studio design guide

7/23/2019 Studio Design Guide

1/24

The Recording Studio Setup and Design Guide

James Koblick


2/24

Introduction:........................................................................................................................ 3

A Recording Studio vs. A Booth ....................................................................................... 4

Building a Home Recording Studio.................................................................................... 5

Acoustics............................................................................................................................. 5

Diffusors and Absorbers ..................................................................................................... 7

Bass Traps........................................................................................................................... 9

Fiberglass Bass Traps ....................................................................................................... 11

Room Design and Layout ................................................................................................. 13

Reverberation Time of a Room......................................................................................... 15

Studio Furniture ................................................................................................................ 18

Symmetry in the Studio .................................................................................................... 19

Soffit Mounting................................................................................................................. 20

Hard or Soft Materials ...................................................................................................... 20

Reducing Noise................................................................................................................. 22

Summary........................................................................................................................... 23


3/24

The advancement of technology in the sound industry has done two things for audio

enthusiasts; increased the quality of equipment and decreased the cost to get that equipment!

What this means is setting up and designing home studios is a very real possibility one that

could not have even been conceived 15 or 20 years ago!

Oftentimes, home studios are nothing more than a mixing board, a mic, an inexpensive

computer, and so on. Not much attention is paid to sound deadening, wall construction, room

width and height, and other very vital pieces of the mix. It is just somewhere that a person can

record their work, mix it, burn it, and distribute it.

But what if you want something more? What if you live on a busy street and your

studios window is right on top of it? How can you combat the occasional Harley Davidson with

the exhaust that rattles your dinnerware? Or a 5 year old looking for popcorn to eat while

watching a movie? These things can be a significant burden if you are trying to finish an audio

track that needs to be in your clients office by the end of the day!

There are other concerns as well: helicopters, airplanes, garbage trucks, neighbors, air

conditioning, heater vents, and even computer fans. What ultimately happens is all of those

seemingly inconsequential noises adds up to too many takes, and slows the recording process

down to a snails pace.


4/24

There are a couple of options one might pursue if the outside distractions are too much to

handle; and we are going to be covering them in depth here. For instance, you might be looking

to set up a full out studio, complete with all of your gear, sound deadening, bass traps, and so on.

If you have the money and the time to spend, this is a fantastic option.

On the other hand, maybe you are just looking for a booth, with a door that you can shut

to keep the kids away. You might just be looking for a computer and a mic with a mixing board,

and thats about it.

Depending on your budget, and your homes layout, anything is possible. In this

document, we show you some tricks of the trade, and give you tips on how to design the best

recording studio for you!

One of the biggest questions you need to ask yourself is how much room do you have? Is

it possible to build a structure 4 foot wide by 4 foot long by 6.5 fot tall in your office? Do you

have the much space in the corner?

A booth is oftentimes the most

affordable solution when in a tight area.

Another major benefit is it can be moved

if required! So if you live in an

apartment and cant put holes in the

walls, a sound booth, or an isolation


5/24

area, is your best bet! Not to mention, it is easier to seal walls and soundproof a new structure,

than an existing one.

A recording studio, on the other hand, is a much greater task. Not only do you

need to take the room dimensions into account, you need to be wary of windows, heating and air

conditioning vents, neighbors, and everything else associated with soundproofing an existing

structure! Plus, its not quite as easy to move the custom fabricated baffles and material.

Truthfully, the rest of the information in this eBook applies to both recording

studios and booths. Each has to be constructed similarly in regards to noise cancellation and

materials. The only difference is booths require less of it!

When building a home recording studio, there are a number of things to keep in

mind. There is the Golden Section, which is a set of ratios that keeps sound in a room or in a

structure very, very even. There is the equipment and ventilation. Keeping the decibels down of

your peripheral equipment is a necessity - and so much.

We are going to be getting into some of the major considerations in building a

studio in the following sections.

There are basically four goals in acoustic treatment; and they all exist so your music

doesnt disturb the neighbors, and so your neighbors dont disturb you!


6/24

To prevent standing waves and interference from affecting the frequency response of

recording studios and listening rooms.

To reduce modal ringing in small rooms and lower the reverb time in larger studios,

auditoriums, etc.

To absorb or diffuse sound in the room to avoid running and flutter echoes, and improve

imaging.

