Insulation stc rating chart. Metal studs perform better than wood studs.

Insulation stc rating chart. Of course, the higher the STC rating, the better.

Insulation stc rating chart Installer & Retailer Locator. Fiberglass and mineral wool insulation contribute the biggest gains. Sources of Airborne Noise: Conversations, televisions, music, and STC: 45 Report No. NIC is a field-tested value that accounts for all the construction systems separating the two adjacent rooms. STC rating chart . Visit our website atwww. The higher the STC number, the greater the reduction in sound. For example, if you have a type of insulation that has an R Continuous Insulation for Rain-Screen Cladding Systems - Fiber Cement Panel Continuous Insulation for Cavity Wall Systems. Below are the STC ratings of various wall assemblies, each presented to help illustrate concepts, improvements and rules of thumb. Acoustical Assemblies STC Rating Reference Guide. The estimated ratings are based on laboratory test results from various compendiums of STC ratings. How It Works: Airborne noise travels through air gaps and weak points in walls and floors. • An empty framed wall (steel studs and a layer of gypsum wallboard on each side) has an STC of approximately 35 Transmission Class (STC) ratings demonstrate its effectiveness in attenuating noise. 4 dB Assembly Components Membrane: Insulation: Insulation Deck: 0. The Chart below shows how noise relates to decibel ratings. , Type B, Steel Acoustic and Thermal Performance STC: 29 OITC: 23 RValue: 23 Rainfall: 55. *OITC is estimated based on this test. The sharp sounds that easily transmit through normally insulated structures are subdued by the increased mass of cellulose. Learn about glass sound insulation, the importance of Sound Transmission Class (STC) ratings, and how higher STC ratings help reduce sound transmission. 51” Fabral 22ga. Email Us. Transmission The passage of sound waves from its source, through a vibrating medium, and to a listener. The STC rating is the total frequencies divided by the Please reference the below STC ratings chart if you haven't already for a brief overview of the different ratings and what they mean. Achieve greener insulation solutions today! Skip to content. But what does that really mean? A sound transmission class chart is a simple way to understand the decibel scale and its relation to STC ratings. A higher sound transmission class rating indicates Looking at the chart above, once a wall gets to an STC of 45, loud speech is audible but not understandable. The higher the STC rating, the better the sound isolation. The STC (Sound Transmission Class) rating is a single-number rating system for interior building partitions and viewing windows used to STC Rating of Fiberglass vs Rockwool (Which one insulates the best) Note: Here I will be going over which type of insulation material works best when put inside a typical interior wall with ½” of drywall on either side, which has an STC rating of 34 on its own, and how it increases this rating. STC Rating Chart. Open cell spray foam ties with standard How to Read an OITC Rating Chart. Find resources for UL assemblies with required STC and fire ratings to integrate into your construction project. 77” GAF" Polyisocyanurate 1. 2. Glass size and glazing system will affect STC rating. The farther soundwaves have to travel, It contains STC (Sound Transmission Class) or HC (Impact Insulation Class) ratings for approximately 500 different construction assemblies. txt) or read online for free. Caution: You cannot add STC ratings. If you have an STC 33 wall and decide to add another sheet STC rating. STC Rating: What can be heard at this level: 25: Soft speech can be heard and understood: 30: For example, a standard interior wall that consists of two sheets of ½ inch drywall separated by wood studs and no insulation has an STC rating of 33. IIC Ratings Chart IIC Ratings vary dramatically depending on finish floor, subfloor, ceiling structure below, and of course, use of an IIC-rated sound mat. The STC (Sound Transmission Class) rating is a single-num ber rating system for interio r build ing partitions and viewin g STC ratings by up to 10. * * [The data and information set forth are based on samples tested and are not guaranteed for all samples or applications. 800 Impact Insulation Class (IIC) Resources. 0 perms or less; FSK-25 and Foil Faced: 0. STC: 26 OITC: 21 RValue: 23 Rainfall: 54. At around 55, Drywall without any other insulation, such as foam, is not a good insulator in itself as the sound waves travel right through it. In multi-family housing Rockwool Premium Plus™ Insulation has one of the highest STC ratings for a party wall assembly, 69*. IIC stands for Impact Insulation Class. 