Frequently Asked Questions


1. What is BASWA Phon?   The BASWA Phon Seamless Sound Absorbing Plaster System is used to reduce reverberation time making voice, music and other sound much more intelligible. The system comprises a Factory Coated & Sanded Supporting Panel made of mineral fiber which is adhered onto a stable substrate, such as drywall and is then seamlessly coated with a micro-porous marble coating of BASWA Phon Fine and/or Base.

2. What is acoustic / sound absorption?   Acoustic absorption refers to the process by which a material takes in sound energy when sound waves are encountered, as opposed to reflecting the energy. All materials are either acoustically absorbent or reflective. Hard surfaces such as glass or concrete tend to be more reflective, while soft surfaces like furniture, drapery or carpet are absorptive. Acoustically absorptive materials are typically rated with an NRC Rating.

3. What is an NRC Rating?   Noise Reduction is the amount of noise that is reduced through the introduction of sound absorbing materials. A Noise Reduction Coefficient (NRC) is the average of a material’s absorption coefficients at 4 frequencies of 250, 500, 1000, 2000 Hertz. This number is between 0 and 1; zero being perfectly reflective and 1 being completely absorptive.

4. What is Reverberation / Reverberation Time?   Reverberation is sound resonance, or an echo. Reverberation time is the time it takes for sound to decay by 60 dB once the source of sound has stopped. Reverberation time is affected by the size, shape and volume of the space and the amount of reflective surfaces versus the amount of absorptive surfaces within a space.  Reverberation has an important impact on speech intelligibility, and can affect safety, learning, or the quality of an everyday conversation.

5. How does BASWA Phon work?   High frequency sound absorption is accomplished by allowing sound wave energy to pass through the micro pores in the finished surface thereafter dissipating into heat energy in the mineral wool. When low frequencies hit the BASWA Phon Finish, the surface vibrates like a diaphragm. These vibrations are then converted to heat energy as well. BASWA Phon has a noise reduction coefficient rating up to 1.05, unmet by other products. This diffusing of extreme frequencies allows for clearer sounds in any room, hall, atrium, or auditorium. BASWA Phon absorbs consistently high in all frequencies.

6. What type of projects specify BASWA Phon applications? Is it appropriate for a Private Residence? Are there examples of projects that have incorporated BASWA Phon? BASWA Phon is installed in a wide variety of project types, from Yale University to the White House, Utah Museum of Natural History to Dallas Cowboys Stadium, and Carnegie Hall to private residences. A full portfolio of projects that have incorporated BASWA Phon is available here.

restaurant, noise, acoustics, loud, acoustic treatment      

7. Where is BASWA Phon available?   BASWA Phon is available globally. Find your local contact.

8. Can walls be soundproofed with BASWA Phon? What is the difference between sound absorption and sound transmission loss?   In truth, very little is sound "proof." However, excellent sound control can be achieved with the right product. If you want to reduce the noise level in a room, add sound absorption. If you want to reduce the transmission of noise from one room to another, add high sound transmission loss values to your walls, ceilings, and floors. BASWA Phon can add 5-7 points to STC rated wall or ceiling. The STC (Sound Transmission Class) is a single-number rating of an assembly's ability to resist airborne sound transfer. In general, a higher STC rating blocks more noise from transmitting through a partition.

9. How is an acoustical wall or ceiling panel different from the BASWA Phon system?   BASWA Phon is not just an acoustical panel, but a full system that allows for a seamless, monolithic look while absorbing up to 100% of the sound that comes in contact with its surface. While BASWA Phon does include a Supporting Panel as part of the full System, there are more components necessary that create the aesthetic of the System. BASWA Phon is not a drop in grid system.

10. Will you work directly with my Architect or Designer?
The BASWA acoustic team has worked with hundreds of Architectural Firms all over the world. We have the experience to quickly get all required information to a firm as it is needed. Contact BASWA acoustic to discuss your project. 



1. What are the limitations to the BASWA Phon System?   BASWAphon can be installed on a wide variety of surfaces. Up to 5,000 sq ft without a control joint can be applied to curved, flat, domed, vaulted or complex curved surfaces, down to a 2 foot radius.

2. Why should I use BASWA Phon over other products?   The beauty of a finish is just as important as the acoustic qualities. Where some acoustic plasters may come as a sprayed "popcorn" finish or made of puncturable materials made of questionable integrity, BASWA Phon creates a smooth and seamless surface made of durable marble. BASWA Phon follows the contours of a room, curving across domes or across arched ceilings and creates an elegant and effective environment for events, get-togethers and general purpose rooms. In addition to these qualities, BASWA Phon has the following advantages:
   +  THE ORIGINAL. The original, most specified sound absorbing plaster system, with 25 years of installations.
   +  SEAMLESS, FLAT, CURVED, DOMED, AND VAULTED SURFACES. 5,000 sq ft without a control joint can be applied to flat or complex surfaces.
   +  HIGHEST SOUND ABSORPTION. NRCs up to 1.05, making it the most sound absorptive plaster on the market.
   +  TINTED TO MATCH ANY COLOR. No adverse effects on acoustical performance with uniform color.
   +  MADE IN THE USA. Only sound absorbing plaster system with Swiss engineered components made in the US.
   +  GREAT IN HUMID ENVIRONMENTS. Not water soluble, perfect for spas, natatoriums or porte-cochères. Rated 10 / 10; no mold growth per the ASTM D 3273.
   +  DURABLE MARBLE FINISH. Coatings are made of a crushed marble aggregate.
   +  FACTORY COATED & SANDED SUPPORTING PANEL. No onsite panel sanding. Panel will not separate or compress. Panel require no seam taping or glue; no telegraphing seams.
   +  OVERNIGHT DRYING TIMES. Typical drying time between coats is overnight.
   +  LIGHT WEIGHT. Approximately 1.5 lbs per square foot.
   +  LEED CONTRIBUTION POINTS IN 9 CATEGORIES. Up to 95% recycled, SDS friendly, high light reflectance and R-value. No VOCs; California Section 01350 compliant.
   +  FIELD APPLIED BY CERTIFIED, LOCAL INSTALLERS. Over 115 Local Independent Contractors trained on-site. Installation takes 4 to 5 days; no field measurements, no shop drawings.
   +  NO DRYWALL BLOCKING. Not required for light fixtures, diffusers or terminations.
   +  ACCESS PANELS. Trimless access panels up to 8’x 8’ available with BASWA Phon Finish on the face.

