Sheetrock transmission Loss

Sheetrock transmission loss in wall assemblies

Sheetrock transmission loss data IR 761
“Results of sound transmission measurements to show ability to reproduce the same results after a complete specimen rebuild. The upper curves are data for the nominal STC 57 wall while the lower curves are for the nominal STC 46 wall.”

Noise Isolation Provided by Gypsum Board Partitions
With the exception of partitions built with single wood studs without resilient furrings, there is an approximate 5 point STC rating increase each time the gypsum boards are doubled on either side of the partition. At low frequencies, the transmission loss is increased by about 5 dB for every doubling of the gypsum boards on one side of the partition.

USG The Gypsum Construction Handbook
“Outlines methods for matching systems to specific performance criteria. Covers fire and sound criteria, wood and steel partitions and sound control systems. Specialty systems include area separation walls, cavity shaft walls, fireproofing, curtain wall/fire containment systems, thermal insulation, air water and vapor control.”

Soffit Mounted Monitors

Speakers mounted in soffits or in the wall

“Speakers have two theoretically ideal working conditions. The first is if its radiation space is into a full space (spherical radiation) or into a half space (hemi-spherical radiation). To achieve ideal full space conditions the speaker needs to be small compared to the radiated wavelength. Because the speaker front baffle is small the higher the frequency the smaller the radiation angle will be.”

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Basement moisture control

Basement moisture control starts when designing.

One of the main reasons a basement gets or stays wet is due to the walls being below ground level and subject to the moisture that the Earth contains, that’s one reason. Another is the fact that the Earth is cooler and if the temperature/dew point is elevated above the exterior wall then you have a classic example of “warm to the cold side” path when temperature seeks equilibrium. Still a third reason is the typical porous cinder blocks used in the construction that can retain water.

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STC of Isolation Assemblies

STC of simple wall assemblies, isolation and sound proofing

Calculation of STC, MTC, OITC and Rw explained
“Note: This document is an extension/adaptation of a document explaining STC and OITC It is expanded (+ additional adjustments and more in-depth comments) with the MTC and RW single number rating.”

Acoustic Shaping
“In the preceding sections we showed that significant forces could be generated in unsteady fields, especially standing wave fields, due to interaction between the field and solid (or liquid) particles.”

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Insulate a Recording Studio

A poor example of installing insulation in ANY environment.

This video begins explaining how insulation has no ability to stop sound in a wall assembly.

It does stop high frequency but this is not the main reason for installing insulation in your recording studio or home theater walls.

The insulation is to dampen the wall panels when vibration occurs. Insulation is also a wise choice in your building or room perimeter walls that are in contact with outside elements.

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Resilient Channel installation guide

Install RC (resilient channel NOT hat track) proper

The only reason this video made the cut is because it shows Resilient Channel installed properly.
This is one of the main reasons for this product [resilient channel] failing, improper installation.

Further discussion about walls and how the materials interact with one another, the potential for what is referred to as the drumming effect and what to expect when no insulation is installed in the cavity(no damping of the panels).

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Flanking and walls

Flanking in your walls

The consequences of architectural design. What a concept!

Designing for confidential privacy is the same thing as designing so your neighbor isn’t experiencing your music!

Knowing where you are in speech levels gives you an idea of what you are going to have to do to get your frequency levels down to an acceptable level. If you can hear the neighbors, the neighbors can hear you!

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Doors and window framing

Doors openings and window framing

Often a place of question in a home theater or recording studio is the doorways and window framed areas. It proves to be simple but requires some information from the builder to do it right the first time.

This video gives a quick and easy demonstration that covers everything you need to know for cutting framing material and installation of an opening.

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Building a straight wall

Construct a straight flat wooden framed wall

Building a straight wall is critical

 Maybe you have never even considered this.

All the different species of lumber is grown and milled so quickly in this Century that the tendency to bow, twist and warp is high. Fact is, depending on the quality of the lumber from “kind of warped” to the “super straight” framing material you pay accordingly.

In addition another thing that is the biggest reason lumber will warp, bow and twist…the weather. Wood laying in direct sunlight will begin to loose moisture and the ability to build a straight wall decreases as the material warps and bows and twists. Rain can be just as bad in that it makes the wood a bit more difficult to handle. But if left in the sun, it too will soon take a different shape. For this reason and this reason alone, sun and rain and all that weather brings, protect it by covering with a substantial water proof plastic.

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Acoustic isolation / sound proofing

Soundproofing a home recording studio

Soundproofing on “Holmes on Homes”

This is a good example of what is called “isolation” and how to do it. Isolation is often confused with acoustical treatments. This has always been incorrect.

The sponsor is Quietrock(r) so thier product is used in this video. For your home theater or studio, standard sheetrock can be used with very good results.


Look closely as this video plays. After the sheetrock has been removed from the wall you can clearly see two(2) different stud framing sides to this wall. This is a simple “decoupling” technique that will give you a better rated wall then a simple one row stud framed wall.

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