7 dB Assembly Components Metal Roof System Find Revit and CAD files for STC and fire rated UL assemblies. The use of insulation in a typical metal stud wall, staggered wood stud or other wall with isolated face, can increase sound transmission loss by about 8dB – an improvement that is readily noticeable. What is STC? The Sound Transmission Class (STC) is a single-number rating of an assembly’s ability to resist airborne sound transfer at the frequencies 125-4000 Hz. Insulation. jm. Both categories of SPF are chemically Then, they calculate the sound transmission loss between the spaces. Similar to STC, the higher the OITC value, the better the wall assembly is at reducing sound transmission. The key points to remember are: (1) The insulation is performing a sound absorption function in the stud cavity. STC is widely used to rate interior partitions, ceilings/floors, doors, and windows. Metal studs perform better than wood studs. In general, a higher STC rating blocks more noise from transmitting through a partition. . Here we define STC - sound transmission class and we provide a table of design details that show STC rating for various building wall framing designs. Of course, the higher the STC rating, the better. The STC rating is determined by testing the partition's ability to isolate sound Sound Control Insulation Exceptional sound and noise absorption Excellent Thermal Performance (R-value of 3. Typical STC Ratings for Common Materials. ASTM E 413-04 Classification for Rating Sound Insulation STC Rating for Underwriters Laboratories (UL) U370 Using GreenFiber FRM PM-6. Sound Transmission Class (STC) is an integer rating of how well a framed wall attenuates sound. Of course, the higher the STC rating, the See Forms Available chart: Water Vapor Permeance: ASTM E96: Kraft Faced: 1. 14a Laboratory measured STC and OITC ratings and Rw for various glass conﬁgurations. B. Here’s a table showing what each STC rating represents: Fiberglass (or traditional) insulation falls in the middle range of options bringing the STC rating to 39. significantly improve an IIC rating. The chart below indicates the STC rating of specially made acoustic doors using various applications of gasketing. Buildings insulated with cellulose have a noticeable "quietness". Metal building insulation can absorb interior noise to provide a Class (STC) side to the other. The STC rating reflects the decibel reduction in noise that a barrier can provide. The STC rating goes all the way up to 65. STC Rating Chart For Windows. ] SVC Rw summer TL 85-198 TL 85-170 - - TL 85-234 stc_rating_chart. An additional benefit is that it provides a better acoustical environment both inside and outside the building when compared to metal buildings without insulation. These R-values are a sum, meaning this should be the total R-value once you add up the entire depth of insulation. STC Rating of Fiberglass vs Cellulose (Which one soundproofs the best) Note: Here I will be going over which type of insulation material works best when put inside a typical interior wall with ½” of drywall on either side, which has an STC rating of 34 on its own, and how it increases this rating. 1/8" 36 36 3/8" (10 OITC* Frequency (Hz) 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 By combining insulation, gypsum board mounted on resilient channel, and two layers of 1⁄2 inch gypsum board on one side, a very good STC rating of 52 can be achieved. In addition the Sound Transmission Loss (TL) and Impact Sound Pressure Level (ISPL) data values for each test are plotted on graph paper at a standard scale. As discussed above, building code requires STC 50 for corridor and demising walls when building apartments and condos. This chart summarizes various characteristics of five most common house insulation materials: closed cell spray foam, open cell spray foam, rock wool (a. Adding standard fiberglass insulation improves the rating to STC 39. STC Rating Documents. 53 mm) 1/4" 0. • Doubling the mass of a wall assembly does not double the STC rating. Bradford Road, Littleton, CO 80127, Find resources and details for UL rated wall systems with the required STC and fire ratings for your project. If your building’s walls or roof have a low rating, you can hear almost everything happening on the other side, even if the person is speaking softly. Installing sound insulation in certain parts of your house can have a significant impact on acoustic comfort. as your home. ﬂ] Specifications Naturally better insulation. at SOUND TRANSMISSION CLASS RATINGS. The STC rating figure represents approximately the decibel reduction in noise that the assembly can provide. "The Facts About the Acoustical Performance of Metal Building Insulation 2", Sound Transmission Class, General Steel Corporation, 10639 W. *OITC is estimate d base d on this test. The Sound transmission class (STC) ratings solve that problem by giving a single value to acoustical performance for a door. Sound transmission class (STC) is a single number rating of sound isolation of a building wall assembly. Understanding IIC Claims. 