Studio SOS: Hans Zimmer

World‑renowned film composer Hans Zimmer, this month's Studio SOS candidate.

When legendary film composer Hans Zimmer asked us to help improve the acoustics in his temporary London studio, we were only too happy to oblige!

Our readership at Sound On Sound is nothing if not eclectic, spanning buskers, bankers, doctors and music professionals. We've had Studio SOS requests from all quarters, but I was still a little surprised when we were contacted by Tom Broderick of Remote Control Productions (formerly Media Ventures) to say that Hans Zimmer wanted to know if we were interested in fixing up a couple of production rooms for him to use in London. After all, Hans' studio in Santa Monica looks like how I'd imagine Batman's library to be — if only Batman could afford it!

To cut a long story short, Hans was temporarily leaving his US facility to work in a small suite of three adjacent cutting rooms at De Lane Lea studios in London's West End, where he planned to spend the next two months composing and recording the score for the second Sherlock Holmes movie (Sherlock Holmes: A Game Of Shadows). Both he and co‑composer Lorne Balfe had similar rooms measuring around 5.1 x 6.8 x 3.7 metres, with no treatment on the solid brick and bare plaster walls, other than some hastily‑hung blackout curtains. A third room situated between them served as the machine room, and housed seven large racks of computer hardware that Hans had shipped over for the project. The brief, in Tom's words, was to come up with "basic, inexpensive, quick, non‑invasive acoustic treatment” — so not too different from many of the other Studio SOS jobs we've undertaken! But a major obstacle was the lack of parking in the area, so any materials we needed would have to be either carried with us, or shipped to the studio beforehand. Tom said he already had two boxes of Universal Acoustics foam tiles that he hadn't yet used, and a quick call to Auralex yielded an agreement for them to ship a box of their foam panels directly to the studio, so that we'd have enough to treat both rooms.

Hans' temporary composing suite at De Lane Lea studios in Soho. Ideally, the setup would have been rotated so that the speakers were firing down the room's longest dimension, but the length of cables going to the machine room, and the need for a sofa at the back, meant that this wasn't practical.

We decided that the only practical approach would be to make two visits; one to find out what needed to be done and another to do it. Tom greeted us on our arrival and showed us the rooms in question, which were already kitted out with Cubase and Pro Tools computer systems, keyboards, bespoke touchscreen control surfaces and quad monitoring systems with modified Quested VS210 speakerss for front L and R and Dynaudio BM5 MkII speakers for the rear L and R. Conversion to full 5.1 surround is apparently handled at a later stage in the production process.

Both rooms were initially set up with the speakers firing across the short axis of the room, the front speakers being placed in front of the outside wall, which featured a large window with plastic venetian blinds. Usually, it is better to work along the longer axis of the room as this reduces the chances of ending up sitting in a bass null zone, but it was not practical to turn Hans' room around, partly because the cables to the machine room wouldn't allow it, but also because he'd set it up this way so that a sofa could be placed along the longer wall behind him, to accommodate visiting producers and others working on the project. Turning the room around wouldn't have allowed the rear sofa, because of the positions of the room's three access doors. We did, though, manage to re‑orientate Lorne's production room, which worked very well.

Room For Improvement

In order to get the tweeters roughly at head height, Hans' Quested monitors had been laid on their sides. However, this was compromising the size of the monitoring sweet-spot, so they were eventually turned upside‑down.

In Hans' room, the existing setup comprised a large table to hold three monitor screens, and also to support a pair of shortened speaker stands holding up the Questeds, which Hans had arranged on their sides to give him plenty of stereo width, and to bring the tweeters down more into line with where he needed them. A Doepfer weighted keyboard was pushed up against the front edge of the table, and there was another small desk to the right supporting yet another monitor, showing the Pro Tools channels used to bring sampler outputs into the system. Hans uses a hybrid system, composing on Cubase but using Pro Tools as a way to monitor the sampler inputs, and also as a means to record them as individual audio files for the final mix, which would be done using a Euphonix Series 5 console.

The equipment racks in the central machine room generated a huge amount of heat, so extra air conditioning had been rigged. However, some noise from the air conditioning and computer fans also leaked around the edges of the adjoining door into the room Hans was using. We did recommend ways of improving the seal around the door to help reduce the noise, and Tom was considering hanging one of the heavy black drapes in front of the door as an easy and non‑invasive, quick‑fix solution. If you have visions of Hans sitting in a comfortable hotel suite writing epics on his laptop while sipping endless Martinis, they are quite some way from the reality!

