Green Glue or Resilient Channel????

[aertex]

A relatively simple question: if there had to be a choice to be made to use just one of these 2 materials in a home audio room for walls application, and based on benefit of each alone, which would be the best choice?

 

I hope this remains a simple question as I seek a simple (one or other) answer. Please disregard all other permutations and combinations

 

Thanks

Alan

Edited February 21, 2019 by aertex

[davewantsmoore]

1 hour ago, aertex said:

performance

Performance at doing what?

[solman]

I would assume that separation, clips and channel, would do more (sound proofing wise) than dampening, green glue. 

 

I know a fair few people on Avs have skipped green glue due to budget restraints and have just gone with just double drywall and clips / channel.

 

On a side note I know a few guys on Avs have used carpet tile glue as an alternative to green glue. It's significantly cheaper, but there is no solid evidence on how it performs. But in saying that, it's gotta be better than none right? 

[aertex]

14 hours ago, davewantsmoore said:

Performance at doing what?

Oh dear.....I can feel it coming on....

Let me put it another way. What benefit or effect would each have if used alone in regards to acoustic improvement in a room built with std timber stud walls and plasterboard of any type as in Soundcheck, Fyrcheck or std type-as opposed to a room of same construction without either?

 

Thanks Solman

Edited February 21, 2019 by aertex

[davewantsmoore]

8 hours ago, aertex said:

Oh dear.....I can feel it coming on....

When people ask these types of questions they are trying to help you.

Your question isn't as super-simple as you assume....  especially when the question isn't well defined (you will also get vague answers).

 

Later.

[Guest Peter the Greek]

They do two different things. Structural isolation (clips) is first, then mass, then damping in order of priority and performance. 

 

Adding mass and damping is possible after the fact, you cant put clips on once that first sheet goes on.

[aertex]

I fully understand you and respect your knowledge and experience in audio generally. I also fully realize the complexities that the physics behind the question presents. But within the complexities, the physics can be stripped back and intentions considered in a most simplistic form to draw a conclusion

 

This can be one of the biggest problems in the pursuit of a home audio passion where the science and mystics and subjectivities of physics, opinion and personal preference confuse the hell out of most audio punters (like myself) and can result in audio action paralysis. One only has to read one of copious threads on even loosely technical nature and what I describe becomes very obvious

 

I seek to ask this question I have considering its most fundamental, basic form and preferring to put all the theory to one side and hear from those who may have practical experience. I dont think that is too much or too complex or ambiguous to ask

 

All inputs are welcome however as there may be other punters who will benefit from a concise as possible answer

[aertex]

thanks PTG. You obviously get my drift. So it seems you are saying that of the 2 options, channel and clips would have most benefit over mass and damping (>>sheets and GG or alternative)?

 

or another way, structural isolation alone will have more benefit than mass and damping alone? If so, thats easy to process and digest

 

thanks

Alan

Edited February 21, 2019 by aertex

[Guest Peter the Greek]

11 minutes ago, aertex said:

or another way, structural isolation alone will have more benefit than mass and damping alone? If so, thats easy to process and digest

 

Yep - but I'll caveat that, you really want mass as well. Damping is a nice to have

 

There are a number of ways you can achieve structural isolation, I favour clips because they can be retro-fitted, dont take up much space, and are the easiest solution in most cases for ceilings. The room in room alternative can be a real ***** to implement on the ceiling front.

 

[acg]

@aertex, I can give you my experience with my room.  I looked at the STC numbers and every piece of literature I could find and I talked to the guy in Brisbane that is the sole Aus. importer of Greenglue.  My aim was to limit the transmission of sound downstairs to the rest of the house and three of my walls (well two walls and the floor) all adjoin to an open space downstairs, so there is plenty of surface area for sound to push through and cause problems.  My results exceeded my expectations. 

 

Here is the basic gist of what sunk and stayed in my head in regards to soundproofing:

• Seal the room.  Sealant between each and every panel of plasterboard to the ceiling and the floor and in the corners.  Exposed power outlets are best because they only need a hole in the plasterboard large enough to get the wire through and it can be backfilled with sealant.  Good door seals...I have two layers of sealing on my trapdoor.
• Dampen vibration.  Because my entire floor can transmit sound below to the rest of the house I added hundreds of more screws to my floor.  Then I added a second layer of red tongue flooring with Greenglue in between and screwed that down with hundreds more screws and sealed both in-between the flooring panels and between the flooring panels and the house framing.  This really, really works well.  I did not use resilient channel for the walls (screwed the fyrcheck directly to the cypress studs if I remember correctly) or ceiling (normal furring channel).  Two layers of fyrcheck with a Greenglue sandwich for the internal walls, a single layer of fyrcheck for the ceiling because I don't need to soundproof to the outside, soft and fluffy insulation for the wall and roof cavities...I think I used Bradford Soundscreen because it was on special at the time.  The trapdoor is three layers of red tongue flooring with greenglue in between.
• If like me you have windows to the rest of the house then two panes of heavy glass separated as widely as you can manage in the wall space provided (I got about 80mm), with some acoustic foam (I used Basotect Melamine) lining the internal perimeter.  Don't forget to leave some silica inside to soak up any moisture.

