Monday, 8 September 2014

Helpful Hints for Self-Shooting Sound

Those of us who have been in this industry for a while remember when location shooting involved a two or three man crew, with plenty of equipment and the time to use it properly. Sadly, the world has changed and now this sort of thing is more often the domain of the lone researcher with a camcorder and a few sound bits.

I could rant about this and say it's a ridiculous thing to do, but sadly it seems to be the rule rather than the exception these days, so perhaps a few helpful hints might be useful? I wrote the following a while ago as part of a set of presentations for ITV production teams who might be self-shooting. Feel free to make use of any of it in your own shooting workflow.

Sound acquisition on location: A few tips for the best results

Tip #1: Hire an experienced sound recordist with appropriate equipment.

As a recordist, I have to suggest that first. It will cost you more to begin with, but your results will be immeasurably better from the start. And your editors will love you.

But you haven’t got the budget for that, otherwise you wouldn’t be reading this. You have to make do with what you have, and more often than not I suspect you’re on your own. So here’s a few suggestions to help both you and your workflow.

For this, I’ll assume you have a kit with at least a boom mic and pole, a radio mic and a set of headphones. Also that you have cabling to connect it all, and you’re connecting to the camera via two three-pin XLRs.

First thing: Get yourself familiar with how the bits connect together. Don’t wait until you’re about to enter battle!

Boom mic on pole, XLR cable to camera. Phantom power on if needed! Set input gain to “mic”.

Radio mic into transmitter, receiver into camera. Don’t mix the two up and wonder why it doesn’t work! Set input gain to “mic” or “line” depending on the output level of the receiver. Only one will look right; the other will either be massively loud or completely inaudible.

Headphones into headphone socket. And turn them up.

When you’ve done it a few times, it will become easier! The better you know your equipment, the better the results.

Hopefully you have now plugged it all up, and can hear something coming back on the headphones.

Second thing: If you do this, I GUARANTEE your sound will be improved.

You must LISTEN to what is coming in on your boom/radio and DECIDE if it’s good.

How do you know if it’s good? You need to get an idea of what “good” sounds like. Try recording yourself  with both the boom and the radio and then listening back. This is a good habit to develop at the start of each day to make sure your equipment is working; just because you can hear sound through your cans does NOT necessarily mean it’s being recorded ok! The boom should be no further than 18 inches from your mouth, and pointing at it. The radio should be clipped centre chest, no lower than nipple-height. Play both back , and listen how close they sound compared to the background noise. You should hear a cleaner, more direct sound on the radio mic, but the boom should sound more “natural”. THAT sound quality is what you’re aiming for when you start shooting, and you must always listen for any problems, both during recording and playback. Check particularly for a solid clean signal with no electrical noise or hums, which would normally indicate faulty hardware. There should be no excessive hiss or distortion if the recording levels are right. Which leads us to…

Third thing: Recording levels! There is an optimum level that you must record at; if you go below this you will get hiss or other noise, if you go above you will be in danger of distortion. Scales differ between cameras, but most have “0” at the top, with minus numbers below, sometimes with a mark at around “-20”. YOU DO NOT WANT TO GO ANYWHERE NEAR THE TOP OF THE SCALE! Aim for no more than around -10 for normal speech. If in doubt, err on the side of caution: a little noise is easier to fix than a distorted signal. To make the editor’s life easier, try and be as consistent as possible. Not always easy! Again, check the playback to make sure it sounds ok. If you hear anything wrong, you must mention it at the time when you’ve got a chance at fixing it. Don’t wait for the editor to find it!

Most camera have an auto level option. This seems like a useful thing, and indeed it will prevent you coming back with a distorted recording, but bear in mind that the auto level is not intelligent! If your interviewee stops talking, it will try and bring the background noise up to match his speech level, which will sound very unnatural.  This may however give you a useable sound which you might not get with manual level; it MAY for example be safer to use it if you’re on a top mic.

Nobody said sound was easy. So you have everything connected and working, and you’ve checked levels and playback. Now we move to where to stick things…

Fourth thing: Do you use the boom or the radio? You should have noticed how different they sound, so how so you decide which to use? Often the editor would like to have both available, so the safest choice is to put boom on one track and radio on the other. Seems like cheating, but it’s much safer for the editor to make the choice back in his nice calm suite where he can hear how it all fits together. Be VERY careful about committing to one or the other on location!

Booms sound more “natural” than radio mics; they match more what your ears hear. They MUST be close to the mouth (no more than 2 feet away) and pointing at it for best results. They are defeated by distance, loud background sound levels and by echoey/reverberant rooms. If outdoors they MUST have adequate wind protection, and they must be held carefully to prevent handling noise.

