Should You Use SilentFX Drywall To Soundproof?
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There are several acoustic drywall brands on the market and one is SilentFX by Certain Teed. This is a Saint Gobain company who also make Green Glue. In this article I will go over the pros and cons of using SilentFX drywall in your soundproof studio build.
1) What is SilentFX Drywall
According to Certain Teed, "SilentFX Noise-Reducing Gypsum Board is specifically designed to reduce airborne sound transmission between two adjoining spaces when used in wall or floor/ceiling assemblies."
They go on to say that, "SilentFX features a viscoelastic polymer that dampens sound energy. Application of the viscoelastic polymer between two specially formulated dense gypsum cores results in a combination that significantly improves sound attenuation and is ideal for systems requiring high STC performance."
It is important to note that Green Glue and Mass Loaded Vinyl are both used to dampen sound energy as well. This middle layer viscoelastic polymer in SilentFX is meant to replace the need for Green Glue or Mass Loaded Vinyl.
2) What Is A Viscoelastic Polymer
According to a paper from Taiyuan University of Science and Technology, "The viscoelastic damping layer, most of which is rubber or rubberlike polymers, represents hysteresis under a dynamic load. Part of the mechanical energy is absorbed and finally dissipated as heat due to the internal friction of the molecular chains." So, in plain english, these means that the material vibrates in such a way that acoustic energy is transformed to heat, thus eliminating some of the sound or noise coming through your wall.
3) How Does Silent FX Compare to Regular Drywall
One of the best ways to soundproof a wall is to build a double wall system with an air gap in between the two walls. This system involves two layers of 5/8" drywall on either side of each wall. The STC rating you get from this design is 63.
According to Certain Teed's technical data sheet their equivalent double wall system gets an STC rating of 62. Their wall uses one layer of 5/8" on one side and a layer of 5/8" SilentFX drywall with a layer of 5/8" type X drywall on the other side. The biggest difference between the two wall designs is one has two layer of 5/8" on each side while the Certain Teed wall uses three layers with one being their patented SilentFX drywall.
4) What Is The Cost Difference Between SilentFX and Regular Drywall?
SilentFX costs $73.01 per 4x8ft sheet. This is from Campbell Supply Company. (ā5/8" Acoustic Drywall, Silent FXā) Type X 5/8" drywall costs $17.87 for a 4x8ft sheet. The cost of installing a the Certain Teed double wall would be a total of $126.62. The cost of a double wall without Silent FX would cost you $71.48.
That is a difference of $55.14 and you are not getting a better STC rating.
Conclusion
I wouldn't recommend SilentFX drywall for most home recording studios. It might be helpful if you are building a normal wall system and want some added acoustic benefit over regular drywall. However, the cost of acoustic drywalls like SilentFX never seems to justify the added acoustic benefits. For this reason I never recommend specialty drywalls to my clients. I always like to stick with regular Type X 5/8" drywall. You get the better results for less money.
Works Cited:
ā5/8" Acoustic Drywall, Silent FX.ā Campbell Supply Company, campbellsupplycompany.com/5-8-acoustic-drywall-silent-fx/. Accessed 2 Oct. 2023.
Wang, J.; Sun, D.; Liu, S.; Zhang, X. Damping Characteristics of Viscoelastic Damping Structure under Coupled Condition. Math. Comput. Appl. 2017, 22, 27. https://doi.org/10.3390/mca22010027
Websites Referenced:
https://www.certainteed.com/resources/CTG_2480_SilentFX_Brochure_Eng.pdf
https://www.homedepot.com/b/Building-Materials-Drywall-Drywall-Sheets/5-8-in/N-5yc1vZbb52Z1z0ppqa
