Our Advice: If you need a temporary booth or a semi-mobile booth then it seems like the pre-fab route would be a good bet even with the limited performance. If you really want to isolate sound then you need to build a booth following the basic principles of sound isolation. Frame a booth with decoupled walls either using staggered stud walls, double stud walls, or resilient sound clipped walls and then incorporate, at minimum, mass through multiple layers of drywall on the outside of the booth and the inside of the booth along with insulation between the stud cavities. The inclusion of damping from Green Glue Compound is popular as well, especially in floors where decoupling is much more difficult.

• Damping adhesive used in pre-damped drywall is not nearly as efficient as Green Glue Compound resulting in lower performance regardless if installation is successful.
• Only one layer of material is hung which increases risk of a faulty installation. Installation installations include requirements to use an expensive acoustical sealant on the perimeter of each sheet before hanging along with thin lead strips behind each joint.
• Pre-damped drywall is very heavy and the most commonly purchased style includes a cement board backing that can really only be cut with a circular saw rather than a razor knife like you can with any standard drywall.
• Labor is saved by not having to apply the Green Glue Compound, but savings from this are quickly lost because of the weight of the material being hung and the difficult in cutting the material.

Our Advice: Green Glue Compound with double layer drywall is roughly 35% less than pre-damped engineered drywall solutions – this includes all materials and labor. The Green Glue Compound solution costs less, performs better, easier to install, and no risk of installing incorrectly unless you forget to apply the glue. Given this, why would anyone use pre-damped engineered drywall to isolate sound? Our experience is that many will try the pre-damped drywall, but few will continue to use the pre-damped drywall out of frustration for the many pitfalls of the pre-damped drywall solution. Boise Idaho Drywall Contractor Services

Our QuietBox solution restores the mass in line with double layer 5/8″ drywall with Green Glue Compound between each layer. And just as important, the entire box is decoupled from the joists using resilient clips with the box being sealed to the back of the ceiling drywall.

Our Advice: You do not have to buy a QuietBox to isolate your recessed light, you can make your own if you want. Any other solution though will not properly address the lost mass from the recessed lighting. If you design your own box then be sure to follow the requirements of restoring ceiling mass, decouple your solution from the joists, and make sure to seal the box to the drywall to avoid sound leaks.

Resilient channel really is not that bad of a product to use in walls. Realistically you can bring up the rating of a wall by a good 12 STC points. Note that there will not be much improvement at all in isolating low frequencies. The STC increase might just be enough for you if you need to block some low level sound transfer such as people talking in the next room, phones ringing, or light TV noise. Resilient channel is difficult to install and nearly impossible for a DIY homeowner to install correctly without prior knowledge of drywall and the common pitfalls of resilient channel. Because of this we would definitely recommend the use of our RC Assurance resilient channel clips. You’ll need quite a few of them even for a small wall, but they are very cheap and they will guarantee a properly installed resilient channel.

Now resilient channel can do well in walls, but it will not do much in ceilings. Ceilings are a whole other beast in the world of sound isolation and the flimsy resilient channel decoupling the drywall by just a 1/4″ adds an insignificant amount of resiliency to a 12″ thick wood framed floor. Airborne isolation will improve with ceiling installation, but not by much. Footfall impact noise isolation will not be affected enough to satisfy the majority of customers.

It’s always good to point out that importance of avoiding installing resilient channel or any decoupled system over existing drywall. This causes all sorts of issues with resonance (triple leaf effect) and the end result is a void gain from using resilient channel. Resilient channel can increase performance in a wall by 12 STC points, but if installed over drywall to cause a triple leaf then the performance will be brought down roughly 10 points. Overall gain will only be 2 points. Resilient channel in a ceiling will only bring up the performance by about 5 points so if you install the resilient channel to cause a triple leaf then you might be worse off from when you started.

Our Advice You can do pretty well using resilient channel in walls as long as you install it properly. Use the RC Assurance to guarantee success or really take your time installing to make sure you do not short out your installation. Installing resilient channel in your ceiling will not provide great results and no real improvement for footfall impact noise. Resilient channel is a decent solution for sound isolation in walls, but there are better products out there that do not really cost more as well as products that have easier, more fail-proof, installations.