Radio mics sound more “focused” than booms; they reject background noise  and reverberation better, but can sound too clean on their own. They should ideally be mounted between mid-chest and neck. They are very vulnerable to wind noise outdoors, and to clothing noise at all times. Decide at the start if you really need to conceal them; this is a real black art and can be very hit and miss. If you have to do it; put them as near the surface as you can, and secure the clothing around them to prevent it moving. You CAN’T bury them under a coat and expect to get good results. Again, LISTEN very carefully to your results; if the mic sounds woolly and indistinct, or if it has severe clothing noise you MUST be in a position to hear it, and to try a different approach. Unfortunately there is no “one size fits all” approach to radio mic concealment.

Always ask yourself: Do I REALLY need to conceal them?.....

Fifth thing: LISTEN to your location!

When you go into the place where you’re planning to shoot, stop a moment and listen. What can you hear? Is it appropriate to what you will see? If not, can you control it or use it? A busy road next to your location will be noisy and you can’t stop it, but if you see it in shot your brain accepts it and it becomes more acceptable. If it’s still too loud when you listen through headphones then can you change the location? Remember as you listen the radio mic will probably sound better here.  (A good tip is to listen without looking at the lips of the talent; if you can still understand them this way then the listener who IS looking will have a reasonable chance.)

If you’re indoors, the sounds are more subtle. Listen for things like heating noise, fridges and fans. Turn them off if you can (remembering to turn them on again after!). Any noise which changes or goes across an edit will leap out later.

In either case, when you cut everything together, you’ll still have things which don’t quite sound right. Which takes us finally to…

Sixth thing: How to help your editor!

Good sound doesn’t just stop at recording the on-screen talent. If you’re recording in different locations at different times, your backgrounds will change whatever you do. To make your edits work, you need “clean” backgrounds to smooth over the edits. So, when you finish shooting in a location, take a few moments to record just the background sound. Even if it doesn’t sound like much, record 30 seconds of it with nobody speaking or moving around. The editor can then lay this over any edits which jump out at you because the background was a little different. Don’t forget to log these so they can be found easily!

All the above is just a start, but it’s a step in the right direction. It might sound a lot of hard work. Which indeed it is. But if you take the time to acquire good sound, and to understand why and how it’s done, it will improve your end product immeasurably.

Thursday, 6 March 2014

The Problems With R128

First off, a statement: I have no problem with the principle of mixing to a constant loudness, because it's how I was trained at Evesham 30 years ago and it's how I've mixed shows for 20 years. The idea is not new, but in recent years due to lack of training it's fallen out of practice and people have become slaves to the PPM without using their ears,

Second statement: I do not consider myself to be the greatest mixer in the world. I could be wrong about all this. But I DO mix 10+ hours of network TV every week, and I have lots of chances to measure and experiment. There are some major problems I have found, and nobody has yet been able to answer them; there are many "Heads of Technology" who are quoting me chapter and verse on R128, but few craft mixers who have actually done it.

I'll start on the small bits and then work up.

Firstly, why are we doing this? I thought the biggest complaints from viewers were about adverts and promos, yet these are not covered by R128! There WILL be a spec for them, but why are we going to all this trouble when all we needed to do was tame the commercials. Incidentally, the last year has seen a reduction in advert level to the point where there doesn’t appear to be a major discrepancy any more.

Secondly, the measuring algorithm. This whole thing is based around a metering system which is meant to tell you how loud something sounds, rather than how much it meters. Hang on, didn't we already have something that could do that? Like a pair of EARS? Wouldn't it have been a lot simpler to just train people to use the PPM and LISTEN, like I was taught? Then we could have kept the system people were familiar with. I even had an acronym for this. 

P.E.T.: PPM. Ears. Training.

But if you're going to replace humans with machines, then you will have made sure that your ear-measuring meter actually matches what a human ear hears? When we moved to our new home at MediaCity our studio gained a loudness meter, and I started measuring everything we did. I found that between shows, with a fixed monitor gain, speech which sounded constant to me was reading DIFFERENTLY on the loudness meter. Even within a run of the same show, there were inconsistencies. It seems that the faster the speech, the more it "fills up" the integration, even though it doesn't sound louder to the ear. I've seen errors of up to 2 LUs between shows; this is as much as the variance allowed on the DPP spec!

Now I'm aware that my opinion alone may be incorrect, so I've asked a few people, both sound and non-sound staff, what they thought, taking care to word the question in a way that doesn't influence them. They seem to agree with me. This is, of course, not a scientific study, but it does seem to confirm what I think I'm hearing. 