Making Plans For Hans

Paul hanging one of his wooden frames. Curving the foam out so that it protruded from the wall, rather than simply hanging flat against it, made it more effective at absorbing lower frequencies.

Our initial assessment was done alongside Tom Broderick, as he looks after many of the technical aspects of Hans' setup. He fully appreciated that the low end would behave in a more consistent way if the speakers were firing down the length of the room, but the need to accommodate visitors precluded this. Considering the room dimensions, both Hugh and I were concerned that Hans would end up sitting very close to the centre of the room. Given the small size and fairly solid walls, this would probably result in a significant bass null at the listening position. Tom put up some commercial recordings so we could check our theory and, sure enough, there was a huge hole in the bottom end right about where Hans' chair would be. We were also a little concerned that using the monitors on their sides would restrict the width of the sweet spot unnecessarily, but we could also see that setting them up normally would place the tweeter too high, as the stands needed to be tall enough to clear the large monitor screens Hans was using.

Leaning forwards or backwards by around 18 inches was enough to get the listening position clear of the dead spot, so we asked Tom if we could claw back a little space by taking down the blackout curtain over the window, then moving the table towards that wall as far as it would go, which gave us around 12 inches of extra space. As the window was fitted with blinds, we didn't think window reflections would pose a significant problem. We also asked about the possibility of either adding height to the table or lowering the keyboard stand by and inch or so. This would enable us to slide the back of the keyboard underneath the table edge, which would give us the extra six inches we needed. Tom thought this sounded like a good plan and said he'd have it done by the time we returned to finish the job. I also suggested we simply turn the monitors upside down so the tweeters would be at the bottom, as that would get them closer to the ideal height without compromising the width of the sweet spot. Again, Tom thought this was a practical move as long as Hans was happy to do it.

With Tom Broderick's help, one last piece of foam was stuck to the ceiling, at the mirror point above Hans' listening position.At our proposed new listening position, the bass end was surprisingly even, possibly due in part to the bass‑trapping effect of the window. All we needed to do to make the space acceptably workable was to put in some mid/high absorption at appropriate points in the room. We couldn't stick anything directly to the walls, and we preferred not to drill holes if we could get away with not doing that, but luck was on our side, as an aluminium channel had already been fitted to the rear and side walls for supporting notice boards. All we needed to do was devise a hanging system that would utilise the slot along the top of the aluminium channel. Our first thought was the old 'CD‑R stuck to the back of the foam' trick, as the lower edge of the CD‑R would drop neatly into the slot. However, as Tom's own Universal Acoustics panels and our newly supplied Auralex foam panels were fairly thin (and therefore would only really absorb at relatively high frequencies), we felt it might be better if we could find a way to create some air space behind the panels to make them more effective in the lower mid-range.

Zimmer Frames

Hans' suite, after the improvements were made. In addition to treating the walls, the setup was pushed closer to the wall to avoid the central room node, thus providing a smoother bass response.

After some experimentation, I came up with the idea of a lightweight wooden frame that we could glue to the foam panels only at their ends, and position them so that the foam would bend outwards from the panel in a curve. With two foam panels per frame, this would produce a wave‑like visual effect with around six inches of space behind the centre of each panel. We figured that two of these frames on each side of the room at the mirror points, with two more behind the listening position, would be enough to tame the room ambience and to allow us to dispense with the rather oppressive blackout curtains.

It was around this point that Hans arrived, so we discussed our findings with him and he seemed generally amenable to our proposed changes. He even thought inverting the speakers was a good idea. He wasn't worried about the room being acoustically perfect — he told us he was used to working in imperfect rooms and could compensate for most things, but any improvement would be welcome. When I asked him why he'd left his home facility to work in what must have seemed like a broom cupboard to him, he said it was better than last time he'd worked at De Lane Lea, when he'd had to use a tiny room in the basement to put together the music for the Wallace & Gromit: Curse Of The Ware Rabbit movie! As the rest of the movie sound for the current project was being done at De Lane Lea, it made more sense to be on site, especially with such a tight deadline.

