American, Tom Hidley, is probably the most famous name in the world of professional studio design. Over the past twenty-five years his empirical approach to solving acoustic problems has led him to develop various room designs and monitoring systems that have been both innovative and wide-ranging in their influence. Paul Gilby tracked him down at this year's APRS show in London to find out more about the man and his work...

How and where did your career in studio design first start Tom?

"On the acoustic side of things it started in the sixties for me. I had my own studio in Los Angeles and it had all the usual built-in acoustic problems of the sixties. So I began experimenting and drawing on some of the knowledge I had learned when I had worked with JBL at their loudspeaker factory. We worked on aspects like drum leakage spilling over into the string section and reflections off walls which were giving us difficulty.

That period in the early sixties was the transition from Big Band music to the Rock 'n' Roll era. Music was changing very fast, sound pressure levels were increasing and electronic instruments were coming into the studio for the first time. The demands placed upon studio acoustics were changing radically and very quickly."

What was the first studio that you designed?

"It was The Record Plant in Los Angeles. We built that facility in 1969 and it was an experiment with a lot of things - it had wrap-around windows, built-in monitors, traps in the studio and traps at the back of the control room. Prior to that time, most studios were at best covered with acoustic wall tiles and had cement floors - very sterile and awesome buildings. We introduced a lot of new ideas at The Record Plant that have been retained and picked up by a lot of people in the world and have now become commonplace in everyone's studio designs."

After The Record Plant, what did you do?

"I was working full-time for The Record Plant but the owners were good enough to let me do outside designs. Then in 1971 I formed a company called Westlake Audio to market the new-style monitors that were designed originally for The Record Plant project. That company still exists today, but I left back in 1975 and moved to Europe where I opened Eastlake Audio which didn't sell any equipment other than studio monitors. Westlake back in America had a different approach and sold studio design and construction services, and was also a dealer for many manufacturers such as JBL, Crown, 3M etc.

I opened the first Mix Room for Westlake in 1972 and we did a lot of Stevie Wonder's mixing and stuff for the Isley Brothers and Peggy Lee. When I came to Europe I dropped the equipment side of the business other than monitors and specialised in studio design - covering acoustics, construction and monitoring. I then retired from that company in 1979 to get away from the industry for a while."

What brought you back?

"After some years away I was getting pretty restless and in 1982 I started digging into the problem of why studio control rooms had to have graphic equalisers in the monitoring system to make them sound reasonably 'honest'. I discovered four problems in the old design that I felt were detrimental to the room's acoustic performance. Those four problems actually turned out to be the very four elements that meant that the room required equalisation. Hence the new design concept.

A friend of mine in Japan, Shozo Kinoshita, thought he could improve the monitoring, so he took that problem away with him and came back with a solution. The design is new and the monitors are new too, there's no EQ required and there's less ear fatigue in a cleaner, more honest-sounding room."

So what has been your design approach to achieve these results?

"It's largely centred around two areas: one is dealing with the problem of the first reflection from the monitors and getting that under control; the second concerns the studio structure and the way that it's built - how you go about putting the monitors in the wall. These two points are the prime areas that contributed to the monitoring problems of the old rooms.

Along with this new approach came many fringe benefits that happened automatically. For example, in the old studio design, the timber framing system gave a given amount of isolation between control room and studio areas. Now in the new design we surround the monitors in concrete as well as framing, and so suddenly, whilst picking up stability on the monitors, as a spin off you get 15dB better isolation at 40Hz than you had with the previous system.

So, primarily the problem of first reflections and framing motion have now been stabilised and understood, and we've had consistent results so far with five different monitor systems."

The new approach has obviously impressed many people throughout the world. Now that you have come out of retirement, what level of activity are you allowing yourself?

"My work load today is something like about 28 or so rooms to be completed this year - and there's only six months left! We're starting five rooms in Nashville next week and two in Paris."

What is your involvement in a job as the studio designer, do you visit all the sites and progress the work?

"Many times I'll see the site first and other times I won't. Providing the client can supply enough information about the site, there's usually no problem. On designs where there are potential isolation problems, I visit the site and sometimes I have to take isolation measurements plus an analysis of the building structure and its leakage problems, before I get involved with the design.

After the design has been approved by the client the next step is to start the building and provide the labour and materials. We build about 85% of what we design ourselves and the remainder is built by the client; we seldom get into a 'foreman only' situation, it's either all or nothing on the construction side. Due to the nature of construction and the need for supervision, we are only able to have about eight studios on the go at any one time throughout the world. In the case of Nashville, where there are five rooms, it's a big job and we have two foremen out there with a large team of builders."

How do you actually co-ordinate the operation, is it all run from your offices in Switzerland?

