How well does QuietRock reduce bass frequencies?

[kasmira]

More mass = less transmission.

Figure out the cost per mass unit, use the cheaper one.

[ErroneousDylan]

You are correct.

However, apparently QuietRock is made out of specifically different material or at least has a combination of different materials in it compared to regular drywall. I'm just curious if the QuietRock material would be more apt to block out lower frequencies than regular drywall.

If there wasn't much of a difference between the two, then obviously I would go for the cheaper choice (i.e regular drywall), allowing me more mass within my budget. On the other hand, if QuietRock really was more effective than basic drywall at smothering bass frequencies then it may be better to just use it.

Thanks for the response.

[Ted White]

At issue is the reliance / capacity of one product to save the day. As Kasmira pointed out, there are more factors required for competent LF bass isolation.

There are now 5 manufacturers of pre-damped drywall. I have consulted with three of them before they launched. All are simply drywall (or thin common cement board) with a damping compound in between. Same as you can assemble on the jobsite.

Kasmira hit it with the direction to go with more mass. That means good old $8 a sheet 5/8" drywall. This will yield a wall (leaf) that is around 4.5 pounds per square foot, not including framing. Pretty substantial. You need very high bass isolation? Add a third sheet of drywall.

Another key point here is that you want to deploy more than just damping and mass. You also want that framing to be decoupled and insert a bit of absorption in the form of standard fiberglass batt. Typically R13.

Don't spend all your cash on any one element. Better to incorporate all 4 elements of soundproofing than to rely on only 2-3. There are also other chices for damping compounds that have been successfully used for a lot longer than the one you mentioned.

[Rod Gervais]

I have examined the test results for their products - and have no doubt that the products work as claimed - however - when you compare the cost of their products to simply adding layers of drywall mass - the drywall far out preforms them dollar for dollar.....

They would have to bring their prices down a hell of a lot before I would specify them on a project of mine..........

Rod

[Ted White]

There ya go!

[ErroneousDylan]

Thanks for the responses, all. As I assume, I think good ol' drywall is the way to go. The QuietRock sound nice but is far too expensive, in my opinion.

[JayBeez]

I went with 2 layers of 5/8" drywall with green glue in between on both the inner and outer leaves. Pretty cheap, and works great. Buy the green glue in the bucket and save $$. Pretty messy though. Considered QuietRock, but it is expensive, and results are mixed.

[Ted White]

You really can't beat the price or performance of a field application of a damping compound. Cheaper and heavier.