Better Recordings of Sermons

30 08 2007

I’ve been thinking about the recording of messages lately. I’ve been asked about it a few times in the last few months. The question usually goes something like this, “We want to record our pastor’s sermon, should we go straight to a CD recorder, or into a computer then burn a CD?” If you have read this blog for any length of time, you’re probably thinking my answer is, “It depends.” But you’d be wrong. In this case, I always like to go to a computer for recording. The reason is simple: When you record straight to a CD, what you record is what you get. If you start to early, you have a bunch of dead time up front. Stop to late, same thing at the end. If your level was too low, the CD will be too quiet. Too loud…well, even the computer won’t save you there.

So I’m going to tell you what I do here at Crosswinds. This is not necessarily the definitive way of recording a message. But it works really well for us. We have dual destinations for the recording, CD duplication and the web. My goal for the finished product is a message that is easy to listen to, without a lot of intervention (ie. adjusting the volume up and down) on the part of the user. I consider the environment and equipment people will use to listen to the message–it will be either their car or at the computer. Not exactly the greatest places to discern maximum quality. That’s why I go for listenable. Yeah, I know that’s not a word, but work with me here, OK?

Signal routing wise, we take the direct out of the preacher’s microphone and run it into a compressor. You should know that the pastor’s channel is already insert compressed, albeit pretty mildly, to even out the volume in the room. Yes, I know this is double compression and I could eliminate it if I double bussed the channel. For what we’re doing it’s not worth it. From the compressor, we run into a 3rd party sound card (way, way better than on-board audio). You could also use a USB or FireWire audio interface. While recording, we take care to keep the peaks at about -12 dB to ensure we don’t run out of bits and distort the signal. Finally once the message is recorded, I apply some additional dynamics control to it. Yup, that’s right a third pass of compression.

At this point, audio purists are tearing their robes, putting ashes on their heads and crying, “Oh, the humanity!” I don’t care. I want a CD that I can put into my somewhat loud truck’s in-dash and listen to it while driving down the road without turning the volume up every time the pastor gets quiet.

I thought some visual aids might be helpful to explain some of what we do. The following example was taken from another churches website to demonstrate via waveforms what we’re doing. I’m guessing the recording was not compressed in any way prior to being recorded. In my setup, we already have a mild 2:1 comp, plus a little more aggressive 3.5:1 before we get to the recording. But this shows what you can do “in post” when you record to a computer (or if you’re just a purist and want to jump through whatever hoops you need to to only compress once–knock yourself out).

Let me issue a disclaimer here: I am going to discuss ratios of Loud to Quiet in a minute. I determined the ratios based on pixel counts of the waveforms. I know they’re not accurate dB ratios and do not represent true loudness levels. But for the purposes of illustration, work with me here. We’re going for concept, not 100% theoretical accuracy.

Let’s look at the original waveform, as recorded.

The Initial Waveform

As you can see, there is a pretty wide dynamic range to this recording. The red bar represents the volume of the loud parts; the yellow, the soft. It was also recorded pretty low, so I really had to crank it up to hear it. What we’re seeing is that the loudest parts of this passage are roughly 13 times louder than the quiet parts (refer to above disclaimer…). In practice, that burst at the beginning (on the left) was really loud, but by the time we got to the right, I was having trouble hearing it over the noise of the fan in my room. I had to keep turning it up.

So let’s see what happens if we were to apply a compressor filter to this in our favorite audio editing program (for this example I used Audacity, which is really cool, really powerful and really free). To start, I tried a compressor with the threshold set at -30 dB and a 3:1 ratio. This is how it looked afterward.

-30 dB, 3:1 Ratio

1 Compressor Was Applied

Look at the difference. Now our Loud to Soft ratio is somewhere around 5.5:1 (again, see above disclaimer…). What this means is that there is significantly less difference between the softest passages and the loudest ones. The overall level is pretty low however, so we’ll apply a normalizing filter to it. After we do that, it looks like this:

Normalizer Dialog

I will typically normalize to -1 dB, just to give it a little buffer (which, by the way, is why I didn’t normalize to 0 dB in the compressor dialog). The normalization process takes a look at the signal and applies gain to the entire recording until the highest peaks touch the level you specify (the maximum amplitude). We do this at this point because we know what our highest peaks are (unlike when we are recording live), and we may as well take advantage of all the headroom the system has available.