"Yes, everything is designed back at the office and the labour comes from three areas in the world. The UK is the prime source, then the USA and Japan. While the crews are out on a job we surround them with local support labour so, for example, the Nashville rooms have about twenty-eight men working on them under the guidance of our two foremen.

When we're constructing a studio in Europe all the materials come from the UK."

Is your approach to studio design still a continuous learning process of room assessment and design adjustment?

"Looking at new approaches is always important. We have one room that is about to be constructed that's going to be a big departure from the conventional studio control room. It's a 'music room' of about 16,000 square feet. In this room will be the musicians and also the mixing desk, producer and engineer - no separate control room, no glass window, everybody will be sitting in the one room...

It's for a major producer who works for MCA Records and it's being designed around his thoughts and desires. It will allow him to have direct communication with the musicians while they're working, because to him this is extremely important - he is at one with the musicians. No more talkback microphone, no more 'boxed-in' feeling. It's like a return to the old musician/conductor relationship."

That design is obviously going to create its own problems when monitoring the music. How are you dealing with that?

"Well the room is, as I said, around 16,000 square feet and in addition there are two other isolation rooms at the far end which will have a massive glass sliding door system that will allow a piano to be rolled out and drums to be set up, or vice versa. A lot of the instruments will be recorded using the direct injection method, as for the drum machine. And probably from what I can ascertain, it will be around 70% electronic and 30% acoustic sound sources. To achieve this they will use the two booths and they'll also have the ability to move from very bright, reflective sound characteristics, with a long natural reverb time, into an area of extremely short reverb time.

What happens from one end of the room to the other is this. Down near the vocal booth end, the room sound is very bright. There are wedged splays that are made of hard wood. There's also low frequency trapping all around the room perimeter, and the ceiling is raked. As you move about two-thirds of the way along the room, the reflective hard wood floor turns to very dense carpet on which the mixing desk is sitting. The walls go from very hard to very soft high density trapping; the ceiling comes out of a hard condition and goes into a V-shape coming down over the monitor area to reach a level of 7'6" off the floor from its original 15 foot height, and it's been built to act as a massive dense sound trap. This will stop the 'open circuit' feedback effect of microphone to monitor pick-up. The transition then goes further back behind the engineer into a very high absorption area with diffusers on the back wall.

Now the monitor situation is very different; on roll-around platforms about four feet high sit a pair of high-powered nearfield monitors. These are surrounded with four inches of concrete so that the side and back radiation of sound normally present with any wooden box structure cannot go anywhere but forwards. Off to the side of the left and right monitors there's also heavy density trapping, and below and in front of the monitors is a lead curtain reaching down to the floor.

With this sort of stabilising, it should mean that most of the energy radiating from the speakers will move towards the engineer and then go beyond him and disappear into the back wall traps. With this sort of environment it means the engineer and producer should be able to work during a recording session as they're in a very different reverb time with high absorption around the mixing area. This is very much a departure from the norm."

Is this studio the first of its type?

"It's the first commercial studio with this design, yes. I've used it in private studios on three other occasions.

If this design proves to give a real musical benefit in the long term, that can be offset with a different approach to recording, then we might not only see the current trend towards larger control rooms continue, but perhaps the elimination of the control room in total - it will become one environment. This is the first commercial attempt and I think it has a very good chance of working well."

Are you working mainly with panel absorbers in this design?

"Yes, panel absorbers for low frequencies that vary from lightweight soundboard to half-inch plywood. The cover density ranges from 1 to 4 inches, depending on what you want to do with it - how much attenuation of the low end you want, how much control of the mid and high frequencies is required."

Have you given this new design approach a name yet?

"Not at the moment, I really haven't thought of one. The studio it's being built in is called Sound Stage."

From what you've said it is very much a new departure. Are you certain the design will work?

"There are a lot of reasons why the room should work acoustically, but if it presents problems I don't think there's anything we can't get over in a different way.

There was a discussion at the design stage which went on for two days with some producers saying that it was never going to work and others saying it's the most exciting idea they have heard.

There will obviously be some things they can't do, like turning their main monitors right up while recording; they will have to adapt to a different working method. The approach to recording will be one where they set up the balance over the main monitors and then whilst recording switch to the very nearfield, small desktop monitors. So, during a session what the producer hears is exactly what the musicians hear, and the detailed balancing is done in the mix later on.

On the mix side of things, the guy it's being designed for wants to use the same room for mixing as well. I thought: OK, I've contained the monitor situation and as it stands you have two solid pillars. Then what we are going to do is have a lead curtain which draws across between the monitor pillars to form a wall for the monitors to work off to give good centre imaging of the stereo sound during the mixing stage. I think that approach will then bring the environment back to a more usual control room behaviour.

I have never spoken about this room design before to anyone. It's going to be interesting to see how it works, because if it's right, it could have a massive impact on the industry in terms of the way people record five or so years from now..."

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