Creating a Custom Home Theater
Designing for Sound
Basic Overview
I joined AVS to share some of my experience and to learn from the guys and gals who sweat out the details of constructing their own home theaters. I do not consider myself the "know all expert". That is why I am here. I want to learn from you. I have seen some really nice work on this site. We all love this stuff. My client base is luxury homes here in SW Fl so I am definitely not here to sell anything to anyone on this site. I don't think any of my potential client's are surfing through threads. They are not the "DIY" types. Since I am new if you want to learn more about me, my qualifications or experience visit my website (not selling anything). It is listed in my info. It is a continual work in progress. I love quality audio, no not an audiophile (hate that term) and hope to encourage audio design considerations for your theaters. Below is some information on basic room considerations. I know we don't always have control over shapes. I have had to deal with the issue on many projects but if you understand the issues it creates maybe you can make some adjustments to improve. Hope it helps.
This writing is intended for those are starting out in the planning process of building a home theater.
While scanning through some threads I noticed that many focused on the video and interior elements. My intent in this post is to get you to think about the importance of sound quality for your room.
To those who decide to only design for video and interior aesthetics you are missing a large part of the home theater experience.
"I'd rather listen to a mid-fi system in a high-end room than a high-end system in a mid-fi room, any day."
This a quote from Arthur Noxon of Acoustic Sciences.
I am in full agreement with Mr. Noxon on this subject. I use the analogy of putting a race car engine in a minivan. Visit ASC’s website at acousticsciences.com. It contains good information on room acoustics and design. Good information can also be found at Green Glue Company, Quiet Solutions and Kinetics. I’m sure there are many others also. I try and stay with companies that offer independent testing results from certified labs.
Budget ;
Concentrate your efforts and budget on the room and infrastructure first. A solid foundation will result in the ability to improve and upgrade your theater over the years.
A/V gear can be upgraded as finances allow. Most of us do this as new equipment hits the market. Upgrading or renovating the room would be a bit tougher. Build it tight, build it right, the first time.
The Space;
We start here because without the space we have no theater. Are you building new, remodeling or using existing space. Each one has issues that must be dealt with and solutions to be found. With new construction you have the ability to design it right. Avoid using square rooms, cubes, round, and parabolic shapes. Rectangles usually provide the best acoustic results. Rooms that are open to the main house, rooms with irregular shapes and rooms with large amounts of ambient light create issues and in my opinion should not be used or considered for a home theater.
Design the theater to control room modes or standing waves. These are undesirable buildups of sound levels at certain low frequencies. Proper room dimension ratios will assist in limiting room modes and greatly improving sound quality. The following room dimension ratios work best to achieve uniform distribution of modal frequencies.
(ceiling, width, length)
1 : 1.6 : 2.33 (Sepmeyer)
1 : 1.59 : 2.18 (Everest)
1 : 1.4 : 1.9 (Louden)
1 : 1.5 : 2.5 (Louden)
1: 1.78 : 2.46 (mine)
reference base for this information is the Master Handbook of Acoustics by F. Alton Everest, along with my additional research, education and field experience. I suggest reading or referencing a copy if you are designing a theater. It is a great (600 page) Handbook offering in-depth information on almost everything about sound, acoustics principles and room design. It is not written to the amateur. You should have a solid basic understanding of sound and acoustics.
Examples of good acoustic home theater sizes;
8’ ceiling is (8’ h) x (14’ 3”w) x (19’ 7”L).
10’ ceiling is (10’h) x (17’ 10”w) x (24’ 7”L)
12’ ceiling is (12’h) x (21’ 4”w) x (29’ 6”)
If you decide to go outside of these suggested room ratios listed above I suggest using a axial/room mode calculator (available on the internet) to plot out room modes. Watch for double and triple coincidences of frequencies. These result in unnatural and uneven sound boosts and cuts.
Home Theater Room Acoustics;
A home theater room creates high sound levels. It is best to plan for sound containment and sound control. Containment refers to keeping the sound in the room (sound proofing). Control refers to the interior acoustics or sound quality of the listening room. There are many options and price points. Important points to remember are density and isolation for containment and absorption and reflection for control. Good listening room acoustics require a balance of absorption and reflection. The over use of absorption panels will make the room overly dead sounding removing most of the high frequency sound rays. The most common sound absorption panels are made of 6-7 PCF density fiberglass. These panels perform well in the upper mid to high frequencies but will have a minimal effect on the low frequencies. Don’t count on them to sound proof your room. The use of sound diffusion products are effective at scattering of high frequencies improving the acoustical performance of the room. The addition of bass traps in the corners of the room are necessary to absorb excessive buildup of the low frequencies caused by the intersection of walls, floor and ceiling. visit realtraps.com and acoustic sciences,com. There is some good info on bass traps.
For sound proofing of single wall construction I have used the following products on theater rooms I have designed for clients over the years;
Acoustic Sciences Isowall Damp, Isoceiling and Isodeck.
Green Glue
Kinetics IsoMax System
All three offer good performance when installed properly. I strongly suggest that you invest in a good performing sound proofing system. Anyone who has built a theater room without addressing sound proofing knows what I am referring to.
