Green Glue

[aud19]

Avare,

I don't have any "opinions" of it. I honestly wanted to know how he felt about the product. I'm just curious as to which products and methods offer the best value/dollar. I will not be offended if you don't like the product, I'm just looking for information

So the reasons you don't like QR is the weight and cost then? Is that right?

[aud19]

Originally Posted by krasmuzik

QuietRock is sheet rock sandwhich with viscoelastic glue

GreenGlue is viscoelastic glue that you sandwhich between sheetrock.

The only difference is who makes the sandwhich, the price you pay, and the effectiveness of the glue.

See, now I didn't know this, that was quiet helpful I can guess buy your remarks that you feel the "effectiveness" is better with GG and that obviously doing the sandwiching yourself lowers the costs.

[krasmuzik]

They also sell QuietGlue if you want to DIY - but I think Brian is professional enough not to do a public head to head and let his product speak for itself.

[1st Cav]

Well this is my 2nd post i believe and now that im in the beginning stages of having my home built i figured that its time to start asking questions. Alot and I do mean ALOT of my potential questions and concerns have been adressed in this forum by doing an enormous amount of searching and reading (about 1 years worth). Getting to the point, Ive read about all of the soundproofing techniques being used by many to seperate their HT from the rest of the home. My concern is similar but a little less intense (for now), my "theater" will be in a 20x16 step down bonus room above my garage. I want to keep all escaping sounds to a minimum due to my 3 year old daughters room being across the hallway (maybe 4.5 feet from door to door) along with the master bedroom and 3rd bedroom/playroom. Of course I wont be watching extremely loud movies after she goes to bed but the concern is still there. Will adding another sheet of drywall with GG between, along the hallway wall and possibly the rear wall help enough to calm some of the excess sound thats bound to escape? I also plan on buying a solid core Safe-N-Sound door as ive read that it does help some, but im interested in other low cost (i know thats a subjective issue) techniques to consider. Ive read about RSIC and things of that nature but i have a strange feeling that once i start considering some of those things my initial HT budget is going to explode. If anyone in the world knows about the continuing pursuit in HT excellence you guys do. If it means anything the gear i plan on purchasing to complete everything is : Pioneer 1015 , Oppo dvd player, 7.1 Ascend setup 340's across the front HTM 200's side and rear, Sanyo Z3 projector, DIY screen (MMud?), SVS PB12isd (2much for the room?). Well if ive left out any important info that would make answering my question easier please let me know. I'll try to post a layout of the room tonight when i get off of work.

Thanks in advance,

1st Cav

[1st Cav]

Oh and my preferences are 80% movies 20% music. Ive read that the garage door may be an issue to consider, if it were you and you had a chance to buy a particular garage door system which would you buy? In case it wasnt clear, im looking a for a quiet system that wouldnt cause too much noise above in the bonus room.

Thanks again

1st Cav

[1st Cav]

As promised here is a layout of the room showing both the 3rd bedroom/playroom and my daughters bedroom, well some of it anyway. I guess its more to the left than I previously stated but still at least 4 1/2 feet from door to door.

[1st Cav]

Sorry im trying to get to 5 posts so i can post a link

[1st Cav]

Finally!! The illusive "link"

http://pg.photos.yahoo.com/ph/firstc...cf.jpg&.src=ph

[Brian Ravnaas]

as folks commented on above, Quiet Rock and Green Glue operate on the same basic principle - viscoelastic damping.

as such it is not inherently true that Quiet Rock + Green + 5/8" would be superioer to 5/8" + Green + 5/8", other than being heavier (quiet rock Serenity is like 93lbs, and normal 5/8" drywall is like 70lbs or so)

but for the cost of the quiet rock you could get 3 or 4 layer drywall/damping sandwiches...


anyway, kraz and DE covered it all above.

[Brian Ravnaas]

Originally Posted by krasmuzik

They also sell QuietGlue if you want to DIY - but I think Brian is professional enough not to do a public head to head and let his product speak for itself.

well thanks, Kraz.

we do have some same-lab 3rd party comparisons of this, but we've never published them.