1 Compressor, normalized

That looks better, but when I played it back, there was still a little more dynamic range than I wanted. So I got a little more aggressive with the compressor. This is how it looks with the threshold set at -35 dB and a 4:1 ratio

-35 dB, 4:1

1 Compressor is applied

Ok, now we’re getting somewhere. What we are doing here is taking the loudest parts of the message and bringing them down closer to the softer parts. In this case we’re down to just over a 3.5:1 ratio between the loud and soft. Again, we’ll hit it with a normalizing filter and it looks like this:

1 with a normalzier

Now that’s what I’m talking about! That will be super easy to listen to, and believe it or not, there’s still plenty of dynamic range in the recording to easily tell when the speaker is emphasizing his words and when he’s pulling back and speaking softly. The implied dynamics are there, but now I can actually hear what he’s saying.

If this was recorded at the proper level (-12 dB peaks), a -35 dB threshold would have been way too low, and would likely have sucked the life out of the recording. You don’t want all the peaks at exactly the same level, because that just sounds weird. You will have to experiment with this to determine what sounds good for your system.

What is the lesson here? Whether you want to compress the recording on the way to the computer is up to you (though I think every speaking mic should be insert compressed for better performance live anyway), but the above examples give you a good idea of what you can do to maximize the listening pleasure of the audience after the fact. I have two presets set up in Audition (the software we use at church to record with) that first compress then normalize the signal. We save a .wav file, which is burned to a CD, then an MP3 which goes on the web. Since we started doing this, we’ve not had a single complaint about the volume level of the sermons on the CDs or on the web.

And again, I know I’m taking liberties with the concept of dynamic range here, and I know this is not, purely speaking, the most pristine way to record audio. So no flaming comments about the inaccuracy of my math or the flaws in my signal chain, OK?

Given the time constraints we’re under to turn these recordings around, and the fact that the FOH engineer has enough to do mixing the service, never mind constantly tweaking recording settings, this works really well for us.

Try applying some post-recording compression this weekend. Best of all, if you don’t like it, there’s always “Undo!”

Settings for Good Vocals

29 08 2007

Dave has an excellent post on the effects, EQ and settings he uses for vocals. Much of it applies to the Digidesign Venue he gets to use (lucky dog!), but he has a great section for those of us stuck in analog-land. If you’re not reading Going to 11, you really should be. Really.

IMAG — Solid Foundations

28 08 2007

As promised, this is the first in a series of posts about the equipment needed for IMAG. I’ve decided that there is way too much information to cover in one post, so I’m going to do a series. This has the added benefit of giving me fodder for posts for a while ;-).

Like any good project, IMAG success starts with a good foundation. In the case of video acquisition, that foundation is the tripod. Now, you can spend more on a tripod  than you can on a house (actually it would be a pedestal at this price point), but most churches don’t need that level of product. However, a solid tripod is essential to getting decent images on the screen. The reason is simple. What looks like a tiny bobble or stick in a pan on 7″ monitor is a 6″ shake on a 16-foot wide screen. Creating big shaky images is a sure way to drive your audience nuts.

Let me point out that technically, a tripod is a three-legged stand. You don’t attach a camera to a tripod, you attach the camera to the head, which is bolted to the tripod.  The combination of a tripod (the legs) and the head (the pan and tilt mechanism) makes up a camera support system, commonly referred to as a tripod. From this point forward, when I say tripod, I mean the entire system.

So what kind of tripod do you need? That depends. Mainly it depends on what camera you are using, but it also depends on how long of a lens you are using as well. A “long” lens is one with greater telephoto capabilities. It zooms in farther an is often, incorrectly, measured in x as in 20x zoom—more on this in future posts. Again, let’s consider the logic. When you are zoomed way in (try this with a simple camcorder), very minor camera movements create huge shifts in the image. That’s why it’s darn near impossible to handhold a camera and get a steady image when you zoom in.

Back to tripods, you need a tripod that is rated to handle the weight of the camera you intend to put on it, plus any additional gear (studio viewfinders, focus and zoom controls, etc.). There are basically two types of cameras most churches will use: ENG type cameras and Camcorders. ENG style are cameras that can be shoulder mounted, they often have interchangeable backs (for a recorder, or a studio output), and will typically have a 1/2″ or 2/3″ imaging chip. Expect these cameras to run in the $15,000 and up range. Sony’s DCX series and D-30 are examples of ENG style. They will generally weigh in somewhere around 15-22 lbs. Thus your tripod needs to be rated for such a weight.

