Fritz: Studio Designer and Acoustics Expert

Fritz from Unit 11 studio design has been designing and building recording studios, both professional and amateur for about 20 years and has become an expert in all aspects of soundproofing and internal room acoustics. Fritz is an extremely intelligent guy who approaches each project as a personal vision. He works on every aspect of each job himself, from designing to building to choosing the décor and is reluctant to delegate anything in case the quality of the results should be compromised. SOUNDSCENE interviews Fritz over a pint at his local pub in north London after a hard days work on his latest commission; a studio at Westminster University.

SOUNDSCENE: What led you to become an expert in this field?

FRITZ: As a teenager in New Zealand I was playing in bands and couldn’t afford to go into a recording studio so I built my own! And then I became interested in the physics of it. The science of sound is fascinating, all about waves and nodes and interference patterns.

SOUNDSCENE: Did you need to learn any specific skills?

FRITZ: Yes, I had some training in building skills which is an advantage otherwise you have to employ someone else to do it for you and there’s certain aspects of soundproofing where you really need to know what you’re doing. It’s no good simply chucking stuff on the walls; you have to think about the structure.

SOUNDSCENE: What’s the best way to soundproof a room?

FRITZ: With soundproofing, you can either build a massive structure which is very expensive and impractical or you can use the ‘room within a room’ technique which is sort of opposite to what most builders are used to doing; they want to make things rigid and structurally sound but the idea of a ‘room within a room’ is that soundproofing is achieved because there is no physical or mechanical connection between the inner and outer rooms. You have to ‘float’ the floor on insulating materials and then work upwards.
Air is the best thing for sound insulation… the bigger the cavity between the external and internal rooms the better. You need a minimum gap of at least 2 inches otherwise the trapped air in the cavity effectively becomes solid, so you get the mechanical transmission of sound. When floating doors and walls, high-density rock wool is ok or there are other products available like neoprene and rubber balls and different types of suspension but it’s so expensive that the client would be better off moving to the countryside with no neighbours and no need for soundproofing!
In London or any big city, people are living like colonies of ants stacked up above each other, which is why I constantly get work soundproofing. If you have the luxury of space then all you have to worry about is the acoustic side of things.

SOUNDSCENE: It sounds like there’s a lot of demand for your services

FRITZ: Yes. I’ve done some work building studios for big companies like Sanctuary and Warners but what with modern recording techniques, computer hard disc recording etc and the cheapness of everything I’m more in demand by private individuals wanting to build a home studio set up. You can get all the equipment for a professional sounding studio for very little money now which is why lots of big expensive recording studios are going bust or closing down. In a way it’s a crying
shame because the quality of the rooms was much better, they had well designed live rooms and the control room was big enough to get good acoustics.

SOUNDSCENE: Is it possible to get good results in a home studio?

FRITZ: In your average spare room, which is, say 11ft square, there is something called a standing wave whereby the physical size of the room relates to the wavelength of the sound that the room resonates at, in the same way that an organ pipe resonates at a certain frequency depending on its length.
With a smaller room, assuming it is soundproofed, the walls will reflect most of the sound energy back into the room and you end up with a situation where if you play a low note, there are areas where you can’t hear it and areas where it’s really booming.
The room needs to be large enough to conform to certain ratios; Bolt’s ratio (like the Golden Ratio in geometry) whereby the height isn’t a multiple of the depth, which isn’t a multiple of the length of a room. Basically, if your room is a cube, that will suck!
It’s a bit of a fallacy about having weird angles or splayed walls because all that does is skew the standing wave in an unpredictable way. A random oblong or L-shaped room can work best because at least that is predictable and you can design in acoustic treatments to accommodate those predictable problems.

SOUNDSCENE: Are there many people in your field doing the same job as you?

FRITZ: No, there’s hardly any. There’s a bunch of main companies who do larger venues, famous companies that have been going for years like Monroe, AKA, Recording Architecture but there’s very few who caters to the smaller market, i.e. Programming suites and home studios. Those jobs aren’t profitable enough for the big companies… the most I’ve had as a budget for a domestic job is in the region of £30,000.

SOUNDSCENE: What advice could you give someone wanting to build their own studio?

FRITZ: One important thing to consider right from the very beginning is air conditioning or a fresh air supply. If you build a soundproofed room, you’re building a really good oven! Sound insulation provides heat insulation as well so it’s a big concern. Air conditioning can be very expensive so you need to include extra costs in your budget for it. Also you will need to consider the fact that air conditioning can make noise and account for that.

SOUNDSCENE: If someone wants to build their own studio in a bedroom or garage, how much would it be likely to cost?