Maybe hearing is such a subjective thing that any algorithm to measure it should take into account a lot more than just the "area under the curve" of an integrator?

Thirdly, the selection of the "Integrated" value as the criterion for program acceptance. The idea that the viewer cares about the overall level of a program is, I think, flawed. What the listener cares about is having to turn their TV up or down, and the thing that causes this is dialogue variation, whether the wrong level or with too much dynamic range. The EBU say that this allows for greater dynamics within a show, but with no restrictions on short-term level variation it is possible to mix a program that has so much dynamic range it's unlistenable even though it hits the numbers. This was, of course, possible with the old system, but I thought the new one was meant to sort this out? I've taken show segments, made them unlistenable with massive level variance, and then submitted them for testing to QC. All of them passed! How can this possibly benefit the home viewer? Again, if the new system is no better, why not stick with the old one and train people to use it properly?

Fourthly and finally....

Following on from the above, there is a major problem with only specifying integrated as a delivery requirement. This is a major practical issue for me, and so far I have conflicting replies from anyone I've asked. Bear with me, this may take a while to explain.

First, a question, the answer of which is very important: 

"Across a network, should the average loudness of normal presenter speech be constant between shows, and is so what should it be?"

The official answer I had from the DPP is "Yes, -23LUFS", as is that of Hugh Robjohns in this month's Sound On Sound article on loudness. There is NO information on this in the delivery requirements.

To understand the problem, we must follow through the implications of a Yes or No answer to the above. We must also look at the basic components of a TV show mix, and how they interact.

A TV studio sound mix typically has three components: Speech, Music and Applause/FX. These are balanced to sound correct relative to each other, and the idea is to maintain an appropriate dynamic range for the home listener. 

The problem is very simple. For some shows, the speech is the loudest part of the show, for others the quietest, and for some it's in the middle. 


Speech is loudest: Newsnight
Speech is in the middle: Countdown
Speech is quietest: Jeremy Kyle

I know these are on different networks, but the principle is valid regardless.

So,consider the YES case:

We wish speech to be constant between shows. The DPP recommend -23 LUFS, so that is what we do. 

This is easy; there is mostly speech and very little else, so that works giving us a final integrated value of -23 LUFS.

                                                                                                                                                                                                            This is also easy; there are quiet sections (the clock bed) and loud sections (the applause and music) around the speech which more or less cancel out to give us -23 Integrated again.

                                                                                                                                                                                                            This is a problem. The speech is the QUIETEST element, and there is much shouting, music and applause which are all louder. So if we put the speech at -23 LUFS then the final integrated reading will be well over -23 because of the louder bits. Typically the show sits at around -19 LUFS using this method.

RESULT FOR THE "YES" CASE: The viewer is happy, the mix sounds right but we cannot conform to the integrated DPP spec for R128. 

Now consider the NO case:

This is easier from our point of view. If we don't have to match speech levels, then we can keep our mixes the same, and simply offset the level to hit the DPP spec.

RESULT FOR THE "NO" CASE: The DPP spec has been satisfied, the mix sounds right but the viewer is still left with inconsistent dialogue levels and STILL has to turn their TV up or down between shows. Nothing has been gained.

There is a third case: We remove all dynamics from our audience shows so everything is at -23LUFS. 

RESULT FOR THE THIRD CASE: The DPP spec has been satisfied, the viewer has constant loudness, but the whole experience of the show is lost, and everything sounds like Radio 1. As a craft mixer, I don't consider this an acceptable solution.

Although the DPP recommend the "Yes" case, in practice the "No" case is what is happening. Mixers can set their speech as they wish to allow higher or lower levels, and it all seems fine if you consider a show in isolation and NOT as part of a greater network. We end up with what we had before: inconsistent levels between shows which defeats the entire object of R128. 

All of this results from the decision to use the "Integrated" value only, which as you see causes major problems. It's interesting that our European cousins have all picked different things to measure from the original EBU spec. The American networks seem to have realised the problems, and often have rules for dialogue levels as well as the overall show level.

This last question in particular is the one that I have never had properly answered,  Every time I raise this, I get chapter and verse of R128 quoted at me, but the questions are never answered and eventually everyone goes quiet. 

I am NOT trying to be awkward; I believe these are genuine concerns, and I want them to be answered in a satisfactory manner. The new spec is only acceptable if it works for ALL genres, and it clearly does not.

I believe we are throwning out a standard which had flaws but worked fairly well for 80 years, and we are replacing it with one that won't even solve the problems it was meant to.

Why did nobody ask the people at the sharp end?