Back Down De Lane

A few days later (at the same time as the London riots, as it happens!), we returned by train, along with a bag of tools, a couple of canisters of spray adhesive, a packet of hob nobs, and six wooden frames that I'd knocked up in my basement. Rather than risk the frames on the underground, we took a cab to the studio, whereupon Tom gave us access to the outside roof area, where we could do our gluing without gassing the staff! True to his word, he'd also managed to move the table and keyboard, and to invert the monitors.

Once we'd stuck the foam to the frames, we simply put a couple of short wood-screws into the back of each and then hung the protruding screw heads in the slotted aluminium channel on the walls. When we had completed the constructions and hung them in the room, we felt that a little more absorption was called for, and as we had some leftover foam panels, we glued pairs together along one edge, with cardboard strips stuck over the rear of the joins for reinforcement. These were hung flat against the wall between our curved panels on the rear and right‑hand side wall, to increase the area of absorption. One further panel was stuck to the ceiling above the listening position, using the minimum possible amount of adhesive (Tom said we could get away with that!), and another hung on the left‑hand door using a discarded CD‑R and an existing picture hook.

Lorne had managed to configure his suite such that the speakers were pointing down the room's longest dimension. Again, foam tiles were hung on the walls to minimise early reflections, and we suggested that he truncate his speaker stands so that the monitors could be more ideally positioned, as Hans had done in his own room.With the blackout curtain in place, the rooms had looked and sounded a little claustrophobic, as the relatively thin material from which they are made is most effective only at higher frequencies, throwing the mids and highs somewhat out of balance. Switching to the foam and leaving more bare wall exposed meant that the room acoustic felt better balanced, with a bit more air at the high end — dry enough to be workable but not so dry as to sound oppressive. The changes to the furniture position and the monitor orientation had smoothed out the low end to a useful degree, and Tom said he'd hang some blackout curtain over the machine-room door to try to reduce the noise leakage from that source. Hans seemed very satisfied with the outcome, as the room not only behaved better, but also gave him a little more space in which to work. I think he was a bit worried about being able to see daylight, though!

Room Two

Lorne Balfe, Hans Zimmer's co‑composer for the second Sherlock Holmes film.

That left Lorne Balfe's room to deal with, but, fortunately for us, Tom had moved Lorne's system around after our first visit, so that the speakers were now pointing down the long axis of the room, and they'd already hung blackout curtain on what was now the rear wall. We moved a table and bookcase at the rear of the room to provide more space, and this time left the blackout curtains in place over the rear wall and also over the window to Lorne's left. There was a patchbay and wiring frame on the right wall, right at the mirror point, but as this wasn't being used, we decided to stick a panel of foam over it (using Gaffa tape and a couple of small patches of glue) and to fix two more above and below it. We'd moved the bookshelf so that it was now directly behind the patchbay, so we used that to support a couple more foam panels. We couldn't carry enough frames to do both rooms, so for Lorne's room we simply used flat panels hanging against the walls.

We found another of those useful aluminium rails running along the wall behind the front speakers, so we were able to hang four widths of foam from that, each being made from two panels glued together along one edge and again supported with cardboard bracing on the back, to reduce reflections from the bare wall and to help dry up the overall room ambience. We simply used old CD‑Rs stuck to the back of each panel for hanging them, and these slotted perfectly into the rail. Accepting that this was a quick and dirty solution, and that the panels would need to be taken down again once the project was completed, we asked Lorne to evaluate the improvements. To our relief, he said the sound felt noticeably tighter than before, and now that he was monitoring along the length of the room rather than across it, he felt more comfortable with the sound generally.

In this room, the front Quested speakers were mounted on full‑height stands that had to be placed to the sides of the desk, and that made them slightly wider spaced than was ideal and, more importantly, resulted in the tweeters being partially obscured by the monitor screens. In Hans' room, the same tall speaker stands had been cut to length and placed on the table, so Tom said he'd see to that after we left and adapt them to support the speakers tweeters-down, so that they were closer together behind the monitors and high enough for the tweeters not to be obscured. This is what he'd done in the room Hans was using, and it had proven to work fine.

By now, the aroma from the neighbouring Red Fort Indian restaurant was proving to be too seductive, so we left Hans and Lorne to get to work on their film score while we perused the lunch menu!