Designing for Sound
Basic Overview
I joined AVS to share some of my experience and to learn from the guys and gals who sweat out the details of constructing their own home theaters. I do not consider myself the "know all expert". That is why I am here. I want to learn from you. I have seen some really nice work on this site. We all love this stuff. My client base is luxury homes here in SW Fl so I am definitely not here to sell anything to anyone on this site. I don't think any of my potential client's are surfing through threads. They are not the "DIY" types. Since I am new if you want to learn more about me, my qualifications or experience visit my website (not selling anything). It is listed in my info. It is a continual work in progress. I love quality audio, no not an audiophile (hate that term) and hope to encourage audio design considerations for your theaters. Below is some information on basic room considerations. I know we don't always have control over shapes. I have had to deal with the issue on many projects but if you understand the issues it creates maybe you can make some adjustments to improve. Hope it helps.
This writing is intended for those are starting out in the planning process of building a home theater.
While scanning through some threads I noticed that many focused on the video and interior elements. My intent in this post is to get you to think about the importance of sound quality for your room.
To those who decide to only design for video and interior aesthetics you are missing a large part of the home theater experience.
"I'd rather listen to a mid-fi system in a high-end room than a high-end system in a mid-fi room, any day."
This a quote from Arthur Noxon of Acoustic Sciences.
I am in full agreement with Mr. Noxon on this subject. I use the analogy of putting a race car engine in a minivan. Visit ASC’s website at acousticsciences.com. It contains good information on room acoustics and design. Good information can also be found at Green Glue Company, Quiet Solutions and Kinetics. I’m sure there are many others also. I try and stay with companies that offer independent testing results from certified labs.
Budget ;
Concentrate your efforts and budget on the room and infrastructure first. A solid foundation will result in the ability to improve and upgrade your theater over the years.
A/V gear can be upgraded as finances allow. Most of us do this as new equipment hits the market. Upgrading or renovating the room would be a bit tougher. Build it tight, build it right, the first time.
The Space;
We start here because without the space we have no theater. Are you building new, remodeling or using existing space. Each one has issues that must be dealt with and solutions to be found. With new construction you have the ability to design it right. Avoid using square rooms, cubes, round, and parabolic shapes. Rectangles usually provide the best acoustic results. Rooms that are open to the main house, rooms with irregular shapes and rooms with large amounts of ambient light create issues and in my opinion should not be used or considered for a home theater.
Design the theater to control room modes or standing waves. These are undesirable buildups of sound levels at certain low frequencies. Proper room dimension ratios will assist in limiting room modes and greatly improving sound quality. The following room dimension ratios work best to achieve uniform distribution of modal frequencies.
(ceiling, width, length)
1 : 1.6 : 2.33 (Sepmeyer)
1 : 1.59 : 2.18 (Everest)
1 : 1.4 : 1.9 (Louden)
1 : 1.5 : 2.5 (Louden)
1: 1.78 : 2.46 (mine)
reference base for this information is the Master Handbook of Acoustics by F. Alton Everest, along with my additional research, education and field experience. I suggest reading or referencing a copy if you are designing a theater. It is a great (600 page) Handbook offering in-depth information on almost everything about sound, acoustics principles and room design. It is not written to the amateur. You should have a solid basic understanding of sound and acoustics.
Examples of good acoustic home theater sizes;
8’ ceiling is (8’ h) x (14’ 3”w) x (19’ 7”L).
10’ ceiling is (10’h) x (17’ 10”w) x (24’ 7”L)
12’ ceiling is (12’h) x (21’ 4”w) x (29’ 6”)
If you decide to go outside of these suggested room ratios listed above I suggest using a axial/room mode calculator (available on the internet) to plot out room modes. Watch for double and triple coincidences of frequencies. These result in unnatural and uneven sound boosts and cuts.
Home Theater Room Acoustics;
A home theater room creates high sound levels. It is best to plan for sound containment and sound control. Containment refers to keeping the sound in the room (sound proofing). Control refers to the interior acoustics or sound quality of the listening room. There are many options and price points. Important points to remember are density and isolation for containment and absorption and reflection for control. Good listening room acoustics require a balance of absorption and reflection. The over use of absorption panels will make the room overly dead sounding removing most of the high frequency sound rays. The most common sound absorption panels are made of 6-7 PCF density fiberglass. These panels perform well in the upper mid to high frequencies but will have a minimal effect on the low frequencies. Don’t count on them to sound proof your room. The use of sound diffusion products are effective at scattering of high frequencies improving the acoustical performance of the room. The addition of bass traps in the corners of the room are necessary to absorb excessive buildup of the low frequencies caused by the intersection of walls, floor and ceiling. visit realtraps.com and acoustic sciences,com. There is some good info on bass traps.
For sound proofing of single wall construction I have used the following products on theater rooms I have designed for clients over the years;
Acoustic Sciences Isowall Damp, Isoceiling and Isodeck.
Green Glue
Kinetics IsoMax System
All three offer good performance when installed properly. I strongly suggest that you invest in a good performing sound proofing system. Anyone who has built a theater room without addressing sound proofing knows what I am referring to.
lol