Resilient Channel With Foam or Rubber Attached

Some project specs call for resilient channel with a thin foam installed on the channel and/or between the channel and framing. Some manufacturers have put together a resilient channel with foam or rubber pre-attached along with a foam or rubber base to install between the channel and the framing. This seems like a great idea, but in the end all you will end up with is the performance of basic resilient channel. No true sound test would show otherwise.

Our Advice: Do not bother with these types of products. Go ahead and use resilient channel, but do not think that using foam on the channel will actually give you a jump in performance beyond an inaudible 1 STC point gain. The reason why these types of products exist on the market is because it is nearly impossible to make a profit off selling resilient channel unless you are a local distributor. To compete online, companies had to come up with a way to alter the resilient channel to make it more appealing than basic resilient channel.

With that said, including sound board in your floors will have a decent increase in performance. It will not be as significant as QuietGround Rubber Underlayment or Green Glue Compound in your floors, but it will perform noticeably better than just another layer of plywood.

Our Advice: Sound board, and similar sound board type products, are okay for floors, but a waste of time and money in your walls and ceilings. If you want layers then stick with something that is cheap with higher mass like drywall.

Our Advice: Save the cash on the fancy insulation and put it towards products that will provide a much larger boost in performance. Or if you are working on a home theater, get a nicer sub.

The basic design of the clip is familiar with the black neoprene bumper and one screw installation. The performance increase, which is mainly found in the low frequency ranges, is largely attributed to the quality of the neoprene rubber attached to the clip. The Durometer (hardness) of the rubber is 20 points lower than the other resilient clips that incorporate rubber on their clip. That is a very noticeable difference and just part of the equation that helps the GenieClip perform at maximum efficiency. Here is an excerpt from the manufacturer’s site discussing the quality of rubber on the GenieClip:

Importance of Rubber Properties in Performance of the Resilient Clip Technology

Rubber is a superior vibration isolator. In almost every significant application, rubber is chosen to isolate vibrations because of its compression ratio, dynamic and static properties. The dynamic properties of the rubber element of a vibration isolator are affected by its compression ratio, and thus the dynamic characteristics of a vibration isolator depend on the static load.

Stiffness

The stiffness measures the “spring rate” of the rubber. Higher spring rate means a stiffer material and lower overall performance.

Static Stiffness

Under a static or constant load, the stiffness is measured.

Dynamic Stiffness

Tested under a variable load due to the effect of vibration. It is a forced frequency test for resonance at specific frequencies. Natural rubber has the lowest dynamic stiffness of common material.

Result

KINETICS: 21.6 N/MM
PAC: 21.2 N/MM
PLITEQ: 11.3 N/MM

Dynamic / Static Stiffness Ratio

The ratio is a measure of the resiliency of the material. For example, for completely resilient material, the ratio is
1. In order to achieve isolation at lower frequencies, it is important that this ratio be as low as possible. Therefore, ratio closer to 1 means better vibration isolation performance. Most acoustical engineers will specify isolators that have a maximum dynamic to static ratio of 1.4.

Result

KINETICS: 1.29
PAC: 1.34
PLITEQ: 1.19

Force / Deflection Curve

If the isolator is more resilient, typically the acoustical performance will be better. A measure of force versus deflection gives a direct link to resilience at a static loading.

Result

KINTETICS: 19.79 N/MM
PAC: 23.88 N/MM
PLITEQ: 8.95 N/MM

Durometer of Rubber

Durometer is a term for hardness as indicated by the Shore A durometer number. The normal range for isolation materials is 40 to 60+ / -5 as limited by dynamic stiffness. Steel springs for example have a ratio of 1. Dynamic stiffness increases with hardness and in broad terms, the filler ratio of the materials to the rubber content as well as the carbon black reinforcement, plasticizers etc.

Results

KINETICS: 56
PAC: 57
PLITEQ: 37

Conclusion

Based on these results, the rubber stiffness of the Pliteq GenieClip is about 2 times better than the other two materials. Since the dynamic stiffness and dynamic to static ratio control the performance of the clip, especially at low frequencies, it is clear that the performance of the GenieClip will be superior to the other two products.