0 Sell Sheet NAIMA Fiberglass and Mineral Wool Insulation as an Alternative to Sprinkler System. Batts. 8 per inch) Adds STC value to wall and ﬂ oor-ceiling assemblies Provides life saving ﬁ re protection in rated assemblies Fire resistant to temperatures above 2,000°F (1,093°C) Conserves energy, reduces Greenhouse gas and carbon The STC wall rating chart measures between 45 – 80. an assembly comprised of ⅝” gypsum board, steel studs and ROCKWOOL SAFE’n’SOUND® insulation will produce an STC rating of STC Ratings Chart Acoustical Performance of Glass and Wall Constructions Overall Thickness Inside Construction Space Outside STC Value ISO RW 3 Single Laminated Glass 1 1/4" (7. Wall Assemblies with thermal batts provide Acoustic Ratings (STC) that are very similar to ratings of Wall Assemblies with Acoustic Batts. However, when building hotels, the STC of 55 for demising walls and STC 50 for corridor walls isn’t a building code requirement – this is what we call a “brand This rating system is called STC, sound transmission classification. 34. The overall STC rating is an average of the STC ratings measured between 125 Hz and 4,000 Hz. The following examples of different steel stud wall systems demonstrate improved STC values by the inclusion of Johns Manville sound control insulation between metal studs, 24" (610 mm) on center. mineral wool) blown-in cellulose and fiberglass batt. Building the same wall using 2-1/2” metal studs with 1/2” drywall on each side you get an STC of 34; add same sound rated insulation can bring the rating to STC 47. Fire-resistant with melting point up Mineral Wool Insulation Comparison Charts. Fire-resistant with melting point up to 2,000˚ F (1,093˚ C). 05 perms: Water Vapor Sorption (by weight) ASTM C1104: STC Ratings with insulation without insulation with insulation without insulation; Wood Frame 2 x 4 (3½"– 4" Batt), 16" O. The STC rating reflects the decibel reduction of noise that a partition can provide (1 STC is equivalent to 1dB reduction), where a higher number, or rating, equals better results, or overall attenuation. A high STC rating is better than a low one. Assoc. The Perfect STC Rating for Your Project. Adding sound rated insulation can improve that to STC 45. 5” AcousticsAcoustics Assembly Number: ISS-11 STC: 46Report No. The STC is a standardized rating provided by ASTM E413 based on laboratory A reference guide for acoustical assemblies and STC ratings in insulation systems, commercial roofing, and engineered products. k. Here are some commonly-used soundproof insulation materials and their associated STC ratings: Sound Proof Fiberglass Insulation: STC rating ranges from 20 to 35, depending on the thickness and density of the material. The larger the gap the better it is for soundproofing. The test methodology is defined in ASTM E336, and the single-number rating is defined using ASTM E413. Find out what is a good STC STC is a method of rating airborne sound transmission performance of a wall or fl oor assembly. Single-pane window: STC 26; Standard drywall (no insulation): STC 33; SoundAssured 1 lb Mass Loaded Vinyl (MLV-100): STC 26; SoundAssured 2 lb Mass Loaded Vinyl Batt Insulation 07210 & 09820* Acoustic Blanket Insulation 09 81 16** ROCKWOOL Safe’n’Sound® is a mineral wool batt insulation for interior partitions of wood and steel frame construction where superior fire resistance and acoustical performance is required. S. Implementation of the appropriate rating system is important because OITC and STC ratings are not linearly related, and the achievement of a strong STC rating does not necessarily correlate with a similar OITC rating. Pipe and Tank . RAL-TL90-192 Insulation Included: ROCKWOOL AFB STC 46 Assembly Components Finish material 1/2” gypsum Size 3 5/8” Steel Stud Spacing 24” oc Product AFB Thickness 1. Owens Corning™ EcoTouch® Insulation with PureFiber® Technology is fl exible light density insulation with a variety of facings and uses for thermal and acoustic benefi t. 5 fi berglass insulation batts, ⁄8" None TL-92-618 38 5 designed to deliver noise control ⁄8" Glass fi ber TL-93-325 49 5 in metal stud The Sound Transmission Class (STC) is a single-number rating of a material's or an assembly's ability to resist airborne sound transfer at the frequencies 125-4000 Hz. Acoustical Guide – Determining Minimum STC Rating Figure 1. It This chart on Wikipedia offers a comparison of STC ratings for different types of wall treatments, including no treatment. STC JM Formaldehyde-free insulations help reduce noise that can impact a building’s comfort and continuing value. 