Production sound mixer Deian Humphreys tells Adam Savage how close collaboration and kit that can cope with noisy sets helps obtain good dialogue for one of the world’s best-loved sci-fi shows.

It’s become something of a tradition for countless families not just in the UK but all over the world to tune in for the Doctor Who Christmas special every year to see what kind of trouble our Time Lord has got himself into this time, and 2016 was no different.

Last month’s festive episode, which saw The Doctor join forces with a journalist and a superhero to save New York from a deadly alien threat wasn’t just the ideal piece of telly to enjoy during the post-dinner stupor; it also gave fans their much-needed fix while they wait for the next full series of the sci-fi show, which has been produced by the BBC since 1963 with Deian Humphreys handling the challenging role of production sound mixer for the past three seasons. We managed to catch up with him during filming of his fourth series – a job that had taken him away from a frosty British December to the more pleasant climes of Tenerife, Spain.

For a programme that is centred around visits to different time periods and other worlds entirely, location work is a necessity, but not as much as you might think – around 70% of the work is done in the studio or in the Cardiff area. And even though the amount of time spent filming may at first sound generous when other crews are often given a matter of weeks, Humphreys does not have it easy.

“Normally jobs are ten weeks or maybe three months – six months even – but this is nine months and there’s no margin for error. You can’t have your equipment fail on you so I’m not afraid of spending money and I will buy the very best of everything,” he explains. “I have not had my equipment let me down – you get the odd broken lapel mic where an artist has ripped the head off but I’m talking about recorders that can record sync audio without drifting for 11-hour days. Our normal day would start at 7:30am, we work through to 7pm with only half an hour for lunch so the machine is on almost all day and is required to operate in all sorts of conditions.

“At the front end of the whole kit is my Sound Devices 788T, which is a bulletproof piece of equipment that I just adore and has very, very rarely let me down. In a science fiction programme like Doctor Who one minute you could have whispering dialogue that would all of a sudden erupt into levels that could blow your ears off almost, but the 788T copes admirably with all of that.”

These sudden bursts of sound may be necessary to help give viewers the sensory thrills that they’re used to experiencing with Doctor Who, but it does create a few problems for Humphreys when trying to achieve his main goal: capturing dialogue that is as clean as possible.

“That’s the number one objective. There are all sorts of things that prevent us from doing that of course: smoke machines; wind machines; snow machines; sets made of wood so when people walk on them they sound awful so we’re forever laying carpets, hanging curtains or blankets up to try and deaden places; there’s a generator that I’m always trying to get parked as far away as possible from the set. We’re also constantly having to battle against atmospheric conditions as well like traffic noise or aeroplanes.”

Keeping the noise down

As we all know, sometimes these obstacles cannot be overcome on set and will lead to a separate ADR session or become a clean-up task for post-production later on, but Humphreys won’t allow this to happen unless there is absolutely no alternative, which is why much of his kit was selected with noise reduction capabilities in mind. But that’s not all he was looking for when he made his picks, particularly with microphones.

“I decided that Schoeps mics are the ones for me because of their warmth and the natural way they sound. In my arsenal I have two digital SuperCMIT mics and those are the ones that we’d normally use for external locations,” he notes. “They record two ‘legs’ – one is a treated signal, the other normal – so you can set the gains and listen to the normal signal and the treated signal side by side and the difference is incredible sometimes in the way that it can get rid of background noise. I’ve been told by the dialogue editor that it can be the difference between having to record ADR and not so in that respect it’s an invaluable tool.

“One thing I did invest in for this series is a CEDAR DNS 2. I was told that we were going to have to do a lot of ADR because of the traffic noise so I thought ‘I’ll be the judge of that’ and was blown away by what it was capable of.”

In fact, the purchase was made in the run-up to the filming of the Christmas special, presumably to prepare for the inevitable onslaught of deafening snow machines? Well, although that usually is the case, if you did watch the last festive episode then you may have noticed a surprising lack of wintry conditions, which was good news for Humphreys on the noise front. That didn’t mean there weren’t things for him to worry about, however.

“One of the characters was a superhero with a suit that had this amazing squeak to it. Every time he moved it made this awful noise and in the end we were able to limit it a little by using a bit of talc or tape here or there. We also like to have a close relationship with the costume department because putting mics in clothes presents all sorts of problems. 2nd Assistant Sound Chris Goding will be forever tinkering with radio mics to get them as clean as possible.”

It works both ways

As well as collaborating with other units like the costume people, it becomes clear when talking to Humphreys that making life easier for the post team also ranks highly on his list of objectives. Others in his position will say the same, but he really does seem to go the extra mile, and one other crewmember he is always looking to impress is dialogue editor Darran Clement, who it turns out recommended him for the Doctor Who role.

“He [Clement] loves the way that the compressors are set and how the mics sound. The workflow that we have is great and it’s one of the things that’s really important when you’re working – I would always do a job and speak to whoever’s doing the post-production sound before I start shooting so you already have conversations about how they want things and how you achieve that.”

And his relationship with the guys in the studio goes a lot further than the occasional quick conversation when a problem arises. “I always think it’s good not just for them to come to us and see what we’re up against but it’s also good to go in and see what they’re capable of. Sometimes we’ll go and see post-production sound and we’ll talk to the guys there and see what they can do. The software they have to hand is incredible – sometimes you think ‘oh god they’re never going to be able to use this’ but now they have iZotope [RX] and things like that to clean up all the dialogue and it’s a real eye opener for us.”

Unfortunately, there are times when unwanted interferences become too much to overcome. The show might take its characters to all sorts of places, but one location that has remained constant since the very beginning is the iconic craft that The Doctor uses to travel through time and space: The TARDIS. As is often the case, the set looks fantastic – and just like what you might expect the inside of a time machine to look like – but it wasn’t designed with the sound guys in mind, and hasn’t got any better over time.

“It’s a horrendous set to work on! It creaks, it has smoke machines that are on constantly, the whole floor has become unsettled and it’s now terribly squeaky,” Humphreys says. “Post are forever having to clean up the dialogue that we do there. I carry an enormous amount of rubber matting that we put down whenever we don’t see the floor.”

With Doctor Who being a two-camera shoot, it is not uncommon to come across certain issues when faced with wide and tight angles at the same time, which is where Humphreys’ arsenal of Audio Limited 2040 series comes into play, and not forgetting to make sure all his tracks are nicely organised for the editors before they’re sent off.

“We will always put any speaking character on a radio mic, but we’ll always try and capture a sound on a boom – expertly handled by 1st Assistant Sound Tam Shoring. All those radios are recorded separately and I make sure that I label them with the character name or what that mic is, where it’s planted etc.”

Humphreys also believes that a production sound mixer should do exactly what the role suggests, which might sound obvious, but this isn’t always the case.

“I always follow the script really closely. I used to be a sound supervisor for The London Studios and worked on This Morning so having done live TV I know that if you have ten people having a discussion about something you can’t just leave ten mics open; you need to follow that conversation and that’s something that’s been instilled in me since those days.

“I’m a production sound mixer so I should be mixing, and I do – very hard. Sometimes you hear about sound recordists where if they have two booms and four radio mics then they just leave them open. Well I think that’s atrocious and it’s awful to listen to when you’ve got a scene where there’s six mics open and only one person talking.”

“What I strive for is as good a mix as possible for people to listen to – that’s something that’s important to me.”