Camcorders range from the small Canon GL1 to the larger XL2 or H1. JVC, Panasonic and Sony all make “prosumer” camcorders, some of which can work for IMAG (with varying degrees of success). These are typically lighter (4-9 lbs) and demand less from the support system.

There are number of professional tripod manufacturers, and it behooves you to stick with a well-known brand. Companies like Vinten, Sachtler, Cartoni, Gitzo, Miller and Bogen have been around for a long time and make a wide range of tripods for all types of cameras and budgets (OK, maybe not all budgets…). Personally, I’m partial to Vinten because I’ve owned 2 of them and absolutely loved them. They are not inexpensive, however.

Ideally, you want to try out the tripod before you buy it. One good test I like to do is to set the pan drag control (if the tripod you’re considering doesn’t have tilt and pan drag controls, keep looking), near it’s highest setting—this will make it harder to pan the camera—and try a pan. When you stop, the camera should stop, not stop then go back a little from where you came from. On lesser tripods, they will “wind up” when you pan, and when you stop, they unwind giving you unwanted movement. You should also be able to balance the camera in such a way that with minimal tilt drag you and set the camera up to 45 degrees up or down without it moving on it’s own.

Also ideal is the ability to add 2 control arms on the tripod, so you can attach zoom and focus controls.  These little tools make is much easier for camera operators to get good shots and not have their arms falling off after a service. Varizoom makes some really cool zoom and focus controls for both Canon and Fuji lenses (used on the ENG style cameras) and for mini-DV camcorders—very cool!

As I said, adjustable tilt and pan drag are a must, and the controls for both should be easy to get to and operate in the dark. Such a tripod will not be inexpensive (a quick search on B&H shows them starting at about $800), but you’ll never regret spending the money. You’re better off with one camera on a good tripod than with three on cheap, unsteady ones. Trust me on this one. You can also find some really good deals sometimes on used equipment at TVProGear and Media Concepts.

Whatever you do, don’t go into a photo store (or worse, Wal-Mart) and buy a “video tripod” for $50-100. It may be barely passable for producing the occasional video, but it will not serve you well for IMAG. Your images will shake, you won’t be able to follow the speaker well and you will frustrate your volunteers who want to do a good job. And one more thing, still camera tripods are an absolute no-no for IMAG. They are designed to pan and tilt the still camera into position and lock there, not move smoothly from point A to point B. Do not waste your money. Just don’t.

Also, you don’t want to over-buy. Putting a 5 lb. camera on a head rated for 15-22 lbs. will not work well. The camera won’t have enough weight to effectively drive the pan and tilt mechanism, and you will not get smooth results. You want your camera’s weight to fall into the middle of the rated range of weights of the head. Again, trust me on this.

That’s a brief primer on tripods. There is a lot more to them than I’ve covered, but these are the basics. If you have other questions or want me to cover other options, leave a comment and I’ll see what I can do. I can go on for a while about video gear…



25 08 2007

I’ve been thinking about IMAG (Image Magnification) lately. We currently don’t do IMAG at Crosswinds, but I’ve done a ton of it during my career. As I read through the stack of church production type magazines I get each month, it appears more churches are moving into the IMAG arena. It makes sense, as worship rooms get larger (it seems that 2000+ room are becoming more common), there is a need to help those in the service see those on the platform. I’ve shot 200 some concerts as well as a few dozen other events, and here are few things I learned along the way.

The image on the screen should be bigger than in real life.
Seems obvious, right? But I can’t tell you how many times I’ve looked up at the screen and noticed that the image of the speaker is smaller than the speaker is in real life. The reason is simple: Directing for IMAG is different than directing for a tape or broadcast mix. Most directors (and camera ops) are uncomfortable staying as tight as they need to for effective IMAG. There is a tendency to pull out and show the overall scene. But think about this—if you’re seated 150′ from the platform, you already see the overall scene; what you want is a close up of the speaker so you can see their facial expressions.

The other challenge with staying as tight as we need to has to do with lenses. Long telephoto lenses are expensive, but they are necessary to getting a useful shot. My rule of thumb is this: A standard IMAG shot needs to be head to waist or closer. Ideally, you should go head and shoulders. If all you can get is a head to foot, you will not have an effective IMAG experience (unless you have mammoth screens).

Shot selection should make sense.
If you’re shooting a speaker who stands at a podium, you really don’t need to keep switching shots. I’ve sat through events shot with 5 cameras. And because there are 5 cameras there, the director felt the need to use all five, all the time. Again, consider the goal of IMAG—to show distant viewers a close up of the speaker. Cutting back and forth between cameras is distracting.

If the speaker walks the front of the platform, having three cameras, house left, center and right, will allow you the opportunity to cut to the camera that the speaker is facing. But if the speaker pauses at stage left, don’t switch to the house left (stage right) camera just to “change it up.”

If you are shooting a worship team or a band, the focus of the IMAG should be the worship leader or lead singer. Having multiple stationary cameras in the house allow you to highlight different instruments occasionally, and adding a handheld stage camera does even more. However, keep in mind that the people in the congregation didn’t come to see a close up of the bass guitar players fingers. That can be a very cool shot—for a second or two between phrases of a song. But please, don’t spend an entire verse there (unless you are using instruments as a background for lyrics, which is a whole different style).

When cutting a worship team, the cuts should follow the music. A soulful rendition of Amazing Grace doesn’t require (or benefit from) 30 cuts a minute. However, an upbeat tune like Dancing Generation could be enhanced by a few extra cuts here and there.

IMAG and broadcast mixes are different and need to be treated as such.
There is a temptation to combine the two functions, IMAG for the worship center and a “broadcast” mix for the in-house CCTV network for cry rooms, or hallway monitors. This is rarely optimal, however. As mentioned previously, IMAG needs to be close up shots. A broadcast mix needs a mix of closeups and establishing shots. For years I was stage camera op for a music festival in Ohio. We were supposed to be there for IMAG—our shots were projected onto huge 30′ screens for those at the back of the 10,000 person crowd. However, the director wanted to make live concert videos. They looked great when we watched the tapes at home, but the crowd was gypped. That wide sweeping shot of the crowd that moved up to the stage (using the 30′ crane) looked really cool, but the poor folks in the back already had that view. They wanted to see Toby Mac, not the people in the first 15 rows.

It sounds like I’m repeating myself, and I am. It’s important to think of IMAG as IMAG and broadcast as broadcast (regardless of how it’s “broadcast”).

Regardless of what you’re shooting, or how you’re mixing, you need the right equipment. Few things are more frustrating than trying to pull together a good video mix using equipment that was not designed for it. In the next post, I’ll give you some of my thoughts on the equipment you’ll need if you want to get into live video.


Improving Videos – Don’t Zoom Pt. 2

16 08 2007

It occurred to me recently that I never finished up this series on improving your video production. If you’re a new reader, you can pick up part 1 here, and then pick up part 2a and part 2b. All caught up? Good.

As I said in Part 1, incessant zooming is one of the hallmarks of amateur video. That’s not a good thing. It was even the subject of satire some years back when “Wayne’s World” popularized the “unnecessary zoom” on Saturday Night Live. I’m not sure what drives people to zoom in and out of a shot, back and forth, all the time during the shot. Perhaps it’s because Sony conveniently located the zoom control right under your thumb. Whatever. Once you hit record, don’t touch that zoom button.

Again, the goal is to produce really high quality video. Even if we don’t have great equipment, we can still utilize production techniques that are well accepted and produce excellent results. That’s where “zoom discipline” comes in.

Take a look at a well-shot film or TV show. You will not see very many zooms. You may see times when the camera gets closer to the subject (called a truck), but more than likely it is not a zoom. That’s because filmmakers use prime (non-zooming) lenses almost exclusively. They use prime lenses because they are sharper and produce a better image, but it also ensures there will be no “unnecessary zooms.” They also take great care in framing their shots in a aesthetically pleasing manner. Too many amateur videographers simply zoom in and out instead of taking the time to set up a great shot.

So here’s what I recommend: Whenever you press record, don’t touch the zoom control. After the shot is finished (and the recorder is paused), then you can zoom if you want to to get a different shot. Work on framing your shot in such a way that it works, looks good and draws the attention of your viewer where you want it to.

