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BUILDING YOUR COTTAGE RECORDING STUDIO

BY ROBERT DENNIS

Editor's Note:

Cottage Industry:

A system of production where workers make or work on products (such as clothes), usually at home, for a merchant or distribution company who pays them for their work.

Cottage Recording Industry:

A system of recording a music production where much of the recording is done in a well-equipped home studio and a larger, better-equipped studio is only used for recording or mixing functions that are beyond the capabilities of the home studio.

The cottage recording studio began appearing in the 1970's where major record producers and recording artists began to install home studios to "try-out" or "start" a production without the cost or pressure of a professional recording studio. Originally this was a "rich-man's activity" with "cheep" 24 track recorders costing $30,000 and decent recording consoles costing $50,000. Today, however, 8 track 20 bit master recorder can be had for less than $2000 and a full-function all-digital console can be purchased for as little as $4000. Thus the "Cottage Recording Industry" is booming.

The cottage recording studio is the premium home recording studio. For anyone interested in home recording, it is the ultimate. We understand that you may not want to make your home recording studio as good as the plans laid out in this article. You will, however, find ideas about studio design that you can apply to any budget.

Now for the article:

The Problem:

Many people have put "home recording studios" in their basement. The basement home recording studio is fun, but has inherent difficulties when trying to use it as a cottage studio, as follows:

1. The ceilings are usually to low to provide the best sound and isolation form the living area of the house.

2. It is difficult to isolate the family activities of (for example) using the kitchen or laundry area, from interfering with the studio operation.

3. It is difficult to isolate traffic from the living area of the house. Many spouses will object to "clients" wandering through the house.

The Solution:

Many houses have an associated building called a "Garage." The garage usually houses the car, the lawn mower, and a bunch of junk. The lawn mower and garden tools/equipment can go into an inexpensive shed next to the garage. The car can be parked in the driveway and the junk can go in the basement. The cottage studio can go in the garage.

With its higher ceilings (usually 8 feet) and large area (usually 24 feet by 20 feet), its peaked roof, and its isolation from the house, it is a much more suitable area for a studio than the basement. Famous professional studios have started in the garage.

Disclaimer

This plan is a guideline that the author feels will provide acceptable results. Before actually starting construction, one must check with local authorities to make sure the construction will meet local building and zoning codes. Permits and licenses may be necessary to legally start construction or use the facility once it is built.

Local, legally-binding, codes vary a great deal from one area to another. Urban areas tend to be more restrictive than rural areas. Because of this, it is also suggested that you get some legal advice from a local attorney. A clerk in a city office may want to put you through more red tape than you legally have to endure. An attorney may help you fill out applications with the least hassle from authorities

Assumptions & Basic Floor Plan:

We are assuming that you have a stand-alone or attached garage that measures 20'x22' with a peaked rood and on a concrete slab. Sizes of garages vary from 20'x20' to 22'x24' which means the basic floor plan may have to be modified slightly to fit your garage size. Surveying a national building supply chain, we found the 20'x22' to be the most common size.

Figure 1 shows how the total area has been subdivided to 5 areas for effective band recording:

Room 1: The Studio area that measures approximately 16'x10' that would be used for the drums and musicians for recording.

Room 2: The Control Room area, measuring 11'4"x7'.

Room 3: A main isolation booth of approximately 5'6"x4" that can be used for guitar or vocals during the session.

Room 4: A 3'x4' closet area for storage of studio equipment and that can be used as a second guitar booth.

Room 5: A 8'6"x8' "Entrance area" that can be used as an office or divided up into storage lockers for tapes and control room supplies. This area can also be an "emergency" isolation room.

This plan assumes you want to be able to record bands with live drums. If you expect your studio to specialize is MIDI work with synthesizers and drum machines, the larger room could be the control room and Room 2 could function as a small studio/large isolation room. You could still do drums in a pinch, but musician eye contact would be harder to achieve. Keeping Room 1 as the Studio will yield a better drum sound.