FRITZ: That’s very hard to say because it depends entirely on the amount of acoustic and soundproofing problems they are going to encounter. Also there are degrees of how far you can take the whole thing.
If you want to build a basic room within a room of around 10ft by 16ft using a fairly lightweight shell with 2 or 3 sheets of plasterboard, with high density rock wool as insulation, doors that are properly sealed and windows that are correctly glazed, all the materials you need to use can be bought from your local builder’s yard for between £3000 and £4000 but then you need to build it yourself or allow for labour costs on top.
When I take on a job my price can vary enormously because all the problems relating to ‘will it be properly soundproofed and is it going to sound good’ vary so dramatically.
Recently I designed and built a room for a band with a large PA system and drum kit that was on the other side of a wall about 4 ft away from where someone had to sleep and couldn’t be disturbed which was a challenge! We used about 8 tonnes of materials for a 4m X 5m room. If someone says they want absolute silence outside the structure, you get diminishing returns; The basic soundproofing cost around £5000 but we had to spend another £10,000 just to eliminate that last little bit of extraneous noise. You can get quite good results reasonably easily but getting total silence is very difficult as sound is such a pervasive medium. Think of it this way… if you lie awake in the dead of night when everything’s completely silent, you can hear a sparrow fart in Hackney!

SOUNDSCENE: Can you explain how to get the right acoustics for a control room and live room?

FRITZ: You mustn’t confuse the soundproofing with the room acoustics. Internal room acoustics is treating a room to make it sound the way you want it to sound… for a control room that would normally be ‘flat’ with no big lumps or peaks as far as the EQ is concerned. That is to say, if you record with a microphone in a live room, the thing you are recording is the exact thing coming out of the control room speakers with no added acoustics.
The ear perceives as natural a sound with a small amount of room reverb, as opposed to a completely dead room with no reflections, known as an anechoic chamber. These were popular in the 70’s; if you walk into an anechoic chamber it’s like stuffing your head into a pillow, which is no good for a control room where you’re monitoring sounds and listening to the mix. To a certain extent the ear relies on some reflections in a room; if you put an amplifier in a field, suddenly you can’t hear anything unless you crank it right up, because there are no reflections.
If you have a glass window in your control room, you need laminated rather than normal glass; normal glass pings if you tap it where as laminated just thuds so it’s less reflective. You also need to angle the glass away from you so the high frequency reflection doesn’t bounce straight back in your face!
When building a control room, the ratios I mentioned earlier are the most important thing. Then you need to suspend bass traps from the walls or ceilings to take out any harsh frequency reflections… you can buy stuff off the internet like ‘Studio in a Box’, products that use things like foam or Oralex, a whole plethora of stuff you can buy off the shelf and stick on the wall with Velcro and it will do mid-range to high frequency attenuation on the room. It’s the same if you hang duvets on the wall… or the old favourite, egg boxes! The cheapest, most effective method I have found is to use Rock wool covered with fabric. Don’t confuse any of these acoustic treatments with soundproofing… they’ll do little to stop the neighbours complaining!
Something that’s become increasingly popular is RPG systems. Basically it involves attaching slotted boxes to the walls, which resemble bookcases. The theory is based on thinking of sound as being like a ray of light, and the boxes radiate the wave in a diffuse pattern, like if a mirror is covered in dew, you can still see reflections or patterns when you stand to the side of the mirror, not just directly in front of it. The effect sonically is of diffusing or ‘smearing’ the sound across the bandwidth. You can buy these off the shelf and they do have some merit. In a small room they can make it seem as though the walls are further away than they are.

When it comes to recording, making a good live sound requires a more artistic interpretation of a room, and to some extent it’s a question of taste. For a live room where you do want natural reverb, you need to think about the materials you use for the surfaces of the walls as the absorption coefficient determines what frequencies will be bounced back. Some people love the sound of bathrooms because the shiny surface of the tiles reflects all the frequencies back into the room.
Personally I like the sound of good quality wood floors with some carpet to take out the harsher top-end frequencies. On the walls, tongue and groove panelling can sound really good; the small grooves in the wood resonate in a pleasing way because it’s an irregular, chaotic surface.
For a drum booth, you need character and flavour. A hard irregular surface like slate tiles or concrete is good with areas of absorption like fabric or carpet panels to control high frequency reflections.
For recording vocals you do need a very dead room or anechoic chamber so that you can control and add your own reverbs afterwards.

SOUNDSCENE: If someone wanted a career designing and building studios, what’s the best route to follow? Are there any courses available?

FRITZ: As far as I know there are no real courses for the structural side of it; Guildford University does a course in Applied Acoustics which teaches some of the scientific and mathematical principles involved, but I don’t know of anywhere that specialises in the musical side of acoustics. There are some good books that you can use to teach yourself; How to build a Recording Studio by Paul White is a good place to start. Try looking at Studiospares.co.uk or in music shops. Obviously some building experience is useful but other than that you just need a feel for the subject and an interest in sound.
Go into a room and put a sine wave on your stereo, then walk around and listen, use your ears and you should be able to hear the nodes or peaks and troughs of the sound waves as you walk around. Then you’ll know where in your room the sound is ‘true’ and where it’s being corrupted by reflections. You can also buy room analyser kits, which you plug in to your system and they will work out how your room is behaving, but they won’t tell you how to fix it… that’s where I come in!