This blog entry is to complement the video A short film about sound I made on April 2nd 2013 for #TeachMeet #Ukedchat #TeachTweet Session 147.
Because of the limit of 5 minutes, the film could only lightly skirt the theory and process of doing voiceovers. This blog entry augments the film with further detailed references and resources around the topic so people curious about the process can take it a little further if they have the time, inclination and money.
Bear in mind audio kit is getting cheaper and cheaper as more and more independent film and podcast makers are taking up the challenge of going online with their own media. I have had to update prices twice when making the film they have dropped so much in the interim.
I am by no means an expert but have picked up some of these tips over the years; I hope you find them useful for making your own media. There are links to online resources at the end of the blog. I have aggregated, collated and archived links to films and webpages dealing with topics around film and sound in a lot of detail. The information is there if you wish to take it further.
Although this is advice specifically for making voiceovers for TeachTweet videos, some of the sound techniques and equipment can be used to capture better quality film sound generally.
The film below deals with the use of some of the microphones and kit I mentioned in the last TeachTweet discussion online. Someone suggested I make a presentation about microphones available and how to record better sound. The film and this blog deals with some of the ideas underpinning ways in which to record better sound on presentations. I hope you find it useful.
THE BASICS OF SOUND AND MICROPHONES
Basically microphones are instruments that capture acoustic energy and turn it into another form of energy (electrical). Some are better at doing this than others!
They turn sound from an acoustic into an electrical signal. Mics are one kind of transducer – a transducer is a device that converts a signal in one form of energy into another form of energy. Sometimes the conversion isn’t very good and the ‘signal’ needs a boost.
Mics increase the power of the acoustic energy, converting it into electrical energy. Then using electronic circuitry the computer converts this electrical energy back into physical energy via sound processors and then through speakers and headphones. These come out in the form of sound waves.
COMPUTER MICS AREN’T THAT GOOD
Some”built-in” mics in computers are not very good at doing this so you’ll have to boost the signal in some way without boosting the “noise” along with it. There are several inexpensive ways you can do this…
BOOSTING SOUND ON THE CHEAP
PROXIMITY – GET CLOSE!
The strength of the signal may be boosted using proximity. Bring the mic close to you – if you can’t then you, go to it.
Recording a voiceover is not as difficult as trying to record someone walking around the room, where they often wander in and out of microphone range, so make it easy on yourself; get as close as you can to the microphone without making the signal distort or “clip“.
This is the most common mistake that people make when recording a voiceover. They sit too far away from the computer’s inbuilt mics and the sound is tinny and echoes around the room or there isn’t a strong enough signal and too much background noise intrudes on the soundtrack giving that marvellous WWII retro London Calling feel to it.
So even if you increase the gain you get a louder hiss or hum. This may be acceptable for what I call “process” audio (i.e. audio or video that just captures what people are saying and not designed to sound like a hollywood film or TV) but this won’t do you (or your audience) any favours if you are trying to record a clear signal for a voiceover.
Your ideal is to capture clear and ‘easy to hear’ audio. Good signal and not so much noise. People’s hearing changes with age – I am blessed with extremely good hearing for my age – my frequency range is quite wide. Bear in mind new Loudness guidelines are being introduced for professional broadcasters.
WRITE A SCRIPT FIRST
Unless you are very talented and good at off the cuff, ad-hoc speaking then write yourself a script before recording – then put it into something like the free “cue prompter” online; then read it close to the mic! It makes all the difference.
Once you have done this then you can always adapt it later and use it as a basis for timings for images, animation or video you might want to edit together. I really like the iAwriter App – because, besides being synched to all my devices and computers, it tells me how long how many written words are in terms of time.
You can hear, and see the difference of proximity in the film below. The only equipment I used was the free software program Audacity and a laptop. However I changed a couple of things to make the sound better each time. Look at the waveforms as well…
Of course the drawbacks to this are that the laptop may well overheat – you’ll be short of air and the recording you’ll get will be more towards the “bass” side of things so not so balanced – it may be richer but maybe not to your taste.
Once you start to get picky about the sort of sound you record then it is time to examine using different types of external microphone.
GOOD VOICEOVER/ PODCASTING MICS FOR EVEN BETTER SOUND
The microphone I mentioned in the last TeachTweet ukedchat discussion was the Audio Technica ATR2100.
It is a cardiod microphone – i.e. one whose cardioid polar pattern reduces pickup of unwanted sounds from the sides and rear. Basically it cuts out unwanted sound from the sides if pointed at your mouth or if you speak across the top of it from the side. This makes it ideal for podcasting.
The quality is phenomenal for the price but the sad fact is that it is only available in the United States or on ebay. So you will be liable for import charges and VAT which, if buying for the school, you can claim back.
The podcasting App used in the video above is called BossJock Studio for iOS – it’s a wonderful app.
The camera I used was a Logictech Pro HD 920 Webcam
The iRig Pre has also been hacked to work as a pre-amp with DSLRs – see this blog. http://www.dslrfilmnoob.com/2012/11/22/irig-pre-dslr-audio-hack/ DISCLAIMER: This invalidates the T&C’s obviously and could be dangerous but if you are an inveterate tinkerer that is a very cheap movie camera sound pre-amp. To be able to use the iRIg Pre without opening and soldering it buy one of these as outlined here http://www.dslrfilmnoob.com/2012/11/23/irig-pre-hack-testing/
WHY SMALL MIXERS ARE A GOOD BUY
The mixer has the added advantage of being able to mix in other sounds like line inputs RCA or Phono plugs from Vinyl, Tape, Video recorders, amplifiers, TVs etc. I regularly use this mixer to make better quality Skype calls. I have even used it with wireless microphones to record and relay TeachMeets in real time over the internet. The only drawback is the sound quality is limited and there are only a few inputs. If you were running a radio station you might need more for guests and other inputs. But for around £35 and dropping in price – this is one of the best buys out there!
Both the iRig pre and the cheap Behringer Xenyx302 Mixer have a pre-amp in them which helps to boost the signal from the mic. The mixer uses the computer’s power and the iRig Pre has a removable battery to power the mic.
Apple’s Camera Connection Kit allows you to connect up USB audio devices but they often have to be powered or go through a powered USB hub first.
The Procaster is another, higher quality podcasting mic used by serious internet broadcasters.
The NTG2 mic is often the one you see interviewers holding on TV – it is usually covered with a Dead Cat wind muffler to stop the wind blowing across the mic and causing distortion. If you can ‘Boom‘ the mic as shown in the film it is very useful for recording more than one person.
Shotgun mics (super cardioid mics) have a very narrow directional recording window.
Imagine a large cylinder over the mic extending six feet or more. Nothing outside that ‘cylinder of receptivity’ will be recorded – that’s not exactly how it works but basically it has very, very precise recording within a very narrow range. Excellent for doing interviews in busy crowds and therefore why interviewers and TV people use it. You often see “Boom operators” with very long extended Boom poles on Question Time.
Having them hang over your head pointing down makes it easier to capture the sound of someone talking from a much narrower range than on top of a camera. That’s why broadcasters get boom operator to do it. In the film I merely put it on a cheap mic stand and pointed it downwards. It gets an excellent signal this way.
I like and am willing to pay for the quality that comes from Rode Microphones – a shotgun NGT2 costs about £170 but you can get really cheap shotgun microphones for about £15 here:
There is a really useful blog entry at Oliviatech.com – How to get the most out of a cheap DSLR Shotgun Microphone here:
There is more information in the Licorize booklet I am constantly updating at:
This lists a couple of other cheaper mics and also some speciality microphones if you want to do interviews.
YouTube Playlists on Audio: