Friday, 23 November 2012

Nick Way on Sony Z1 Audio

nick way
In this article I will describe the sound aspects and features of this lightweight and versatile broadcast capable camera and how I think the best results can be achieved.
A little about me
nick way I have been running short courses for Sound Recordists as well as production teams for many years now, first with Ravensbourne College, and more recently for Bill Curtis Associates. I also lecture and run seminars. The best part of these sessions covers how microphones work in various acoustic environments, this then progresses on to microphone and recording techniques and various types of audio equipment. I hasten to add that I am a freelance Sound Supervisor in studios and Outside Broadcasts, as well as a location Sound Recordist and this is my main income, so I am primarily a practitioner of 25 years experience, and a tutor secondarily.
The Sony Z1
sony z1The camera is aimed at the semi-pro market. It is somewhat larger and more versatile than your average home camcorder, but excellent for the professional videographer, as some features are very similar to a professional Broadcast camera. It is also gaining huge favour with broadcasters as a replacement for the PD150 and PD170 for “fly on the wall” documentaries because of the superb picture quality, ease of use and small size. It can also be coupled to professional balanced sound equipment using industry standard 3-pin XLR connectors.
From the video side of things, I am sure the Z1 is a great improvement, over previous SD camcorders, allowing high definition DV recordings, which can be worked on in native HDV or down-converted to SD. Unfortunately, I am convinced that many Z1 owners are unable to record high quality sound despite the Z1’s audio capabilities.
sony z1 micWhen I first looked at the Sony Z1 and spoke in depth to my colleagues about it, it would appear that the Z1 is a superior design with regard to its sound capabilities than its standard definition predecessors i.e. the PD150 and PD170.
Although the Z1 is aimed at the lower priced end of the market, it is fairly rugged and like the older PD170, also has balanced XLR audio connectors, which have been positioned nearer the centre of gravity just in front of the hand strap. This is a great improvement over the PD170.
It is said that: “to achieve the best quality location sound, employ a Sound Recordist!” and that is very true, but I believe the second best is to get trained. There are many courses available to explain the principles of sound and sound acquisition and having a camera that will record high quality “bad” sound won’t help.
Z1 Audio Features
audio settingsEnough of the waffle - let’s have a good look at the facilities offered with this hardware. First and foremost, this machine has an on-board “stereo” microphone. This is as much stereo as a kid’s audio cassette player, but it is fine for picking up a guide audio track for syncing in postproduction, such as a music video. I suppose it might also be passable for background shots, which are intended to have music or commentary over them. Fortunately we are able to by-pass the built in mic with great ease and instead use the professional XLR microphone connectors near the front right of the camera. The microphone clamp nearby is very similar to those on a professional broadcast camera and it is this very clamp that I recommend you should use with an additional high quality microphone. You can always degrade audio in postproduction, but if you start with bad audio, it can only get worse! Rubber inserts can be obtained for different microphone diameters when using, for instance, a Sennheiser MKH416, MKH60 or the cheaper K6/ME66 combo, but I still think the best method is the old tried and tested gaffer tape wound round the mic body a few times; solid and reliable. If it can work on Outside Broadcasts covering boxing, helicopter arrivals, football and most other events, then why waste the money on anything else?
audio settingsThe switches and adjustments on the Z1E are mostly software controls and are found in the menu, unlike the professional cameras which have the important functions as obvious switches and dials. The system takes a little getting used to, but with practice it all becomes reasonably straightforward. Personally I think the first place to start is by deciding how to cover the audio for your shoot - in the simplest case you might use a gun, or rifle mic, and fix it as mentioned above. Will you need this audio on both tracks on the tape or you could use a different microphone such as a hand-held reporter’s mic or a personal lavalier mic? In either case you will have to go into the menu and change some audio settings.
Phantom Power
Depending on the type of microphones you use i.e. phantom or non-phantom, you will need to set the phantom power on the Z1E, this time it is done using real switches! If your microphone takes a small battery such as a AAA, then you should select ‘Off’, if on the other hand your microphone does not take a battery (Sennheiser MKH416 or MKH60 phantom for example) then you should select ‘On’ for the phantom power setting. Traditionally phantom power is supplied at either 48volts or more uncommonly 12volts, but Sony have chosen to supply it at “approximately 40volts” - why they didn’t go the extra few I don’t know. Most microphones should be fine, though, but it does makes you wonder.
sony z1 xlrOne enormous plus for me on the Z1E is the audio level controls. They are clear, obvious and well protected as well as being easily adjustable, and it’s easy to undo the cover even if you don’t have long fingernails. In the old days on professional cameras, the practice was to cover the level controls with tape to avoid knocking them, but this meant you couldn’t see whether you had knocked them or not and anyway the cameras, worth thousands of pounds, became really sticky and nasty. I do hate the overuse of tape on location.
Menu Settings To Watch
One other major point worth noting is that buried within the menus are some audio level adjustments which could quite easily fool the unwary. You can reduce or increase gain within the camera by lumps of 6dB between -18dB and +12dB. Unless you are really fully aware of what you are doing and why, I strongly suggest you leave well alone. To coin a phrase: “for advanced users only”; this could cause all sorts of problems with potential overload or under-recording. z1 audio potsAnd whilst on the subject of menu adjustments there is a setting called “noise reduction”, I and several colleagues are still not quite sure what it is for but think it could be for reducing the mechanical noise picked up by the on board microphone, so it might be wise to leave it well alone. It can only serve the purpose of degrading your beautiful audio! There is also a wind filter, indicated by a symbol of a windsock, to reduce the bass sensitivity of the camera input - what is known in the trade as bass roll off or attenuation or a high pass filter; you know I really don’t understand why nearly everything in broadcast needs three ways of describing or labelling one thing. It’s really maddening, especially when you try and teach new concepts to beginners – anyway with that off my chest! What I need to say about this switch is don’t. It is far too brutal. If you have a proper microphone in the first place with a proper windshield you shouldn’t need it, especially if you have a mic like the Sennheiser K6/ME66, which already had a bass roll off switch on it.