To keep sound from leaking into or out of the room.

So why is all this stuff important? Well if you spend thousands of dollars on the very

best equipment out there, and dont do anything with the acoustics of your room the result is as

much as a 30 dB drop in response. So why even spend the money in the first place?

Not only that, but when you are recording or mixing in an acoustically accurate

environment, you are able to produce sound in its truest form. Then, when you sell your music

or someone else is listening to it, discrepancies in their own rooms arent exaggerated.

For example, if your studio has a hole in the

lower frequencies, you might add too much deep

bass, so that it sounds right to you. Then, a listener

plays your music in his room, which exaggerates

bass the result being way, way too much bass!

There are basically two types of acoustic

treatment absorbers and diffusers. Then, within


7/24

absorbers, one type controls midrange and high frequency reflections, while the other is used for

lower frequencies and is known as the bass trap. Also, one type of diffuser is a deflector!

Confused yet?

Oftentimes, you see home recording studios that cover the walls in blankets or foam to

cancel out any echo. The problem is - thin treatments dont do anything with low frequency

reflections. If the owner claps, they might not hear an echo, but if they hook up their bass, the

reverb will be terrible! Sometimes the most effective method when working in a basement or

garage with brick walls is to simply install a wall of sheet rocks a couple inches in from the

concrete!

Diffusors:

Diffusors do what their name implies diffuse frequencies. Diffusors are used to reduce

or eliminate repetitive echoes that occur in rooms having parallel walls and a flat ceiling. One

type of diffuser is called a defector. A deflector is nothing more than angling the walls up or

down so that no two walls can bounce sound off of each other. In other words, an angled wall

will throuw the sound into the carpet or towards the ceiling, rather than right back and an

adjacent wall.

Another choice is the install a curved deflector. A curved deflector is nothing more than

a piece of wood that is bent or bowed, so that it bounces sound to all three walls rather than the

one directly opposite it. The once catch install insulation between the wall and the bowed


8/24

plywood. That way the empty space in between doesnt have an opportunity to resonate to its

own frequency.

Diffusors, however, use an irregular surface with a complex pattern to scatter the sound

waves even more thoroughly. An example being a chamber or box, with recesses built at

different depths. True diffusers scatter sound waves in different directions based on their

frequency, rather than merely redirecting all waves in the same direction. Real diffusers avoid

direct reflections altogether, and offer a more open, natural sound than a simple flat or curved

surface.

Another benefit of true diffusers is that they reduce sound leakage between instruments

being recorded at the same time. Where an angled wall simply deflects sound, a diffuser scatters

the sound over a much wider range. So whatever arrives at the wrong microphone is greatly

reduced in level because only a small part of the original sound arrived there. The rest was

scattered to other parts of the room.

Absorbers:

You can imagine what an absorber is it absorbs sound! Why would you want

something to absorb the sound you worked so hard to create? So it doesnt reflect against walls

and otherwise distort you music!

The most effective absorber for midrange and high frequencies is rigid fiberglass -

examples being Owens-Corning 703 and 705, or equivalents from other manufacturers. These

materials are what professional studio designers use and they are what we recommend for you

as well. You can use more traditional acoustic foam as well, but oftentimes the effectiveness of

the material is less than you might expect.


9/24

Not only are these types of rigid fiberglass fantastic acoustic absorbers, but they are also

fireproof and can retard the spread of heat. They are often available in panels of two by four feet

with thicknesses ranging from one to 4 inches. Custom sizes may be ordered as well, for that

tricky job you have been commissioned to do!

Also, the general rule of thumb is the thicker the fiberglass, the lower frequency it can

absorb. And even through 703 and 705 fiberglass panels are more effective than foam of the

same thickness; they are usually covered with fabric for appearance, and to prevent the glass

fibers from escaping into the air. Unfortunately, this adds to the expense and difficulty of

installing the panels, though.

When installing fiberglass, take care to wear work gloves and a facemask. The fibers

themselves can be pretty troublesome. Usually, the proper way to mount rigid fiberglass to a

wall is with sheet rock screws and large diameter washers with a small hole. The washers help

prevent the screws from pulling through the material. You can also use liquid nails if you prefer

not drilling though the wall. Once the fiberglass is attached to the wall, you can build a wooden

frame and cover it with a piece of porous fabric. Then put it up in front of the fiberglass on your

wall!