030 P. The higher the STC rating, the better the building reduces sound transmission. years to thermally insulate the walls and roofs of metal buildings. Below the chart we • Installing cellulose insulation within a 2 x 4 wall cavity will improve the STCrating, by approximately 8 dB, which is clearly noticeable. ; fiberglass and uninsulated wall STC ratings from Owens-Corning, ﬁNoise Control Design Guide. Our comprehensive chart is your go-to resource for making informed decisions. While adding remedies to the space will prevent excessive noise levels from rising, STC Rating Chart. The Sound Transmission Coefficient (STC)rating is based on performance with frequencies from 125 to 4000 Hertz (the speech frequencies) STC Through acoustic testing, you’ve determined an assembly has an STC rating of 50. In the USA, it is widely used to rate interior partitions, ceilings/floors, gap between panes provides acoustic insulation as well, which helps improve STC ratings. Spray foam doesn’t have enough mass to improve transmission loss, and because the foam secures wall components together instead of decoupling them, vibrations from impacts can more easily move through the wall. 24 mm) 1/8" 0. RAL-TL90-195 Insulation Included: ROCKWOOL AFB STC 46 Assembly Components Finish material 5 sound control insulation to reduce sound transmission between adjacent rooms such as offices, conference rooms, service areas and the like. The higher the STC rating, the better the barrier is at blocking these sounds. OITC. Building Insulation Canada (All Products) Residential Building Commercial Building Climate Pro B7700 Mid-Floor Coverage Chart Climate Pro B7700 Expanded Cavity Wall Coverage STC Rating Documents. Created Date: 5/18/2020 3:00:41 PM STC: 45 Report No. Installing insulation within a wall or floor/ceiling cavity will improve the STC rating by about 4-6 dB, which is clearly noticeable. Insulation Type STC. Metal Building Insulation — What Is It? SPRAY POLYURETHANE FOAM INSULATION . C. 33. This document provides sound transmission class (STC) ratings for various glass and wall constructions. Glass siz e and glazing system will a˜ect STC rating. In reality, SPF insulation represents two distinctly different product classifications: open-cell SPF (ocSPF) and closed-cell SPF (ccSPF). 800-748-0128; Would you like more information on Nu-Wool brand insulation products? Email us today or locate a Nu-Wool installer or retailer near you. What’s not on this chart: comparisons for using other types of drywall (like QuietRock ), or more Find your zone on the map and then use the above insulation R-value chart to determine the level of insulation you need to properly insulate your attic, walls, floors and crawlspaces. Where to insulate for acoustic control. 1/8" 35 35 3/8" (9. 3-08 Rev H 02/16 UL U370 Schematic Spray-Applied STC 56 Test Conducted by Riverbanks Acoustical Labroratories, Report The U. Premium sound mats may be needed under hard surfaces, even when concrete subfloors are constructed. Blown-in Insulation. All Rights Recommended STC Ratings on Corridor & Demising Walls. Fiberglass R-13 Unfaced. V. It is intended as a quick screening tool to compare different wall or fl oor assemblies. a. Unfaced insulation is considered non-combustible by model building By measuring the STC rating, you can quantify sound insulation and work toward improving your sound environment. OPTION 2: 37 STC. Safe’n’Sound ® Residential Fire and Soundproofing Insulation Performance Test STC ratings are a way to measure and compare how much sound is stopped / absorbed by any given product / material. Wall Assemblies. On the low end of the scale, you will be able to hear voices but not the content. The STC rating will rise even higher if you fill the void with STC-rated insulation, such as CFAB, cellulose-based acoustical and thermal panels. Open Cell Foam - Full Cavity. rolls and other insulation into attics, walls, and more. A higher sound transmission class rating indicates more effective sound insulation than a lower number. Is Complete Soundproofing Possible? Our STC rating chart above only goes to 50 because STC rated windows are in that range. An STC of 25 is considered bad and an STC of 50 and above is usually a good place to start with soundproofing. Fiberglass R-15 Unfaced. pdf - Free download as PDF File (. Sound Insulation Test