Right, now we are ready to record. We have chosen how many microphones, which type and whether they need powering or not. We have chosen which tracks to use on the camera and have set the recording levels. If by mistake you leave the “Auto” switched in for the levels, it’s not too much of a concern, and unlike the old systems, which used to raise and lower levels quite dramatically, this control seems to just give a fixed amount of gain to the system and add a limiter to prevent overloading. z1 rearAlso be aware that the peak limiters can still be in circuit even though the inputs have been switched to manual. Now it’s time to plug in our cans, that’s broadcast lingo for headphones. It is now time to be honest and admit that we sometimes make recordings without actually listening to the audio coming into the camera - after all it is only the pictures we need to worry about right? wrong! I would imagine at least half of you use headphones for audio monitoring purposes during your shoots; I really appreciate that. For the rest, might I suggest you buy a decent pair of ‘enclosed’ headphones such as the Sennheiser HD25 (around £165). I hope it is obvious when I say that if the sound is bad coming through your headphones when you are recording, it certainly won’t get any better later. My monitoring your audio at the recording stage allows you to hear any discrepancies and fix it there and then, potentially saving you money on a re-shoot. Again, I reiterate that you can always degrade the audio later if you wish. Be warned though, this camera provides quite a low monitoring output level, so in a loud situation; you may not be able to hear very well hence the need for ‘enclosed’ headphones that block out external sounds. In the menu you can decide to listen to just one of your channels or both, as in stereo, but it can be a little confusing if you have different microphones on each channel, so it is best to choose just the one, the most important one. For example, if you are using a lavalier mic clipped to a presenter’s tie as well as a rifle mic on your camera for ambient room sounds, then you would monitor your presenter’s lavalier mic.
Portable Mixer
mixpre mixerSo, we have made our recordings and are happy with the results, but what if we really want to move up to the next plane? What if we really want to improve our control over the quality of sound? I always recommend a small two channel location sound mixer made by Sound Devices called a MixPre. This small and light portable mixer has amazing specifications and runs for several hours on two AA batteries and I reckon it can be operated by just about anyone with a little technical knowledge. It will supply a line-up tone, which I think is vital in this day and age of digits and lap top editing, to give us some idea of what parameters we are working within. I am sure it is all just fine in a domestic situation, but please, we do need to know where we are, so we don’t overload the recording system, or don’t introduce too much amplification noise into the equation. We must try and keep some standards. Phew, there I go again on some sort of rant!
z1 and mixpreThe MixPre will supply good quality amplification, using transformers on the inputs. It has two stages of bass roll off (or whatever you wish to call it), can supply phantom power at 48volts to your capacitor microphones and has high quality adjustable peak limiters. It will allow you to send either input channel to either or both outputs, and quite importantly it has a good headphone amplifier, so you can hear what you are recording very clearly. The LED level display works at three light intensities, the highest of which I would recommend for working in the sun in California – it is ridiculously bright. If you do need to take an audio feed for a transcription recording for instance, there is a 3.5mm jack socket which will connect straight to a domestic recorder. The MixPre provides a line-level output so make sure you select the input sensitivity in the Z1E’s menu from “mic” to “line” otherwise you will be sending about a thousand times more level (60dB) to the camera, which will result in massive overload and distortion; this is bad. A couple of years ago I turned up at a news conference and a BBC cameraman looked down his nose at my MixPre and wanted to know what it was. I explained what it did, and he seemed very impressed and gave the indication that he would go out and buy one almost immediately – amazing! It is a well-built and well-conceived item that is just perfect for unobtrusive and lightweight videography that seems to be the fashion now.
z1 lcdNow, on to perhaps the most important bee in my bonnet. Sound with pictures is often neglected through sheer ignorance. It is no one’s fault, but when you talk to someone face to face you can obviously hear them, thus it is assumed that if you can see them on the telly then of course you will hear them; naturally. I was always amused that my grandmother used to say of singers on television that “in my day no one needed microphones”. What on earth were they meant to do - shout at the world? On so many of my training courses I have young people who have been taken on by companies and are told to go and “do sound” with no training except how to switch the kit on and turn the knobs; this is criminal behaviour and can often knock fragile confidence. I have had camera assistants, researchers and runners who come to learn, and leave armed with the knowledge and confidence to tackle anything. I believe that things are now changing and there is the realisation that we really do need to try and acquire the best audio at the shooting stages, rather than tying a rescue attempt in postproduction, which is a time-consuming nightmare at the best of times. Through training we can learn to cover audio professionally and spend more time on the art and content.
The Sony Z1 is an excellent camera, and in the right hands can produce stunning results; just don’t let the audio side of things let an otherwise superb production down. Good luck.
Recommended book:
Audio for Single Camera Operation by Tony Grant. Focal Press - ISBN 0-240-51644-3
Recommended web sites:
Institute of Broadcast Sound: www.ibs.org.uk
Bill Curtis Associates: www.bcassociates.org
First Sense: www.firstsense.net
Nick Way MIBS: www.nickway.co.uk
Nick Way is a broadcast Sound Supervisor and Location Recordist as well as Trainer and Tutor. He started his career at BBC Television Centre aged 20 having enjoyed sound all his life and worked his way upwards following the established career path, working on all programmes from studio dramas to kid’s shows and situation comedies. He left after sixteen years of service and has now been freelancing for ten years across many companies. Nick works for shopping and quiz channels all the way up to BBC Match of the Day and Head of Sound for the G8 Summit at Gleneagles.

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