.  What's the right level?  This isn't much different than setting the level of the recorder.  You want to get above the noise floor of the transmission, but not too loud that it distorts.  I personally like to hit the transmitters pretty hard with level.  If you don't do this, you may hear mild to severe amounts of white noise "wash" on the subject's voice.  I just went through this with a mix recently and it was impossible to remove all of it. I ended up having to duck a lot of high end to minimize the noise, something I wouldn't have done as a choice for the piece I was mixing. 

Enough for now.  Send along your questions and comments and follow me on twitter for updates to the blog which will be coming soon.   Also be sure to check out the Go Creative Show, which I mix every week.