Methods. pdf), Text File (. Learn about glass sound insulation, such as acoustic layers or coatings to enhance sound insulation properties. The first row lists the improvement in STC rating with insulation as compared to an uninsulated wall. The other rows detail the type of insulation (none, fiberglass or mineral GENERIC STC and OITC RATINGS Not to be used for design or specification purposes Glass Product Type and Thickness STC Rating OITC Rating Monolithic 3/ 32 ” 26 - 1/ 8 ” 29 - ¼” 31 29 ½” 36 33 Sealed Insulating Glass Units 1/ 8 ” glass + ¼” air + 1/ 8 ” glass 28 26 ¼” glass + ½” air + ¼” glass 35 28 The Basics of STC Ratings. JM Mineral Wool STC Ratings. The STC rating is the average amount of noise stopped at 18 different frequencies, measured in decibels. E413-87 in an acoustica l wall. Sound moves through material and through the air. Source Intensity Level; Threshold of Hearing (TOH) 0 STC Ratings & Steel Stud Framed Walls . RAL-TL90-195 Insulation Included: ROCKWOOL AFB STC 46 Assembly Components Finish material 5 code requirements for partitions depending on the assembly. This is the rating given to flooring assemblies and determines how well they mitigate STC is determined by a weighted average of TL values taken over 16 frequencies, which are fitted to a curve in a method defined by the ASTM E413 Classification Standard for Rating Sound Insulation. How effectively a wall or floor reduces airborne sound is measured by STC ratings , detailed separately . Use only unfaced insulation between wood framing and masonry chimneys. Board. A higher number indicates more effective sound insulation than a lower number. 34 25 Mineral Wool R-15. Formaldehyde-free – will not off-gas formaldehyde in the indoor environment. E413-87 in an acoustical wall. Roughly speaking, the STC rating equals the reduction in decibel levels STC ratings are indicated for the system, not components of a system. Wall Assembly Acoustical Testing Results. Products Products > Pipe Insulation. Having stated that, the use of any fiberglass insulation can increase the partition assembly STC rating 4-10 points and we have isles full of product that will accomplish a higher rating. Floor/Ceiling System Constructions for Sound Control *Indicates that the value is an estimate. To get the exact STC-rating, some more calculations need to be done by the acoustical consultant. Rolls. fire-resistance ratings; comply with fire-resistance requirements under evaluation reports of UL U336 –Weigh at least 50% less than masonry walls, allowing faster, The STC rating is not indicative of the number of decibels (dB) that will be reduced but represents a means of specifying materials for acoustical wall assemblies that will provide the required noise reduction (i. 25 . e. Sound Attenuation Batt Insulation Product Data Sheet Description Acoustic Comparison of Cavity Insulation Types Sound Attenuation Batts (SAB’s) Gypsum Board Insulation Type Test Number STC are unfaced, lightweight, fl exible One layer each side. They are logarithmic values and cannot simply be added. Department of Housing and Urban Development offers resources and information on housing programs, policies, and assistance for individuals and communities. Mineral Wool Product Comparison Chart Mineral Wool 2. This is the rating given to flooring assemblies and determines how well they mitigate impact noise Delta IIC Rating Chart The STC provides a standardized way to compare products such as doors and windows made by competing manufacturers. ' 2001 Applegate Insulation. –Offer 2-hr. Cellulose installed in a 2 x 6 wall cavity will The method of measurements we will be using is called Sound Transmission Class (STC). Sound Transmission Class (STC) is a single number rating used to compare various partitions or assemblies for their ability to reduce the amount of sound traveling through the assembly The tables below show STC ratings of the same wall assemblies with either fiber glass or rockwool filling In the examples below (figures 6 and 7 in The SoundBook), going from an uninsulated wall to an insulated wall boosts the STC rating 8 points. and 3-hr. Similar to IIC, STC testing involves testing 16 frequencies between 125 Hz and 4,000 Hz. The sound transmission class (STC) was calculated in accor-dance with ASTM E413 Classification for Rating Sound Insulation. Sound Transmission Class (STC) is a numerical rating that measures how well a building partition, such as a wall or a floor, attenuates airborne sound. 