Room Dimensions:

The first two rooms (Studio and Control Room) are carefully modified from the ancient Golden Section dimensions. A Golden Section is an area that has a specific ratio of height to width to depth. The ratio is approximately 1 (high) by 1.6 (deep) by 2.6 (wide). When a room conforms to these dimensions, it will evenly reflect all frequencies so that any area sounds substantially the same. The ambience in the room will reinforce the tone of the instruments rather that sounding "muddy" or "thin".

In smaller studios, it becomes impossible to strictly maintain the Golden Section dimensions. Often the ceiling would be too low to be practical. If you take one of the surfaces of the room and increase the dimensions (like ceiling height) and you can maintain much of the Golden Section acoustics if you make the surface evenly absorb all frequencies. With this modification, 5 of the six surfaces will evenly reflect the frequencies and the 6th surface will not reflect sound. If you need to modify the room dimensions to fit your specific garage, keep the room 1.6 times wider that the depth to maintain the Golden Section acoustics.

General Construction Techniques:

We will get as specific as room allows for this article. Unfortunately, we don't have the room to get to every specific detail.

Shell Preparation

The garage will need some modifications to prevent as much sound leakage into the neighborhood as possible.

The side door of the garage may have to be moved into the right area, although it should be approximately correct without moving it. You will probably want to replace the door with a well fitting, solid-core door with proper weather stripping to make an air-tight seal. Often the door is only 30 inches wide, and you may want to modify the opening to accept a 36" wide door.

Garages often have small windows. Any window should be removed and the open area framed in and covered to match the normal garage wall.

The garage door should be fastened shut and get an air-tight seal around the entire opening. The opening for the door should be framed in so that the area has studs, just like the other walls.

In the area where the roof meets the walls, there is usually an air gap of 1/2 to 1". This allows the garage to "breathe". These areas should be well-stuffed with high-quality fiberglass isolation.

The entire wall and roof surface should be closely inspected and sealed with caulk so that there is an air-tight seal to the outside world in all areas except where the roof meets the walls. Pay particular attention to how the wall meets the slab and where there are seams in the siding.

Finally, all of the shell surface area gets a 6" layer of high-quality fiberglass insulation. This includes the wall areas and the entire inside of the roof area. Cracks and gaps between the studs and the door jam of the outside door get stuffed with fiberglass.

Dry Walling the Shell Walls:

Before the dry wall is installed, any electrical boxes needed for switches and outlets are installed. These backs and sides of these boxes should be wrapped in fiberglass insulation to prevent sound leakage. Duct tape can be used to keep the fiberglass in place. The fiberglass should lap-out a half-inch in front of the box so that the installation of the dry-wall compacts the fiberglass, making a good sound seal. The openings in the dry-wall for the electrical boxes should be closely and accurately cut.

All of the shell walls will be dry walled. All dry walling will be applied in two layers of 8'x4' half inch dry wall sheets. The first layer will have the seams running vertically. This layer needs to be sealed with tape and joint compound, to get a good seal between sheets and between the sheets and slab. The second layer is applied with the seams running horizontally. The final layer is sealed with tape and joint compound.

Main Isolation Wall:

Next, we install the main wall that isolates the Studio from the Control Room (per Figure 1) This wall is a double-stud wall with an inner and outer set of studs placed two inches apart. As per the figure, the studs are arranged in a staggered manner so that the vertical studs of the outer wall are placed between the vertical studs of the inner wall. Any opening for electrical boxes (etc.) in the inner wall should be 4 feet away from any opening put into the outer wall.

This main isolation wall goes from the floor to the roof. The inner and outer set of studs each get 6" fiberglass insulation. Dry-walling is done to the inner-surface of the inner wall and the outer surface of the outer wall. Each surface will be two-layers of half-inch dry wall installed in the same way as the drywall sheets were installed for the shell walls. The isolation wall is well-sealed to both the roof, and the slab floor.

Control Room Window:

The window between the Control Room and the Studio is actually two separate windows that do not physically touch. Each window is installed in its own frame and set in a felt or cork filled channel. A felt runner can be placed between the windows to dress up the gap between the panes.

For proper isolation, it is important that the windows are each thick and of different thickness. We recommend (as a minimum) that one pane be 3/8" thick and the other pane be 1/4 inch thick. The different thickness means that the two windows tend to vibrate at different frequencies.

