Is SONOpan Good For Soundproofing?
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It seems everyday a new soundproofing product is introduced to the internet. Some of these products can be helpful for soundproofing, while many others are simply a waste of money. Today I will go over a popular soundproofing product called SONpan and let you know if it is worth installing in your soundproofing project.
1) What is SONOpan
According to their website, SONOpan is made from 100% recycled wood and 100% natural binders.I am not sure what the natural binders mean, but it might be the glue or adhesive that holds the wood pieces together. The company who makes SONOpan is MSL and they are a Canadian based manufacturing company.
2) How is SONOpan Used
According to their website, SONOpan is used directly on the studs of your walls and ceilings or over your existing drywall to "soundproof" your room. They also have a product called SONOpanX which is meant for floor installations. They claim it mostly helps with impact noise such as footfall noise or bowling balls dropping on a bowling lane, but not so much with airborne noise.
3) How does SONOpan stop sound transmission
Okay here is the real question. How does this stuff work and does it work? Again, according to their website they have trademarked the term "Noise Stop Technology." This means nothing technically, but is a good marketing tactic. Based on everything they say on their website it looks like SONOpan is really good at absorbing sound. This is similar to fiberglass insulation which has high absorption coefficients across the frequency spectrum.
Here is how they say their panels work:
"SONOpan has over 17,000 impressions in both sides of the panel resulting in a varying density throughout. When it comes to soundproofing, each frequency range has a corresponding sound wave where the peaks and valleys of that range are a certain size. The peaks and valleys in SONOpan are what make it extremely effective at soundproofing." - SONOpan Website
Here is where they lose me. Soundproofing is not the same as sound absorption. Soundproofing involves adding mass to your walls, making sure they are air tight, using insulation in your walls, and making sure your walls are decoupled from the outside structure. SONOpan does none of those things.
SONOpan may be good at helping the acoustics in your room, but I don't understand from simple physics how it could help with soundproofing.
Next, fiberglass insulation can absorb frequencies down to 125hz. However, to absorb frequencies in a room below 100hz you need pressure based absorbers like helmholtz resonators or membrane absorbers. A piece of thin wood fiber will definitely not absorb low bass frequencies.
"The peaks and valleys in SONOpan" are what help with high frequency absorption most likely above 500hz. Again, this product may be a good alternative to acoustic panels in your studio, but I would not use it for soundproofing.
4) What are the SONOpan STC ratings
STC or Sound Transmission Class ratings are a way to compare different soundproofing assemblies with each other. The higher the STC rating the better that assembly is at attenuating sound between 125 hz and 4000 hz. This is roughly the frequency spectrum of human speech, but it does not account for frequencies from low bass, kick drums, trucks driving by, airplane rumble, helicopters buzzing, or lawnmowers nearby.
So when we look at STC ratings claiming to soundproof a room we need to be aware that low bass frequencies are not being accounted for. The best way to attenuate low frequencies is to add mass to your assembly.
The best way I recommend soundproofing a wall is to use what I call the double wall assembly. Here is what SONOpan says they get from:
2 layers of 5/8" drywall>wood studs> R13 insulation> 1" air gap > R13 Insulation> wood stud> SONOpan> 2 layers of 5/8" drywall.
image source: SONOpan Website
Notice the STC rating is 68. As a side note, I did not find any lab test results for their STC ratings, which means we are taking their word for their data not an independent third party lab. When I reached out about their lab tests, they responded by telling me SONOpan is not yet available in the United States, which did not answer my question.
Now let's look at the same wall STC rating without SONOpan.
Notice the same wall design without SONOpan gives you an STC rating of 63. Now can you hear the difference of 5 STC points? The answer is not really. STC ratings are not a perfect example of how we perceive soundproofing either, so small differences in numbering at not as noticeable as say an STC of 45 versus 68.
Next, here is another STC chart from a company called The Soundproofing Company. This diagram is from the Soundproofing Company website.
This wall assembly is essentially the same design as the previous two accept that it includes two layers of Green Glue between the two layers of 5/8" drywall. As you can see the STC rating for this wall assembly is 73. This is better than 68 and 63. Again it would be best to double check these STC ratings with the verified lab test data just to make sure the data is accurate.
The key takeaway is that the main thing "soundproofing" all three of these walls is drywall, the airspace, the insulation and making sure it is airtight using acoustic sealant. The Green Glue and SONOpan may add a few STC numbers, but it is not earth shatteringly different.
When it comes to soundproofing there really isn't some secret technology that will suddenly make your sound go away. The design of your walls and ceilings and floors really comes down to some fairly simple design concepts. The use of additional soundproofing products like Green Glue and SONOpan may help a tiny bit, but consumers should really ask themselves if it is truly worth the added cost. The main cost of soundproofing your walls is going to be the cost of lumber, drywall and insulation. These materials will soundproof your wall if you build it correctly. Adding SONOpan seems like a waste of money to me.
As of right now SONOpan costs $29.63 per 4ft x 8ft panel. 5/8" drywall costs $17.87 per 4ft by 8ft panel. I would always use 5/8" drywall over SONOpan because it adds mass. At the end of the day mass will help way more with soundproofing than anything else. Lastly, SONOpan has very little mass compared to 5/8" drywall. 5/8" drywall weights 70.4 Lbs whereas SONOpan only weighs 26 Lbs.
To be completely honest, I don't see how SONOpan soundproofs at all. I could believe that it absorbs sound, but remember absorption is used for room acoustics not soundproofing. I would not recommend using SONOpan and I hope you now have some solid science and facts to prove why you should say no to some flashy soundproof marketing with SONOpan.