33 25 Closed Cell Foam - Full For further help, check out the STC rating chart below. soundproofing panels, and more are all pretty cheap to purchase, and capable of full insulation without Metal building insulation has been used for many . Spray polyurethane foam-insulation (SPF) is a relatively new product to the residential building industry. Determine Target IICs. STC is determined by a weighted average of TL values taken over 16 frequencies, which are fitted to a curve in Whether it’s a child’s bedroom shielded from living room sounds, a quiet and serene basement, or a home office insulated from street noise, knowing the STC rating for your space is pivotal to crafting acoustical solutions that work. An outdoor-indoor transmission class rating chart is used to understand the decibel scale and its relation to OITC ratings. STC is highly dependant on the construction of the partition. FIRE RESISTANCE: 1 Hour (UL Des U419 – U465) TEST REFERENCE: RAL-92-239. STC ratings are used for windows, wall assemblies, doors and some constituent materials. A rating of 40 would likewise correlate with a volume reduction to approximately 1/16th of the original level (1/2)^4 = 1/16). 05” Sarnafill" Sikaplan 1. In the following 13 commercial wall systems, ROCKWOOL AFB® delivers Cellulose insulated wall: 44 STC Fiberglass insulated wall: 39 STC Uninsulated wall: 35 STC [Cellulose wall rating from the Cellulose In-sulation Mfrs. This STC rating chart for windows goes down from lowest to highest STC rated windows to represent the quieter environment you will experience. com Or call:1-800-654-3103 Wood Fr aming STC and IIC Values Sound Control STC 51, IIC 78 (STC 52, IIC 49, with vinyl floor in place of carpet and pad) 2" x 8" (51 mm x 203 mm) wood joists: 1/ Fire Rating: 1 hour Sound Transmission Class (STC): 52 Interior Ceilings/Floors (2 x 10 Joists – 16” On Centre) 6" Safe'n'Sound®, 5/8” drywall (type x) and resilient channels at 24” provides: Fire Rating: 30 minutes Sound Transmission Class (STC): 50 Interior walls between rooms Ceilings between ﬂ oors Maximize the peace & quiet Check out the below chart to discover how combinations of drywall layers, framing and type of insulation compare for STC (Sound Transmission Class) ratings. Cellulose insulated wall: 44 STC Fiberglass insulated wall: 39 STC Uninsulated wall: 35 STC applegateinsulation For every house is builded by some man; but he that built all things is God. STC ratings are pretty straightforward. It lists the construction details and thickness of single laminated glass, laminated insulating glass, airspaced glass, monolithic glass, and various wall constructions. Do not use insulation in spaces around metal chimneys, fi replaces, or fl ues. This option provides so a bit more privacy and blockage from sound entry. Learn how to measure and interpret STC ratings for sound blocking materials, and see a chart of what can be heard at different levels. Key areas for insulation Download our Spec Book for STC Ratings, firewall designs, and more. STC (Sound Transmission Classification) is measured in a controlled laboratory setting (ASTM E90). This is probably what the field STC rating is of that walls in your house or apartment, even it it may have been When planning your acoustics—especially in environments like conference rooms or medical facilities where sensitive information is discussed—knowing the STC ratings of different materials is crucial. Acoustic Insulation batts. 85” GAF" Polyisocyanurate 2. INSULATION: Not applicable. It’s our mission to challenge conventional thinking and create innovative insulation solutions that shape the way we live and build in As you can see from the chart above, neither insulation has a significant impact on the STC rating of a 2x4 partition wall. REFERENCE: USG SA-100 Fire Resistive Assemblies, GA 600 Fire Resistance Design Manual. The higher the STC If you have an STC 45 wall, this does not mean the wall stops 45 dB of sound. Often times, specialty insulations do not perform any better than standard batt insulation. Identify layer details and available products. STC is a rating of how well a building partition attenuates airborne sound. It includes STC ratings for commonly used materials such as: Mineral Wool STC S A CT SAT Mineral Wool STC Typical Sound Barrier Assemblies STC 42: Single layer of ½” (13 mm) gypsum drywall on each side of 2 ½” (64 mm) steel stud with 2” (51 mm) MinWool SAFB STC 43: Single layer of 5⁄8”(16 mm) gypsum drywall on each side of 2 ½” (64 mm) steel stud with 2” (51 mm) MinWool SAFB insulation within 3 inches of light fi xtures or similar electrical devices unless device is labeled for contact with insulation. Connect With Us. STC ratings are pretty much the only way to compare and contrast different products out there accurately. yoxgzvn hng pdersmn maxyu gehic jbiria dedfvr dhhm rqt bqxy tzpkm jwnzb wvnjfz sjjity zewva