The above report can be found by opening up this .PDF file: Importance Of Rubber Properties

What The Above Report Means For Your Project

The increase in performance from the GenieClip is most noticeable in the lower frequencies. The GenieClip provides a 2-3 point increase in the lowest of frequencies compared to the most popular resilient clips. The STC rating of the GenieClip is as high as 64 with an OITC rating as high as 49. The GenieClip’s ability to isolate both high and low frequencies make this clip a great option for any project. The quick one screw installation and low profile design will help you get the job done quick without sacrificing too much headroom.

Acoustic underlayment is used anywhere a higher level of isolation is required in both STC ratings and IIC ratings.  The materials used in acoustic underlayment are usually recycled rubber, cork, a combination of rubber and cork, and foam.  Other underlayment includes adding Green Glue between the existing sub-floor and a new layer of sub-floor or “mass-based” rigid underlayment usually made of concrete type materials.  The higher performing underlayment (rubber, cork, or a combination) are usually required in multi-family housing and other commercial applications to achieve a field test IIC rating of 45+ and a lab test IIC rating of 50+.  Most condominium structures and large commercial buildings use thick concrete floors and steel framing so these ratings are achievable with an underlayment of minimal thickness–typically around 2mm depending on the flooring used on top of the underlayment.  For example, tile floors will require a thicker underlayment as they will generate considerably more noise than a vinyl floor or even a hardwood laminate.

Different Ratings For Underlayment

STC ratings largely cover the higher frequencies like speech, radio, and sounds from the TV (not including sub-woofer).  IIC ratings is a way to calculate the level of isolation in relation to impact noise or structure-borne noise which would include footfall, a chair dragging along the floor, or other common noises typically caused by every day living.  The IIC rating is important because a floor can have a sufficient STC rating, say in the low 50′s, but won’t do much at all for isolating impact noise.  With that said, IIC ratings can be very misleading in most cases because it is a rating for the entire system and not just for the material added to the current construction.  Most IIC tests include several inches of concrete, a layer of Gyp-Crete or similar, and usually an acoustically rated ceiling on the underside including either steel stud framing or resilient channel.  So the solution for this dilemma, to cut through the bogus claims of 70+ IIC is to find out the Delta IIC rating.  The Delta IIC rating, or usually written as ?IIC, is a rating for what the material truly isolates on its own.  Like every sound rating the Delta IIC can be misleading as well as performance of a product on a concrete sub-floor will vary from the performance of a product on a wood floor.

If Many Ratings Are Misleading Then What Should I Do?

Unless you can verify the materials used in a test then you can either trust the person trying to make the sale on the product or educate yourself on what type of materials and methods can actually isolate sound.  For walls and ceilings the best way to isolate sound is to decouple the room you are in from the existing structure as much as possible.  The same is true for floors, but the cost of doing this in floors, at least properly, can be ridiculously expensive.  The next best option is to dampen the connection between the flooring and the sub-floor.  To do this you really only have two options.  You can either use a resilient underlayment or add a layer of sub-floor to the existing construction with a damping glue between the existing sub-floor and the new layer of sub-floor.

Using Green Glue To Dampen

Adding the second layer of sub-floor with a damping glue like Green Glue will definitely provide some great results.  The only problem is that installation can be very complicated and limited to certain floor constructions.  One of the limitations is that you can only properly add a layer of sub-floor and Green Glue to the existing sub-floor if the existing sub-floor is wood and not concrete.  This is because the new layer of sub-floor will need to be screwed into the existing layer of sub-floor so that the Green Glue can properly compress between the two layers of sub-floor.  Another limitation of using Green Glue and an extra layer of sub-floor is simply the labor of installing another layer of sub-floor.  It really isn’t much of a DIY project, at least not for a novice, and can be pretty close to impossible to accomplish in a retrofit situation if you don’t have the space to setup a table saw to cut the sub-floor to fit your existing floor.  So adding a layer of sub-floor and using Green Glue is a great option and can be very affordable in comparison to rubber underlayment if all the labor is done yourself or free by someone else.  SIDE NOTE: Have you ever read a paragraph that used the word ‘sub-floor’ more than this paragraph?