3. Can BASWA Phon be used as part of a LEED project?   BASWA acoustic is always following the latest in LEED revisions and maintains the compliance of the BASWA Phon system within these guidelines. Additionally, BASWA Phon Systems are up to 95% recycled materials, SDS friendly, with high light reflectance and a high R-value. BASWA Phon has no VOCs and is compliant with the California Section 01350. More information is available here. 

4. Where can I find Details, Specification, SDS or other technical information?   All technical data for BASWA Phon is available here. If you are in need of specific details or submittal information, please contact BASWA acoustic

5. How much does BASWA Phon cost?   The installed cost of BASWA Phon will vary by BASWA Phon Finish specified, size and shape of the installation, and BASWA Phon Installer. For fair pricing of the BASWA Phon system, please contact BASWA acoustic for approved and certified BASWA Phon Installers.

6. Can BASWA Phon be installed in any color? Can it be painted? Will it affect the acoustical performance?   BASWA acoustic does not believe owners and designers should be limited in choices of finish colors. BASWA Phon can be matched to any color or multiple color gradients, tying the finished surfaces into the overall design aesthetic of the space. In no way does the tint affect the acoustical absorption qualities of BASWA Phon, as these colors are integrally added to the product before application.

If mural or decorative accent painting is desired, care must be taken to select a paint that is not likely to bridge pores, such as a water based paint. Acoustical ceilings perform through the porosity of their surface and lose their acoustical absorption when painted with traditional paints.

Contact BASWA acoustic to find out more about color and how you can start planning your new finish.

7. Can BASWA Phon Base & Fine be applied directly to drywall?   Specialty BASWA Phon Finishes can be directly applied to drywall to allow for the fine tuning of sound within a space, absorbing the high end frequency range. This type of application is best for performance spaces with challenging high frequency regulation needs and will not affect the overall dynamism of the performance. Third party test data for Specialty Finishes available upon request.



1. How long is a typical BASWA Phon installation?   A typical installation takes 4-5 days. Typical drying time between coats is overnight.

2. Who Installs BASWA Phon? Can my builder or I install the BASWA Phon System?   BASWA Phon is installed by Certified Installers that are trained by BASWA acoustic in order to ensure a successful application and high performance sound absorption. New companies may be certified for installing. Any interested parties should contact our Contractor Sales department

3. Is there a local installer in my area?   BASWA acoustic has certified installers, through on-site training, all over the world. For a list of approved and certified BASWA Phon Installers, contact BASWA acoustic.

4. I plan on putting recessed lighting, speakers, diffusers, etc. in my ceiling.  Can BASWA Phon be installed on such a surface?   BASWA Phon can be integrated into any design concept and can be installed around light fixtures as well as access panels and speakers. By roughing in these items, the lighting and speakers can be flush with its surface. No pre-installation measurements are needed as all cuts are made onsite to accurately fit each light, speaker, diffuser, access panel, etc.

5. How is BASWA Phon installed over curved surfaces?   BASWA Phon can be applied to curved, domed, vaulted or warped surfaces. In order to make the panels more flexible, the backs are factory-scored in one or two directions. For extreme applications, the glass bead crust can be heated. The panel becomes pliable and can be fitted to the curved or domed surface. The panel is then screwed in place until the adhesive is dried. Screws are then removed and screw holes are filled with Pre-Fill, the same material used to factory coat the panels. This ensures monolithic acoustical absorption without potential telegraphing of mechanical fasteners.

6. What is the recommended substrate for the BASWA Phon system?   BASWA Phon can be installed over many types of stable substrates. It is most typically installed over taped drywall, no additional finishing of the surface is needed.

7. How are the BASWA Phon panels attached to a substrate? How big are the panels?   BASWA Phon Supporting Panels are adhered to the substrate using the plaster based BASWAphon Adhesive. The panels, which are 2’- 8” x 1’- 11”, are heat bonded mineral wool panel with a factory coated and sanded 6mm crust of recycled glass beads. Panels are available in 3 thicknesses: 26mm, 36mm, and 66mm. The difference between thicknesses is the measurement of the mineral wool layer only.



1. What if there is damage or staining that occurs to the BASWA Phon surface?   Under normal circumstances, BASWA products age evenly and do not require any maintenance. However, surfaces may be damaged by punctures, stains, or water. Similar to most building materials, a BASWA surface may accumulate a buildup of dust particles. Acoustical ceilings perform through the porosity of their surface and therefore can not be cleaned with conventional products. BASWA acoustic has developed a range of techniques and products, which allow for removal of staining or repair of surface damages without affecting the acoustical performance. See the list of products available here

2. What if a change in color is requested in the future?   If the is a desire to change the color of the application, contact BASWA acoustic to discuss the options available to refinish the surface. 

3. Are there warranties available?   Warranties are available for BASWA Phon installations. Contact BASWA acoustic to learn more. 


If you have a question that has not been answered, please contact us.

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