Media Room Construction

Video Asylum

TVs, VCRs, DVD players, Home Theater systems and more.

I am working with an architect to design a room over my existing garage and need help with the design for optimal acoustics. Â I want to minimize the cost for post-construction acoustic treatments and also would like to build in as much as possible. Interior design considerations will need to prioritize the sound quality, listening and viewing positions and issues over any aesthetic concerns (both are important). Â While a home theatre with a motorized, built-in ceiling screen and video projector will be incorporated into the room design. Â The screen should be built to come down into a "shadow box" Â for better contrast in low light situations. Â It will be a modest system since most of the budget will be spent on Hi-End 2 channel audiophile equipment.
Can anyone recommend an honest and reasonable consultant in the New York Metro Area????
Here are a few of the tips I have accrued thus far:
Â
First I need to define room dimensions Â that will work acoustically and still allow the installation of "hidden" acoustic treatment which includes the necessity for sound isolation from the rest of the house as well as sound absorptive materials. In general, at least six inches of additional depth must be calculated into the final room dimensions to accommodate the aforementioned treatments. Â Here are some of my notes so far with my own limited research which will obviously be imbellished by the acoustic consultant:
1.Room dimensions:
A. 17 feet wide by 19 feet long , must be an odd ratio?
B. Â Room height 9 feet must account for additional height of "floating floor" and the possibility of a "false ceiling"
C. Pitch ceiling height lower over speakers, higher over listener? Â To do this the speaker and listener position must be defined relative to the room dimensions.
D. Build bass traps into the wall with corner loaded bass traps
E. Bass trap all four vertical corners and the ceiling perimeter corner Â with a soffit bass trap
C. Wall/stud resonance treatment and constrained layer damping: 1. Sandwich two layers of sheetrock ? Gyproc Soundbloc 1.5 soundproofing plasterboard. Â 2. Â Suspend sheetrock off studs by screwing into resilient metal fir strips called "z-metal" or "RC-1" 2. Visco damping material Â {1/16 " thick double sided adhesive visco-elastic sheet} Â is applied between the z-metal and the first sheet rock layer and a second visco-elastic sheet between the first and second layers. Â In place
of double sided adhesive visco-elastic sheet, can 100% glue to both sides a layer of sound board {firtex or celotex}. Â The ceiling must be treated the same way.
D. Locate entry door behind the listener but Â on a SIDE WALL {nowhere near the speakers since the door will raddle} NOT ON A BACK WALL AND not flush to the corner and at least 2 feet from the corner. Door cannot rattle? Heavy acoustic door/frame?
E. Windows are very tympanic
and should be minimized. Â Tall narrow windows are best.
Must not use standard thermal type instead use 2 layers of thick laminated glass [like that used for glass shelving in stores] Â separated by at least 4 inches of air space. Â The air space must be vented into the wall cavity. Â Set the glass into a bed of visco-elastic damping material. Â The glass sheets should be of different thicknesses.
F. Lighting should be subdued, indirect, and dimmable. Â Do not use standard Â wall dimmers since they will often hum or buzz. Â Use a variable voltage transformer. Consider low voltage lighting. Â Do not use ceiling light cans, they rattle. Â The best light has a ceiling bezel and lens of thick rounded glass.
G. Address side wall, rear wall, and ceiling reflections which are determined by speaker placement. Room dimensions must account for acoustic panels.
H. Need to decide how to handle ceiling reflections other than simply pitching the ceiling height. Â For example should the ceiling have a built-in architectural, antireflective and absorbing pattern wavy, geometric shapes, wood slats, or simply use sound panels and a cloth cover for concealment?
I. With the sound isolation from the outside and the rest of the house, care must be taken with the ventilation since there will essentially be an airlock once the door is closed. Â The Â HV/AC system must be carefully planned to avoid vibrations within the ducts (e.g. electric baseboard heating, radiant heat etc). Â Perhaps a separate heating and internal cooling unit which is quiet and preferentially capable of cooling or heating the room prior to the listening session. Â
J. Â While windows that are not treated as described above may be very tympanic, a sealed anechoic chamber will sound too dead and is also not our goal. Â Windows, properly designed and placed can help release some of the sound pressure, which may be required.
So as you can see, without sounding (no pun intended) too pedantic, there are many details that only an experienced acoustician can properly address and implement into the room design to make a comfortable, aesthetically pleasing and acoustically outstanding space, well worth the financial investment. Â Many of the above design considerations require a computer software program. Â Also, there are many companies which manufacture acoustic treatments and this can become an expensive aspect of the design with no end in sight. Â It would be a mistake not to have an experienced person select the most cost-efficient materials. Even after the room is finished, acoustic measurements and computer analysis will be needed for optimal speaker placement and final touches on the acoustic room treatment, especially once the furniture and equipment is are in place.
I have attached Â jpeg files of the initial room plan.

Any help or suggestions would be greatly appreciated.

This post is made possible by the generous support of people like you and our sponsors:

McShane Design

Topic - Media Room Construction - DBK 16:49:09 12/12/04 (0)

You can not post to an archived thread.