FWIW, in our tests the Quiet Rock performed almost completely exactly, perfectly the same as it did in tests they've run, a nice tribute to the consistency of theirproduct, perhaps. Also to the possibility of repeatable wall testing, and perhaps also to Audio Alloy's gang for running the tests as straight-up as possible.

so a good job to everybody,, lol

[Brian Ravnaas]

Originally Posted by 1st Cav

Well this is my 2nd post i believe and now that im in the beginning stages of having my home built i figured that its time to start asking questions. Alot and I do mean ALOT of my potential questions and concerns have been adressed in this forum by doing an enormous amount of searching and reading (about 1 years worth). Getting to the point, Ive read about all of the soundproofing techniques being used by many to seperate their HT from the rest of the home. My concern is similar but a little less intense (for now), my "theater" will be in a 20x16 step down bonus room above my garage. I want to keep all escaping sounds to a minimum due to my 3 year old daughters room being across the hallway (maybe 4.5 feet from door to door) along with the master bedroom and 3rd bedroom/playroom. Of course I wont be watching extremely loud movies after she goes to bed but the concern is still there. Will adding another sheet of drywall with GG between, along the hallway wall and possibly the rear wall help enough to calm some of the excess sound thats bound to escape? I also plan on buying a solid core Safe-N-Sound door as ive read that it does help some, but im interested in other low cost (i know thats a subjective issue) techniques to consider. Ive read about RSIC and things of that nature but i have a strange feeling that once i start considering some of those things my initial HT budget is going to explode. If anyone in the world knows about the continuing pursuit in HT excellence you guys do. If it means anything the gear i plan on purchasing to complete everything is : Pioneer 1015 , Oppo dvd player, 7.1 Ascend setup 340's across the front HTM 200's side and rear, Sanyo Z3 projector, DIY screen (MMud?), SVS PB12isd (2much for the room?). Well if ive left out any important info that would make answering my question easier please let me know. I'll try to post a layout of the room tonight when i get off of work.

Thanks in advance,

1st Cav

ok, so your theater will be across a hall from other people, that's good.

you still have door-air-door noise paths, and structural paths, those can both cause some problems.

sometimes, the biggest problem with noise in houses is this:

1) all the rooms in the house are the same - i mean have the same construction (like 2x4 wall with one layer of 1/2" drywall on each side)
1a) as a result, all the rooms in the house have the same resonance problems at low frequencies

so

2) the weakest point of the theater wall lets alot of sound in, this sound moves through the structure easily (as common structures aren't very well damped)

then

3) this sound - mostly around the low-frequency resonance of the theater wall, which is the same as the resonance of other walls - easily stimulates the resonances in the rest of the house causing disturbance maybe 3 or 4 rooms away without problem...


so one advantage of almost ANYTHING you do to your theater is at least it's different. even a resilient channel wall (generally not so good for theater applications) will have this advantage: the frequencies where it's weakest won't coincide with the frequencies where the rest of the house is weakest...



i'd recommend changing the construction of your room to not fall into this matched-ersonance trap that can really cause some almost humorous situations where, literally, 3 rooms over and 2 rooms up the kids get woken up by subwoofers.


adding GG to the hall and/or floor of your theater -to- be will massively reduce structural sound transmission. it will also change the nature of those walls.

adding clips to the walls will change the nature, and reduce structural transmission of wall-to-structure above the point where they are an effective decoupler (determined by depth of cavity and mass on the clips).

really, your situation is one where you could have success in many ways, and i feel that either of the two you mention are among them.

the doors will matter, of course, and check out zero international for some high-performance seals.

[beatboy77]

Due to budget constraints, I will only be able to have one layer of 5/8" drywall. I will also be going with Atlantic Technology System 20 THX In-Wall Speakers. If I were to apply Green Glue to the studs before putting up the drywall, would I experience a sound improvement? Also, would the GG help secure some of the bass from the in-wall speakers? Thoughts?

~Josh

[Brian Ravnaas]

Originally Posted by beatboy77

Due to budget constraints, I will only be able to have one layer of 5/8" drywall. I will also be going with Atlantic Technology System 20 THX In-Wall Speakers. If I were to apply Green Glue to the studs before putting up the drywall, would I experience a sound improvement? Also, would the GG help secure some of the bass from the in-wall speakers? Thoughts?

~Josh

Josh,

Green will help when applied to the stud edges, but this won't be remotely the effect of Green between layers.

The best answer that i can give for this is yes, it's worth it. it's not much area to cover, so cost is low, and it will give you something.

but neither GG on studs nor anything else just appleid to studs now or ever (where the drywall is still screwed to the studs) will truly make a paramount change in wall performance. you'll get improvement, but you won't get a "Green Glue wall", so to speak.

but, then, you won't break the bank, either.

Brian

[kromkamp]

beatboy77, if drywall prices are similar down there to up here, 5/8" drywall commands a 50% premium in price over standard 1/2". So, for only a little bit more money you could get two layers of 1/2".