The most common reason for installing bass traps in recording studios and control rooms

is to minimize standing waves and acoustic interference which skew the rooms low frequency

response. Acoustic interference occurs inside a room when sound waves bounce off the floor,

wall, and ceiling, and collide with each other; as well as the waves still coming from the speaker.


10/24

If you dont treat the interference, it can create severe peaks and dips in the frequency response

that change as you move around in the room.

The only way to get rid of these peaks and dips is to reduce the reflections that cause

them. This is done by applying treatment that absorbs low frequencies to the corners, walls, and

other surfaces so that sound doesnt reflect back to the center of the room. A device that absorbs

low frequencies is called a bass trap. Although it may seem counter-intuitive, adding bass traps

to a room usually increases the amount of low frequency produced by loudspeakers and musical

instruments. When the cancellations caused by reflections are reduced, the most noticeable effect

is increasing the bass level and making the low frequency response more apparent.

A very common misconception one I want to warn you about - is that small rooms

cannot reproduce very low frequencies, so they're not worth treating at all. A popular theory is

that very low frequencies require a certain minimum room dimension to "develop," and so can

never be present at all in smaller rooms. I thought this toward the beginning of my career! The

truth is that any room can reproduce very low frequencies, as long as the reflections that cause

acoustic cancellations are avoided. When you add bass trapping, you are making the walls less

reflective at low frequencies, so sound that hits a wall or ceiling will be absorbed instead of

reflected. The net result is exactly the same as if the wall was not there at all - or as if the wall

was very far away - whatever does come back is greatly attenuated due to distance and,

therefore, not loud enough to cause as much cancellation.

Also, some people mix using headphones in an attempt to avoid the effects of their room.

The problem with headphones is that everything sounds tooclear and present, making it difficult

to find the ideal volume for some tracks. When listening through headphones, a lead vocal or


11/24

solo instrument can be heard very clearly, even if it is quiet, so you'll tend to make it lower in the

mix than it should be. Likewise, it's difficult to assess the amount of reverb and echo being added

electronically when using headphones.

Fiberglass bass traps are among the simplest and least expensive to and install. Studios on

a tight budget can apply rigid fiberglass in the room corners and lose only the small amount of

space in the corners. Since bass builds up the most in the corners of a room, this is an ideal

location for any bass trap. When installing the fiberglass in a corner, the large air gap in between

the sheet and the wall help it absorb these low frequencies.

Another location you might think to install a similar type of bass trap is the ceiling

corners; where the ceiling connects to the wall. You apply the fiberglass in the same way

attaching it with wood strips that are

screwed to the wall.

Another great and

inexpensive way to make a bass trap

- if you have a lot of room - is to

place bales of rolled up fluffy

fiberglass in the room corners. These

bales are not expensive, and they can

be stacked to fill very large spaces.

Better still, they are commonly available and you don't even have to unpack them! Just leave the


12/24

bales rolled up in their original plastic wrappers, and stuff them in and near the room corners

wherever they'll fit. Stack them all the way up to the ceiling for the most absorption.

There is another type of bass trap known as the Helmholtz resonator. Unlike foam,

fiberglass, and tubes fitted with fiberglass, a Helmholtz resonator can be designed to absorb very

low frequencies. This type of trap works on the principle of a tuned cavity the downside being

it is often only efficient over a narrow range of frequencies. The range can be widened by filling

the cavity with fiberglass, or by creating several openings having different sizes. One common

design uses a box filled with fiberglass with its front opening partially covered by a series of thin

wood boards separated by air spaces. This is called a slat resonator. Another also uses a box

filled with fiberglass but has a cover made of pegboard containing many small holes. While it

can be sized to absorb the dominant frequencies in a particular room, it cannot absorb all the

other low frequencies. And broadband absorption or bass traps put up in the corners - is needed

to prevent acoustic interference that skews the frequency response throughout the entire bass

range.

There is also a bass trap known as the membrane absorber, also called a panel trap. It is

made with a wood front panel; one advantage of membrane traps is that they do not have to be

very thick to absorb very low frequencies. Because the bass range spans about four octaves, most

panel traps are designed to work over only part of the bass range. Therefore, you will need an

equal mix of trap types, with one intended to absorb the lower bass frequencies and the other for

the higher bass range. Besides absorbing low frequencies very well, the wood front on a panel

trap is reflective at higher frequencies. So installing enough of them to treat a room properly for

low frequency problems will not make the room too dead sounding at mid and high frequencies.


