Easy Wall Treatment Solution?

[Tonto]

Home depot has this stuff on sale. $135 is pretty cheap for the amount, 128 sq ft. My front wall is roughly 12 ft X 8 ft. Anybody ever use this stuff or test it. Talk about easy to in stall! I could see using it on my entire front wall. I bet you could put it on, and maybe put 2 or 3 layers over that (only 1/4" thick). If not, we should get some of it and give it a go over to see if it's any good. If it works, this would be quite a find.

 

[Kal Rubinson]

What stuff?

 

[Tonto]

Sorry Kal, thought I posted the link!

https://www.homedepot.com/p/Foss-Qu...Acoustic-Sound-Proofing-8PD6H06BQ0D/205181953

Hope this helps!

 

[Tonto]

Nobody has heard of this stuff I guess! I was hoping Kal or MjPoes would have an opinion.

 

[Todd Anderson]

I haven't heard of this stuff.. @MjPoes12... do you have any comments?

 

[Matthew J Poes]

Hi yes sorry I missed this post.

It's acoustic carpet with a backing. It's not anything great to be honest. It's a way to get a lot of absorption cheap but...only at high frequencies.

I really question any claims of soundproofing. I'd expect no more than 3db of additional isolation from the covered wall.

A version of this stuff is widely used in commercial offices and has been for decades. It's a great commercial option when minimal absorption is needed to just get echo under control. It's cleanable and durable.

I don't know that I can be of much more help other than to say personally I wouldn't use it. If you plan to supplement with some deeper 4" and 6" panels in key locations then it might be ok.

 

[Matthew J Poes]

https://acousticalsolutions.com/product/crosspoint-sound-absorbing-fabrics/

Here is a similar product with absorption values. Has a similar NRC of .2 vs .25. For a point of reference gypsum alone actually measures around .15 or so. This stuff adds HF absorption to a gypsum wall and very little midrange over gypsum alone. Neither absorbs a lot of mid-bass. Gypsum on a compliant or resilient mount actually absorbs a good bit of bass on its own (that's really more an aside).

 

[Kal Rubinson]

Here's a clear discussion of NRC which is a measure of sound reflection/absorption but, as a single number, does not account for the effect at a wide range of frequencies. Probably priced for what it does.

https://www.soundacousticsolutions.com/news/what-is-nrc-7702

 

[Tonto]

I have always assumed that the goal on the front wall was primarily absorbing the higher frequencies (by no means am I an expert). I have always planned on using 1" OC ridged fiberglass on the entire wall. Thicker in the corners...expensive...I was hoping this would work and save me some $'s, especially if I used 2-3 layers coupled with a diffuser mounted on the wall behind each speaker. Do you think the 1" OC would preform that much better?

 

[Matthew J Poes]

Here's a clear discussion of NRC which is a measure of sound reflection/absorption but, as a single number, does not account for the effect at a wide range of frequencies. Probably priced for what it does.

https://www.soundacousticsolutions.com/news/what-is-nrc-7702

Hi Kal thanks for sharing the link. I think it's important to add to that description that an NRC value is an averaged absorption value derived typically using a random incidence method. Such a method requires a true reverberant field and this is directly measuring the removal of sound energy over time. This doesn't translate to reality very well in a small room with no reverberant field. A panel with an NRC value of 1.0 at all frequencies would not absorb 100% of the incident sound contacting it, or anywhere close to that. A direct Measurements would not only show that the sound level of the reflection is only reduced by maybe 6-10 dbs (a bit more at some frequencies of course) at most frequencies, but the absorption would also be fairly uneven.

I only mention this because knowing this helps explain why very thin panels like wall carpet aren't great for theater or studio acoustics.

Attached find an in situ measurement I took. Not clean to very low frequencies but still shows a bit of what is going on.

PS. Kal I very much love your writing for stereophile. You, Fremer, and Atkinson are why I still subscribe to stereophile.

Here is a 5" fiberglass panel with a decent airgap and a 40 degree angle of incidence.

 

[Matthew J Poes]

I have always assumed that the goal on the front wall was primarily absorbing the higher frequencies (by no means am I an expert). I have always planned on using 1" OC ridged fiberglass on the entire wall. Thicker in the corners...expensive...I was hoping this would work and save me some $'s, especially if I used 2-3 layers coupled with a diffuser mounted on the wall behind each speaker. Do you think the 1" OC would preform that much better?

You want to absorb low frequencies just as much as high. The difference between 1" OC703 and .25" wall carpet is substantial. Still I think personally that neither is a great plan. My suggestion would be to go with 2"-4" on the front wall behind the speakers and proper bass traps in the corners. While costly there are ways to make this cheaper. For example cheap rockwool or fiberglass wall insulation works fine (better even) in thick corner traps than does something like OC703. Curtains work as well or better than OC703 when given a 4" airgap and are cheaper.

If you live near a Menards they sell Corning Safing insulation. It's 4" thick rockwool, dense (6lb density) and costs something like $30 for 4-5 pieces. I use this in my panels, it's cheap and great.

The wall behind the speakers causes a significant bass problem due to speaker boundary interference. This is why thick insulation and bass traps are important on the wall.

 

[Tonto]

Thanks guys, I should have known it was too good to be true!

 

[Matthew J Poes]

Thanks guys, I should have known it was too good to be true!

Sorry Tonto. Please don't be discouraged. We can help you get the results you want with nearly any reasonable budget. It just won't be so easy.

I built this giant 24"x24"X36" bass trap for under $50. In fact I want to say that I spent maybe $150 on materials and built two 5" thick 24"x48" panels, a 24"x24"X36" bass trap, and have enough insulation to make a few more panels.




Excuse the mess!

 

[Tonto]

Oh I know. I have a pretty good working knowledge of what I will need to do and some "new" ideas to try out. That product would have just taken a lot of the work out of damping the front wall!

I'm going to try different stuffing in my riser. Think I'll see what happens with fluffy in all the cavities, then rockwool in each outside/wall cavity. The front of each cavity is open with the top of each open at the back, next to the wall with HVAC vents covering the holes. Just to see how it will affect the LF's. Don't expect much difference, but I don't want to just leave it as wasted space either.

I will really appreciate your input when I get back on it.