Of course, this would require more GG but even at 50% coverage its works quite well.

[chiltown]

Any thoughts on the effective of applying acoustical caulk to the studs then drywall / GG / drywall?

Curious if anyone has tested the effect of acoustical caulk sandwiched between two layers of drywall?

[gregavi]

2 Questions: Are two layers of sheetrock with Green Glue between more or less effective than one layer of 1/2" soundboard under 5/8" layer of sheetrock? When using GG, is it more effective using different thicknesses of Sheetrock (one 1/2" one 5/8")? Thanks.

[Dennis Erskine]

1. Sound board is worthless in this application. Green Glue with two layers of drywall by far exceed what soundboard/drywall will do (due to mass and damping).
2. I don't know what Brian has found out in the labs; but, I find the damping more effective as 1/2 over 5/8 (you do loose a bit of mass that way, however).

[gregavi]

Originally Posted by Dennis Erskine

No...
"two sheets of _______ " fill in the blank.

According to the Audio Allow website, when asked about using soundboard, their answer is: No. The “sound board” is not rigid and dense enough to work well. You should substitute the soundboard for drywall.

My point is: Dennis’ “fill in the blank” is not necessarily true according to them.

Here’s my plan, and please improve or correct if not a good plan:

Staggered stud wall / 1/2” soundboard glued & screwed to studs / ½” sheetrock / GG / 5/8” sheetrock taped and textured.

[Dennis Erskine]

I don't understand the 'fill in the blank' thing; but, I wouldn't waste a dime on the sound board.

I see you are 'texturing' the wall ... I hope you plan on acoustic treatments in the room as well.

[gregavi]

I was just pointing out that the manufacturer recommends, I believe, only sheet rock and plywood. To me "two sheets of _______ " fill in the blank, means: 2 sheets of anything.

I find it hard to believe that soundboard is worthless in this application.

Yes I will be using some sort of acoustic treatments in the room. I just don’t know what yet.

Thanks Dennis for all of your expert advice. It has been so valuable to me and to others I’m sure.

[Brian Ravnaas]

Originally Posted by chiltown

Any thoughts on the effective of applying acoustical caulk to the studs then drywall / GG / drywall?

Curious if anyone has tested the effect of acoustical caulk sandwiched between two layers of drywall?

the best performing caulks in this regard will be solvent based oozie-goozie sealants such as Tremco acoustic sealant or Quiet Seal

I've tested a sealant or two. it is overwhelmingly unlikely that a sealant will make an ideal damping material, for reasons that i'd prefer to not discuss, as they involve the nature of what is best for CLD in walls and what is best for sealants. One glaring contrasting factor at work.

[Brian Ravnaas]

Originally Posted by gregavi

I was just pointing out that the manufacturer recommends, I believe, only sheet rock and plywood. To me "two sheets of _______ " fill in the blank, means: 2 sheets of anything.

I find it hard to believe that soundboard is worthless in this application.

Yes I will be using some sort of acoustic treatments in the room. I just don’t know what yet.

Thanks Dennis for all of your expert advice. It has been so valuable to me and to others I’m sure.

i'd recommend MDF over plywood. For reasons of mass, cost, and flatness.

i discussed this in another thread a moment ago, and i pitter-pattered around the soundboard commentary a bit.



the thing that you have to remember about soundboard is first, it ahs the greatest marketing name in the history of products. Second, from the inception of its use as a sound isolation product, it was backed from up on high by a huge, huge industry (the fiberboard industry)

i quote David A Harris from his very nice book "Noise Control Manual for residential buildings)

"In the 1960's the Insulation Board Institute (IBI) begal searching for new product uses for wood fiber insulation board. Someone must have said "hey, that looks like it has acoustic properties." Since the base board had been used for making wood fiber ceiling tile, this was a logical conclusion. Realizing that partitions have better sound transmission loss characteristics when a sound-absorbing material is included in the core, the industry scrambled to prove the theory. Hundreds of tests by manufacturers and IBI ensued. "

"researchers quickly found that sound-deadening board provided significant STC improvement only when the partition had staggered studs or a resilient mounting. It worked well on steel studs since they are inherently resilient. However, merely nailing sound-deadening board as an underlayment to gypsum wallboard was not acoustically worth the effort"

"additional research indicated that a resilient effect could be created by adhering the outer layer of gypsum wallboard to the sound deadening board by laminating with strips of joint compound. Tests demonstrated that the location, size, and character of the lamination strips were critical to the improvement of STC. For example, the best STC values were obtained when the adhesive was still wet - obviously not acceptable in practice, and when the adhesive was located midway between the studs. The effect was to make the board act as a "leaf spring" and thereby provide the resilient mounting needed."