13/24

Oftentimes, you cant build a room to use as a studio. You are stuck with an area in the

basement or a spare bedroom that will act as your studio. It is true that if you were designing the

room yourself, you would be more inclined to calculate the width, height, and length of it

yourself, and build it to exact specifications. But instead, you are stuck with what you have

given to you.

There are slightly complex calculations involving room modes, and these are ideal if you

are building the room yourself. Otherwise, you have little control over the size and space you

are allotted.

Basically, every rectangular room has three room modes the height, the width, and the

length. Generally speaking, larger rooms are better acoustically than smaller rooms because the

modes are spaced more closely, yielding an overall flatter response. Acoustics experts

recommend a minimum volume of 2500 cubic feet for any room in which high quality music

reproduction is intended. This, however, is outside the scope of this project!

One important factor I want to touch on in the design of home studios and listening

rooms is the ratio between the length, width, and height. The worst shape possible is a cube

having all three dimensions the same. A cube has the fewest number of peaks, and therefore the

greatest distance between peaks, because all three dimensions resonate at the same frequencies.

An ideal room would have each dimension being different, which will contribute peaks at

different frequencies, thus creating more peaks having a small distance between them.


14/24

There are several simple ratios that experts agree produce supreme audio quality three

of them developed by L.W. Sepmeyer. Here are the findings:

Height Width Length

1.00 1.14 1.39

1.00 1.28 1.54

1.00 1.60 2.33

Basically, what that means is if you have a height of 8 feet, the width needs to be 9.12

feet (8.00 x 1.14), and the length needs to be 11.12 (8.00 x 1.39). Even if you cant achieve

those exact specifications, the closer the better!

Also of interest is the Golden Ratio, which has been used in mathematics and arts for

centuries. The Golden Section, which is derived from the Golden Ratio, is a set of ratios

originally developed by the

ancient Greeks, which can be

used to design sound rooms.

The ratio has the smallest

dimension (often the height)

as the starting point, and the

nest longest dimension being

1.62 times that length. The

final dimension should be 1.62 times the second dimension. When a room is built to these

specifications, the sound is incredibly even!

Also of note, there are many freeware and web based room mode calculators. These can

be used to determine if the shape and dimensions of your room will resonate well. The one


15/24

application that is missing, though; is something that makes recommendations as to tried and true

techniques to soundproof the room! So if anyone out there is a programmer, by all means save

us a lot of trouble

As you can see, there are a number of different ways a studio can be built and used. The

bottom line is, What do you have to work with? If your room falls in between these scales, to

one degree or another, you can utilize bass traps and other soundproofing options to achieve the

perfect response for your particular type of music.

While we are on the topic of room design, it is worthwhile to take a minute and talk about

reverberation of a room or in actuality, calculate the reverberation time.

Reverberation depends on the volume of the room and the rate at which the sound energy

is absorbed by the wall surfaces and the objects in the room. The reverberation time in a bare

room is proportional to the ratio of volume to surface. In other words, the reverberation time is

the time required for the sound level to decrease by 60 dB. In 1922 a pioneer in the study or

room acoustics, Wallace Sabine, came up with a formula:

RT60 = k(V/Sa)

k is a constant that equals 0.161 when the units of measurement are expressed in

meters and 0.049 when units are expressed in feet.

Sa is the total surface absorption of a room expressed in sabins. It is a sum of all

the surface areas in the room multiplied by their respective absorption


16/24

coefficients. The absorption coefficients express the absorption factor of materials

at given frequencies.

V is the volume of the room.

For the calculator itself, please visit:

http://www.saecollege.de/reference_material/pages/Reverberation%20Time%20Calculator.htm

So what exactly can you work out with this calculator?

Let's start with a room with the following dimensions.

Length 6 meters

Width 5 meters

Height 2.4 meters.

Keep in mind, all the walls and ceiling are in painted concrete and the floor in unpainted

concrete. (i.e. we are going to treat the garage) We are then going to add the typical treatment

(you know, get out the egg cartons, heavy drapes and curtains etc)

1. Carpet on the floor

2.