Using Rubber To Dampen

Solid rubber is without a doubt the most resilient underlayment available.  In fact, 2mm of rubber underlayment is equal to 6mm of the next best performing underlayment which is cork.  Rubber underlayment usually comes in 4′ wide rolls in either 25′, 30′, or 50′ lengths and 2mm, 3mm, 5mm, 6mm, 8mm, and 12mm are the most common thicknesses of rubber underlayment.  The advantage rubber underlayment has over Green Glue is that it can be used on wood floors, concrete floors, wherever, and installation only involves rolling out the underlayment and taping the seams together.  You can glue it down, but you definitely don’t have to and really you shouldn’t glue it down if you are using a floating floor on top of the underlayment.  Acoustical underlayment manufactured from sustainable recycled rubber composite, offers optimal sound reduction while remaining impervious to the elements for life.  Unlike natural cork, recycled rubber remains permanently resilient and will not embrittle with air exposure.  Recycled rubber underlayment can be used with most all wood flooring installations, including glued down, nailed down and stapled down.  It is also specified for use beneath ceramic tile, cork floors, carpets and a variety of resilient sheet and tile floors.  As is the case with acoustic cork, whenever you are installing flooring by a method other than free-floating, the underlayment must be attached to the sub-floor as opposed to simply laying it down.

Using Cork To Dampen

True acoustic cork underlayment will provide a high level of sound reduction as long as the cork used is 6mm or thicker.  Acoustic cork underlayment is spec’ed for use under all types of flooring including glued, nailed, and stapled down installations.  With some flooring types (typically hardwoods and hardwood laminates) you may need to install a moiseture barrier under the cork.  Most manufacturers will accept a 6mil plastic sheet as a moisture barrier.  Be sure to consult the manufacturer before installing your flooring over cork without a moisture barrier.

Cork is also a very affordable build-up material that can be used to create level transitions from tile, hardwood, and carpeted surfaces.  As with rubber underlayment, whenever you are installing flooring by a method other than free-floating, the underlayment must be glued to the sub-floor instead of utilizing a free floating installation of the underlayment.

Conclusion

The only effective way to isolate impact noise and reduce sound transmission between floors is to use an underlayment that can properly dampen.  Rubber underlayment will always perform better than the rest and also has several other advantages in regards to longevity and providing a quality moisture barrier.  Cork underlayment is a very cheap product that can perform well as long as you have a really thick cork.  A 6mm cork will only perform as well as a 2mm rubber underlayment, but that may be all you need for your project.

Can Joist Tape Isolate Sound?

Not really.  Best case scenario if you were to add the tape to a 2″ x 4″ wall with 1 layer of drywall on each side you will find an improvement of 1 STC point.  This rating is based on an unofficial test performed by someone capable of performing a legitimate test and not just speculation.

Here’s the story for the test mentioned above and a pretty good summary of the world of joist tape sales:

A customer interested in finding an effective and affordable way to isolate sound on his projects contacted a seemingly reputable online sound isolation product provider.  They told him if he added joist tape to one side of his wall and hung just one layer of drywall then he would find an improvement of 10 STC points.  So he followed their instructions and applied the strip, then hung the drywall, and then sealed all the angles and joints with their acoustic caulk.  He ran some tests on his newly isolated wall and received results that provided an increase of 1 STC point.  So he called up the supplier and asked them why it did not work as advertised.  They let him know he needed to add the joist tape to both sides of the wall to achieve the 10 STC point increase.  So he removed the drywall from the other side, added the tape, hung some new drywall, sealed the wall, and ran a test.  There was no increase in STC rating.  He called the supplier and was only able to reach their voice mail and did not receive a return call.  He decided to drop it and moved on to using resilient sound clips in his projects.

Why Does Joist Tape Not Work?