and then offers "unfortunately, marketing efforts were so effective with this magical new product called "sound deadening board" that the contractors thought it would solve all their acoustical problems. Advertising failed to emphasize the "small print" about specialized construction details. Since contractors did not want to hear all of the conditions, many buildings were constructed with sound-deadening board nailed in place just like sheathing. STC values were totally lost. Manufacturers did not attempt to correct the wrongs in spite of warnings by their research engineers because it could mean lost business opportunities. This shortshighted and misleading marketing practice was promulgated through efforts by the IBI which inundated the industry with "technical literature" and articles in construction trade journals."

there, that is the entire section between and after my original quotes. The comment about resilient mounts relates, i believe, to the boards sound-absorption properties. -vs- an empty cavity this is an advantage. it does not state comparisons to an additional layer of drywall were favorable.


1/4" drywall was marketed as a sound isolation product at one time as well. used in manners similar or the same to soundboard - glue heavier drywall only to the area between the studs, and let it float on the flexible 1/4" board. None of these systems would ultimately have proved effective if the STC system extended to 30 or 50hz, but since STC goes only to 125hz, sometimes you can move a problem just under 125hz and achieve large STC gains....

i'll cease my blabbing, but simply summarize that i don't think soundboard in any configuration could ever be demonstrated to have a demonstrative full-bandwidth value, previous comment about the screw-to-the-soundboard-but-not-the-studs notwithstanding. i question the legality of that assembly in fargo, but i've never asked. and i offer that in the end i doubt full-band tests on such an assembly exist, and i wouldn't hold my breath for it to have a transformative effect on the overall performance, although perhaps a subtle one.

[Dennis Erskine]

I find it hard to believe that soundboard is worthless in this application.

Some felt the same about the earth being round. You can do alot better for yourself; but, you asked the question, you got the answer, and debating it with me won't change my answer unless some certified tests come along (they won't) that would prove otherwise to me. But, hey, it's your room and not mine. Have fun!

[Brian Ravnaas]

ok, based on the NRC's test TL-93-190, which has

5/8"
soundboard
2x4 wood studs with fiberglass
soundboard
5/8"

compared to the same lab, same time-period test of single 5/8" on each side of a nominally identical set of studs and insulation and so forth. The soundboard test is found on page 250 of the document IR-761, the regular drywall is found on page 82 of the document IR-693... look 'em up yourself if you please, at www.nrc.ca

Adding the two layers of soundboard under the drywall yields a net gain of ~4.2 dB on a demanding theater curve that i like to use. This is for calculated A-weighted sound reduction in dB.

For a European standard, a noise curve outlined by one Tennekes, the predicted gain is about 4.9dB.

STC went up by 8 points for adding the soundboard to both sides.


For reference, adding a second layer of drywall to each side (nominally this almost doubles mass), would be expected to yield 4.5-5dB of net gainsn on either of the two curves above based on historical measurements.

you would anticipate about 6 STC points of gain for doubling the layers of drywall.



This is the only non-audioalloy full band soundboard test ihave ever seen, it does not imply that it outperforms just adding drywall. You could argue that is has pound-for-pound merit, as the relatively small mass that it adds would be expected to yield only ~3dB for mass alone.

The tests we commissioned were on a lighter soundboard (the NRC's board was about 35 lbs/sheet for 17mm board, ours was ~20lbs/sheet for 1/2"), and the gains were inferior to adding drywall.


Think about it in terms of the five basic principles.

1. mass. it's far ligher than drywall
2. decoupling. just screwing it to studs under drywall doesn't yield decoupling
3. absorption. relative to an empty cavity it might have some benefits, but it's absorbing capacity is dwarfed by insulation in the cavity
4 &5. resonance/conduction - the two principels defined by damping - it is superior in damping to any other common building material, but the overall level is still modest.

[BasementBob]

Brian:

The soundboard test is found on page 250 of the document IR-761, the regular drywall is found on page 82 of the document IR-693

I found the IR-761 pg 250 a couple of days ago, but I couldn't find a corresponding no soundboard wall so I didn't post it.

Good show on the IR-693 pg 82.

EDIT: Are you sure that's the right doc and page?