Heavy drapes on the rear wall

3.

Heavy drapes on the front wall

4. Light drapes (egg cartons) on the side walls

5. Light drapes (egg cartons) on the ceiling.


17/24

The original room has a relatively flat response (Bright Blue), albeit a bit long all over and

especially in the top end, and would sound very bright and live with reverb times around .8 sec.

When the typical treatment is applied we land up with a room that has a long reverb time at

125Hz and short at 4 kHz. Because the high end reverb is shorter people will say the room is

dead but in fact it's not really, it's only dead in the top end and too dead at that. The frequencies

below 500Hz are the real concern.

This is the mistake everyone seems to make. All the treatment added only effects the high

frequencies. You must consider all the frequencies when you treat a room. The shorter

reverberation time in the high end is reasonable at 0.3 sec (around 0.4 -0.5sec is desirable) but

you must take down the low end as well. The reverb time at 125Hz is around 2 sec, at 250 it's

0.92 sec, at 500 it's down to 0.49 sec and it reaches 0.3 sec at 1000Hz and is right down to 0.21

sec at 4 kHz. The low mid and lows need correct treatment. See the low-mid and low frequency

absorber pages.


18/24

As with any profession, furniture plays a crucial part in room design. Studio furniture is

no different. Desks and workstations provide a major benefit to someone working in their own

home, and offer an affordable solution to building your own. Workstations offered by the likes

of www.streetwater.com and www.custom-consoles.comgive you the upmost advantage in

designing your own set, while not having to sacrifice functionality.

Other considerations are equipment side racks, music stands, rack bridges, and monitor

stands. Sometimes, the home

studio professional will simply

build these pieces but it is up

to them which direction they

want to go.

Benefits of building

your own furniture is

sometimes tied to less expense

and customization. Materials are often less expensive, but the downside is the time it could take

you to build something you want. The other consideration is acoustics. If you are building a

large workstation entirely out of wood, keep in mind that it will change the acoustics of the room

you just deadened. That is why sometimes the pipe designs are best suited for home recording

stations


19/24

The other alternative is to deaden you furniture with foam or fiberglass. This is possible

by using the same techniques that are used in soundproofing a wall the only difference being it

will be on the sides and underneath your desk. This is also nice for quieting a loud computer!

Unless you plan to record and mix in mono only, the symmetry of your room and

loudspeaker placement are very important. If both loudspeakers are not situated symmetrically in

a room they will have a different frequency response, and your stereo imaging will not be

balanced. In a room that is longer than it is wide, it's better to place the speakers near the shorter

wall so they fire the long way into the room. This puts you farther from the rear wall where the

low frequency peaks and nulls are most severe.

This also applies to the symmetry of your desk and console. Try to avoid placing your

desk against a corner, because the speakers will produce different frequencies when bouncing off

of the walls behind you. Keep your desk symmetrical in the room, so the distance between the

speakers and the walls are the same in any direction.

Also, keep in mind that your ears should be the same distance from each speaker. While

we are on this track, acoustic treatment - whether absorption or diffusion - should be applied

equally on both sides. In many home studios it is not possible to create a completely symmetrical

arrangement, but you should aim for as close to this ideal as possible. Especially in the critical

front part of the room where the first reflections to reach your ears are those from the side walls,

and from the floor and ceiling if they're not treated with absorbent material.


20/24

One somewhat controversial aspect of room design is soffit mounting the main

loudspeakers. Most home studio owners simply put their speakers on stands, or sit them on the

mixing desk, and leave it at that. But many pro studios prefer to install the speakers into the wall

so the front surface of the speaker cabinet is flush with the wall. There are sound scientific

reasons to use soffit mounting, yet some engineers say it's not necessary or that it gives poorer

results. Those in favor of soffit mounting point out that it reduces reflections called Speaker

Boundary Interference, or SBIR, that cause peaks and dips in the low frequency response. If a

loudspeaker is out in the room away from the wall, low frequencies from the rear of the cabinet

will bounce off the wall behind it and eventually collide with the direct sound coming from the

front of the speaker. (Even though it may not seem obvious, very low frequencies do in fact

leave a speaker cabinet in all directions.) Proponents also claim that soffit mounting improves

stereo imaging by reducing mid and high frequency reflections.