Another tip is to take a cue from filmmakers: Start the scene with a wide shot, then cut to a close up. Then you can cut to a medium shot. You can use the zoom to get all these shots from one vantage point, just stop the action while you zoom and cut (just a cut, not a dissolve, or effect) from one shot to the next.

Try this out on your next video project. Start to think of it in terms of a series of shots that will piece together. As I write this, it occurs to me that some visuals would be helpful. I’ll work on coming up with some sample pieces to illustrate my point. And perhaps from there, we’ll go onto some basic editing techniques. In the meantime, go make a video–just don’t zoom!


Of Cables, Conduits and Labels

31 07 2007

Warning: Rant coming. It might be best to get the kids out of the room for a minute.

One thing I’ve discovered in the last 20 years of doing church tech (and other tech for that matter) work is that in any given cable installation, over a period of time, the once neatly installed cables degenerate to a mess resembling a big old plate of over-cooked #11 Vermicelli. I don’t know if there is a roaming squad of cable trolls who tangle it all up or what, but it’s been true of nearly every installation.

So last night I decided to pull all the cables in our youth ministry center and lay it out again. I wasn’t surprised that all the cables were twisted up, and that a bunch of stuff was not connected correctly. What really aggravated me was that I found a bunch of cables that were laying in the cable tray under the counter with no labels on them. There were RG-59’s that disappeared down a conduit without a trace of where they may go. I found cables running up to our RF DA in the ceiling without a single flag of tape as to which one was input and which were outputs (after toning them out I found out the input cable was connected to an output terminal, explaining why the system didn’t work…). I found eight 1/4″ lines also laying in the tray, with no idea where they go.

I’ve done a lot of wiring in my life, and I’ve learned a few things. One is that putting a label on a cable end doesn’t take that long, and it makes troubleshooting a lot easier. I’ve learned that in a month, I will not be able to remember where all the cables go. I’ve also learned that I will not be the last person working on the system. And this is where the aggravation comes in.

If you start running cables all over your church to connect rooms or booths or TVs or whatever, and none of them are labeled, at some point, something will get disconnected and someone will have to figure out what goes where. If everything is labeled, it’s a whole lot easier to track it down, especially in a large church. We have 5 theaters that are all inter-connected by unlabeled wires. Which makes the wires in the conduit useless. At some point, I will have to spend the better part of a day toning these lines all out and figuring out what goes where. That’s a huge waste of my time, and it could have been avoided by putting something other than a flag of red tape on the end of a cable.

I like to label everything. We have one of those nice label printers with a QWERTY keyboard on it, and I personally have gone through at least four 50′ rolls of label tape in the last year. I label connectors with the tape, and put clear heat shrink over the label (a cable tray full of labels that dried out and fell off is almost as frustrating as unlabeled cables).

While were on the topic of labels, make sure you label it so someone else can understand it. “To Lobby TV” might be a great label—if your church has one lobby and one TV in said lobby. However, when you add on in 3 years and have another lobby with another TV, things will get confusing. For runs that leave the room (whatever room they originate in), I suggest some type of code to go along with the label. If you have all your rooms connected with RG-59, perhaps tag each end of the cable with a serial number, like “RF-1,” “RF-2,” etc. You can also put something on there like “To Min Cntr” so that someone has an idea where to go look for the other end of “RF-2.” Same goes for audio tie lines.

I even label cables in equipment racks and behind soundboards and the like because eventually, it will need to be unplugged. Who can remember what gets plugged into where? If the connector is big enough I’ll label it with where it goes, “To Projector,” and what it gets plugged into, “Octo Output 1.” If it’s a small connector, I’ll just call it what it is, “RF Mod In.” The idea is that one person should be able to unplug everything, and someone else could plug it all in correctly, and without tracing lines all over the place.

Next time you’re about to string some cable over the ceiling, or push it into a conduit, think about putting a label on it. It takes just about a minute to do it, but I can almost promise you will save someone a lot of time trying to trace it out later. You can get a label printer just about anywhere;  clear heat shrink is cheap insurance and available here.

If you happen to be the one who ran cable all over Crosswinds with no labels, I hope I didn’t offend. Perhaps you can come in some Saturday and help me track them down and we’ll label them together.

Mixing Guitars

23 07 2007

Tim Corder found a good article in Mix magazine on mixing guitars. While Mix focuses on mixing in the studio, many of the concepts apply to us live guys as well. Check it out here…

Mixing Guitars