[Brian Ravnaas]

hi bob

page 82, figure 9, two are wood stud sets in the same configuration as used for the soundboard, but with single 5/8" drywall

tl values discerned with ruler, values used given below. "vertical" was the chosen comparison set as that is what is stated in the soundboard test.

frequency horizontal vertical
50 22 22
63 19 16
80 14 13
100 11 13
125 19 23
160 30 31
200 30 35
250 33 40
315 35 38
400 37 39
500 40 41
630 43 42
800 46 46
1000 49 49
1250 49 50
1600 46 48
2000 38 40
2500 38 37
3150 43 40
4000 48 45
5000 52 50

[gregavi]

Originally Posted by Dennis Erskine

Some felt the same about the earth being round. You can do alot better for yourself; but, you asked the question, you got the answer, and debating it with me won't change my answer unless some certified tests come along (they won't) that would prove otherwise to me. But, hey, it's your room and not mine. Have fun!

I didn't write that I didn't believe it, Dennis. I wrote that it is hard to believe. Big difference. I wasn't debating it either. It is hard to believe because anything is better than nothing, it would seem.

[krasmuzik]

It might be hard to believe that a large manufacturer wants to make more of the same stuff - so they come up with dubious uses for stuff - knowing that they can get the high school drop out contractors to install the stuff - being that they already know how to install their other stuff. Hard to believe indeed!

[BasementBob]

gregavi:

It is hard to believe because anything is better than nothing, it would seem

That's not always true either. Sometimes adding things is bad.
For example it's fairly easy to add a floating floor which amplifies the noise into the room below, at least at resonance frequencies.

It's not just Brian and Dennis and David A Harris that dislike soundboard. There's also Rod Gervais (a VERY practical professional) and Eric Desart.

Rod Gervais's objection is centered around that there's not any proof that it's better than what the soundproofing world is doing now, so using it isn't engineering, it's prayer. If you want advice, trust the labs.

There was a time I wondered how it performed in moisture or fire -- but these days I just ignore it completely as a useless product.

Someone once explained the physics of soundboard. As I recall it behaved
a) a bit of decoupling - but very very very little
b) a bit of damping - but not very good at that
c) a bit of mass - but not much of that
d) a fair bit of absorbtion, the amount being dependant upon the kind of soundboard (the ones with the holes absorb more) -- but less than fiberglass of the same volume
e) all at a relatively high cost compared to the installation costs of drywall

(Hmm, just noticed Brian said almost the same thing above)

So the bigest (ha) effect of soundboard is from the extra absorbtion, and by its increasing the cavity depth between the drywall.


Frequency 1G16+Soundboard(IR761pg250) NoSoundboard(ir683pg82) 1G13bothsides(ir761pg22) 2G13bothsides(IR761pg26) - the right four columns in dB TL (transmission loss)

50 Hz 22.7 22 22.3 26.8
63 Hz 16.5 16 18.5 23.1
80 Hz 18.4 13 23.2 26.2
100 Hz 18.7 13 18.1 20.9
125 Hz 31.1 23 13 15.4
160 Hz 34.3 31 12.7 17.
200 Hz 38.2 35 25 30.1
250 Hz 43.9 40 37.9 41.0
315 Hz 41.2 38 35.8 41.4
400 Hz 44.9 39 36.1 47.6
500 Hz 45.1 41 39.4 48.1
630 Hz 49.6 42 39.4 50
800 Hz 52.2 46 44.2 53.9
1000 Hz 53.4 49 46.7 56
1250 Hz 55.1 50 47.4 58.1
1600 Hz 54.5 48 46.8 60.1
2000 Hz 48.9 40 40.2 57.9
2500 Hz 46.6 37 37.4 48.6
3150 Hz 52.0 40 42.5 48.6
4000 Hz 58.3 45 47.8 53.5
5000 Hz 62.4 50 52.9 59.6
6300 Hz 67.7 xx 57.2 64.3

All of these walls are simple single 2x4 studs without decoupling, so they all have MSM resonance dips at frequencies higher than 63hz.
TL above 315hz we usually aren't interested in, since whatever we build will have good TL there. There's a slight coincidence dip in the 2G16 wall (2 layers of 16mm or 5/8" gypsum) at 2800hz but otherwise over 315hz the two layers of gypsum outperform the soundboard above 315hz.
So the more interesting is the 50hz performance where the extra mass of the gypsum is giving us 15% more dB TL, for less money. Provided we don't have a resonance dip, this extra dB TL due to mass should translate from wall system to wall system.
One way to reduce the amplitide (?) of both the resonance dip and the coincience dip is to use Green Glue.
Anything that would lower the resonance frequency is a good thing in walls (double stud increased cavity depth, RSIC, more mass).

[darkman2003]

Why Why Why !!!