If you've ever seen photos of high-end recording studios in magazines, you probably

noticed that the studio room floors almost always use wood or linoleum. A hard floor gives a

nice ambience when miking drums, guitar amps, and acoustic instruments. Likewise, auditorium

stages and school band rooms always have a reflective floor surface. As mentioned earlier, "live"

in this context refers only to mid and high frequencies.


21/24

If you record in your living room and your spouse refuses to let you remove the carpet,

get a couple 4 x 8 sheets of 1/4-inch plywood to put over the carpet when recording. This will

help you get that ambience that some of the larger studios have.

Control room floors often mix hard and soft elements in their design sometimes they

have carpet or wood floors, but are often a combination of the two. Ceilings in these types of

rooms also vary between fully reflective, fully absorptive, or a mix of surface types. There is no

one correct way to treat every room because different engineers prefer a different amount of

liveness. However, you should never make a room completely dead because that produces a

creepy and unnatural sound. The only time you might consider making a room entirely dead is

when treating a small vocal booth or a verysmall studio or control room - smaller than, say, ten

by ten feet. When a room is very small the reflections are too short to be useful and just make the

room boxy sounding. In that case the best solution is to cover all of the surfaces entirely with

absorbent material and, for a studio room, add any ambience electronically.

In a more typical room, there should be a mix of hard and soft surfaces for the walls, with

no one large area all hard or all soft. I suggest applying absorbent material to the walls using

stripes or a checkerboard pattern to alternate between hard and soft surfaces every two feet or so.

This makes the room uniformly neutral everywhere. You can make the spacing between

absorbent stripes or squares larger or smaller to control the overall amount of liveness. If you are

using 705-FRK rigid fiberglass or an equivalent product, you can cover more of the wall and still

control the liveness by alternating the direction of the paper backing. That is, one piece of

fiberglass will have the paper facing the wall to expose the more absorbent fiberglass, and the

next piece will have the paper facing out to reflect the mid and high frequencies. In fact, when


22/24

the paper is facing into the room the lower frequencies are absorbed even better than when it is

faces the wall.

Noise control is one of the most important things you can do once your studio is in the

process. Think about motorcycles going up and down the road, airplanes, the dishwasher,

computer fans, heating and air conditioning vents, and so on. All of these things need to be

alleviated to the best of your ability in order to produce sensational recordings.

In regards to forced air ventilation, make sure the vents are pointed away from the

microphones, or try to adjust the temperature before you start recording. Personally, on a hot

day, I will cool the room down the 5-8 degrees below where I like it and turn the air off. That

way I can work without being distracted.

Another culprit of noise is your computer. Sometimes, the fans are just simply too loud

for the acoustic environment. You can look into low noise power supplies, and components with

heat sinks rather than fans. For instance, my graphics card only has a heat sink, and the

motherboard is lined with them. The processor still has a fan, but it is pretty quiet. It might also

be worthwhile to purchase a case fan adjustor, so you can turn the fans down while recording. A

second option is placing fiberglass below your desk and beside your computer to reduce the

noise further.


23/24

As you can see, there are a number of things that you can do to get a bit more response

out of your home studio. Whether you are building one, planning one, or tweaking one, it is

definitely possible to tweak the acoustics more to your liking.

Also, keep in mind that room symmetry and noise are major components of a good home

studio. So the next time you are contemplating which computer to by, see how much noise it

produces first. Also, take a look at the heating and cooling which can play major factors in a

home studio build.

All in all, have fun with it. It is designed to be your escape, your office, and your

profession. The last thing you want or need is the feeling of having to go and produce music.

There is a lot to consider during the design process, but take your time and be proud of what you

have accomplished.

For Information on Equipment and Processes for your Home Recording Studio,

(The Best Guide you can have in your Studio is here:) Please Click Below )

http://www.Home-Recording-Studio-Guide.Com/4u.html

Thank You,

All the Best In Your Studio!,

Jim


24/24

http://www.Home-Recording-Studio-Guide.Com/4u.html

2007

BIC Books, Inc

Novato, Ca.. 95945

First Printing August. 2007

All rights reserved.

The author and publisher specifically disclaim responsibilityfor any liability, loss, or risk, personal or otherwise, arising

from the use or application of any part of this book.

Cover design by Jason Drohn

For more info on the contents of this book please compose an email

message to [email protected]

studio design guide

Documents