The window on the studio side should slant down so that the bottom of the window is 3 to 4 inches into the opening compares to the top. This slant helps with sound isolation and helps control reflections of instruments' sound off of the studio side of the window.

Inner Walls:

A double inner stud wall is placed whenever a Control Room, Studio or Isolation Room wall is an outside wall of the shell garage. These walls are places two inches from the outer wall, have 6 inches of fiberglass and are covered with two layers of sheet drywall. Single stud walls will separate the Control Room from the Entrance Room and the Isolation Rooms from the Studio and each other. The single stud walls are packed with fiberglass and covered with two drywall layers on both sides. All of these walls use similar construction techniques to the other walls making sure that each layer of drywall is well-sealed. These walls are 8' high.

Doors should be solid core with weather stripping for an air-tight seal. Gaps and cracks between the studs and door jams should be fiberglass stuffed.

Ceilings:

All of the ceilings are suspended ceiling construction with porous (absorbent) acoustic tiles. It is suggested that 2" fiberglass sheeting be placed above the suspended acoustic panels.

Any lighting fixtures that extend into the ceiling should be wrapped with fiberglass. Any access holes for fixtures and cables cut into the ceiling tiles should have cracks/gaps stuffed with fiberglass.

Electrical:

You will want to provide a 90 amp (minimum) service panel for your cottage studio. Off of this service, you will want to run a minimum of four 20 amp circuits. Circuits should be run in metal conduit. Non metallic electrical cabling often doesn't meet electrical codes and, more importantly, radiates a strong magnetic field that can be picked by audio equipment and wiring. An easy to use flexible conduit can be purchased that already has wires installed in the conduit; The greater expense of this type of cabling is well worth it.

Circuits 1 & 2: These circuits are used for lighting and for any "office" plugs in the Entrance Room that are used for office equipment. It is especially important that a copier be on a circuit that doesn't have any studio/control room equipment plugs. Keeping the audio equipment electrically separate from the lighting & office equipment will allow dimmers to be used with the lighting.

Lighting is probably best accomplished with track lighting. Alternatively, in-ceiling fixtures may be used. In any case, the lighting should be incandescent, not florescent.

Circuit 3: This circuit is for your cooling and heating. You can easily verify that one circuit is sufficient if the heating is a gas forced-air furnace. If electrical heat is installed, more heating circuits and a larger central service panel will be required.

Circuit 4: This circuit is for your audio equipment. Studio plugs that will be used for synthesizers and guitar amplifiers are hooked into this circuit. It is important that the ground wire of every plug be separately run back to the service panel and there is a separate ground wire in each run. Do not count on the conduit properly grounding the plug. You can get away with as little as 2 to 3 plugs, using heavy duty extension cords and power strips to branch the power out to where it is needed.

Heating/Cooling:

Heating/Cooling is probably best accomplished by a small forced-air furnace/central air unit installed in the Entrance room. Because of the large amount of insulation, a relatively small capacity until can be used. To determine the exact size, consult with a heating/cooling contractor or building materials supplier.

Lined ducts should branch out close to the unit and be separately run to each room that has a set of registers. Using lined ducts and separately running them, greatly reduces sound transmission through the duct work. Generally, try to use a duct size somewhat larger that a contractor would recommend; the air flow out of large ducts is slower and therefore quieter.

Any openings in walls or ceilings for ducts and registers must be packaged with fiberglass to help maintain a sound barrier.

In Conclusion:

This article has reached it's size limit.

As stated, you should be able to obtain a professional, usable studio converted from your under-used garage area. The result may not be good enough to record metal bands at midnight in a crowded urban area, but you should be able to mix at a reasonable monitor volumes late into the night.

I am experienced enough to know that people will want to use shortcuts to save money. If you are tempted to do this, try to get the installation as close as possible to the plan. This is a relatively inexpensive proposition, especially if you are doing the labor yourself. If you have to save money, try cutting down on heating/cooling and lighting that don't effect sound quality. Remember that it is more expensive to try and bring a poor job up to snuff than it is to do it right the first time.

Figure#1

Copyright 1998, Recording Institute Of Detroit - All Rights Reserved