If the tape is intended as a damper then it will not be successful as the tape has no damping properties and the foam material used to make this tape is not considered a legitimate damping product.  If the tape is intended to decouple the drywall from the stud then it will also fail as the joist tape is immediately shorted once the drywall is screwed into the stud through the tape.  So in terms of damping and decoupling, the joist tape simply does not have the ability to perform as a sound isolation product.

Are There Similar Low Cost Alternatives To Joist Tape?

There are some other options that will provide more benefit than joist tape for minimal cost.  The most basic option is using a damping glue on your studs or joists before hanging the first layer of drywall.  The damping glue most commonly sold for this is Green Glue.  There are no sound tests to support the claim that Green Glue on the studs and joists will provide a significant increase in isolation, but this is a method commonly spec’d on commercial projects and the concept is simple/logical.

You may be wondering why Green Glue on the studs would be better than tape on the studs.  The reason for this is because Green Glue is considered one of the best damping products manufactured.  Green Glue will effectively reduces vibrations between the contact of the first layer of drywall and the stud/joists.  Green Glue in no way attempts to decouple the drywall from the stud so the fact that the screw passes through the glue to the stud will not affect performance.  In fact, it will improve the performance of the Green Glue because it will help the Green Glue compress between the stud and the drywall.

Conclusion

Applying any product between your stud or joist and the first layer of drywall will not isolate a significant amount of noise.  Using a product like joist tape or integrity gasket will not provide any increase at all.  If you want to squeeze out a couple extra STC points from your isolation efforts then applying Green Glue to the studs is a real affordable way to accomplish this.  In the end though, decoupling and damping the entire wall or ceiling rather than just the studs is always going to give you the best bang for your buck.

Does the QuietBox Work?

The QuietBox definitely does allow you to use recessed lighting in your ceiling without reducing the acoustic integrity of your ceiling.  The QuietBox is made of 3/4″ MDF which is a very thick and dense material that provides a significant amount of mass to improve isolation.  The product that really helps the QuietBox isolate sound is Green Glue.  The Green Glue is applied liberally at a rate that is the equivalent of 3 tubes per 4′ x 8′ sheet of material.

If you are using double layer drywall and Green Glue on your ceiling then the QuietBox will perform as well as your ceiling.  If you are installing sound clips on your ceiling then the inclusion of the RSIC-DC04 clips will help maintain a consistency in your theme of decoupling.  In terms of sound isolation, think of the QuietBox as an extension of your ceiling.  The level of performance the QuietBox provides will in no way negate the isolation performance of your ceiling.

How Do I Install A QuietBox?

Our QuietBox is attached directly to your joists using RSIC-DC04 clips.  These RSIC-DC04 clips are included with each box and very easy to attach to both the joist and the QuietBox.  The attachment of the QuietBox is very simple, but does require electrical work to bring power to the recessed light.  We can only provide installation help in regards to the box itself.  Please click the link below to review the steps to installing a QuietBox.

READ OUR IN-DEPTH QUIETBOX INSTALLATION GUIDE

QuietBox Product Specs

Recessed Lighting Specified For This Box

We chose the Halo line of lighting products because of the affordability and availability nationwide.  Halo products are available at almost every electrical wholesale supply house and every Home Depot or Lowe’s in the United States.

For 6″ Lighting: Halo 6″ H7ICT and Halo 6″ H7ICAT.

If you do not have the Halo 6″ light that we have specified then make sure your 6″ light fits the specifications of the light to the left.  The QuietBox allows for 8″ of height within the box.  Allow for 1/2″ of this 8″ to remain a gap between the back of the light and the interior layer of drywall.

For 5″ Lighting: Halo 5″ H5ICT and Halo 5″ H5ICAT

If you do not have the Halo 5″ light that we have specified then make sure your 5″ light fits the specifications of the light to the right.  The QuietBox allows for 8″ of height within the box.  Allow for 1/2″ of this 8″ to remain a gap between the back of the light and the interior layer of drywall.

For 4″ Lighting: Halo 4″ H99ICT

If you do not have the Halo 4″ light that we have specified then make sure your 4″ light fits the specifications of the light to the right.  The QuietBox allows for 8″ of height within the box.  Allow for 1/2″ of this 8″ to remain a gap between the back of the light and the interior layer of drywall.