 

The Greenglue damped panels act as a bass trap so is pretty good stuff to have in the room if you are going to soundproof...it certainly helps to absorb some of the sound rather than just send it back into the room.  I hope that helps mate...it has worked for me.

Edited February 21, 2019 by acg

[aertex]

Thanks Anthony. Just what I needed. I knew you did much to your room but have been scrolloing through your DIY post looking for the details and couldnt find it it the 2 days I had available

 

My room situation is pretty much identical to yours as in 2nd floor room, living room right below audio room with timber subfloor, 1 side wall adjoining another living area to side and below and 3 other walls exposed to outside/neighbours (although on an acre neighbors aren't super close)  and 2 sliding windows, pitched roof with ceiling currently (to be removed to expose rafters and create volume). I can do any mods needed as this is dedicated room-but dont want to do more than needed for time and $ reasons. I am doing all the work myself, along with the rest of the whole house and garden

 

You not using channel (and isolation) and having great sucess is very interesting for me! I have thought of using a quick cheap alternative to channel as in simply fixing/sticking rubber strip to studs and screwing plasterboard (Fyrcheck/Sund check, whatever) to studs like normal-with GG sandwich between another layer of board. Surely rubber strip will impart some beneficial effect...as opposed to no isolation between board and stud?

 

Also Anthony, is the living room under your audio room now very quiet? Can you explain some sort of descriptive you are experiencing?

 

Alan

Edited February 22, 2019 by aertex

[aertex]

1 hour ago, Peter the Greek said:

Yep - but I'll caveat that, you really want mass as well. Damping is a nice to have

 

There are a number of ways you can achieve structural isolation, I favour clips because they can be retro-fitted, dont take up much space, and are the easiest solution in most cases for ceilings. The room in room alternative can be a real ***** to implement on the ceiling front.

I can handle caveats Peter-no problem. Can I ask you to spell out just a bit more on your clips for ceilings? Are you saying using clips only with no channel? And retro fitting them?

 

How about rubber strips fixed to timber wall or roof frame, under board for isolation? any thoughts or experience there

 

 

Edited February 22, 2019 by aertex

[acg]

29 minutes ago, aertex said:

Thanks Anthony. Just what I needed. I knew you did much to your room but have been scrolloing through your DIY post looking for the details and couldnt find it it the 2 days I had available

 

That thread is getting pretty big...I'm not sure where to look in there myself. 

 

31 minutes ago, aertex said:

My room situation is pretty much identical to yours as in 2nd floor room, living room right below audio room with timber subfloor, 1 side wall adjoining another living area to side and below and 3 other walls exposed to outside/neighbours (although on an acre neighbors aren't super close)  and 2 sliding windows, pitched roof with ceiling currently (to be removed to expose rafters and create volume). I can do any mods needed as this is dedicated room-but dont want to do more than needed for time and $ reasons. I am doing all the work myself, along with the rest of the whole house and garden

 

You not using channel (and isolation) and having great sucess is very interesting for me! I have thought of using a quick cheap alternative to channel as in simply fixing/sticking rubber strip to studs and screwing plasterboard (Fyrcheck/Sund check, whatever) to studs like normal-with GG sandwich between another layer of board. Surely rubber strip will impart some beneficial effect...as opposed to nothing between board and stud?

 

Alan

 

Alan, if you have chipboard flooring then getting it as stiff as possible certainly helps a lot even with things like creaking to footfall noise...I have neither now.  The second layer of flooring installed perpendicular to the original with greenglue in between helped a tremendous amount.  I did not have access to the interfloor space but if I had I would have put some insulation down there as well.  With no close neighbours I would not be at all concerned about soundproofing external walls unless there are areas outside your room that you do no want impacted by sound.  My room leaks noise out the northern windows which then comes in the downstairs windows/doors especially if they are open.  Not much noise gets into downstairs like that, a tiny amount really, but it is the majority of all sound heard downstairs.

 

The most important thing is sealing up the room such that water could not escape through any crack or crevice,  seal everything!  Install the second layer of plasterboard such that it has no coincident edges other than at the perimeter...and fill those gaps with sealant.  Follow the Greenglue directions regarding the density of screws you need to use.

 

One thing that I did not mention in my first post, and I really should have, is that your speakers should be decoupled from the floor, especially the bass speakers.  The cabinets vibrating and directly exciting the floor is a major sound transmission problem and you can end up doing all the other things to soundproof the room and your speakers just start the floor vibrating and a lot of the sound escapes anyway.  Under my Bass Cannons I used pneumatic mounts that isolate from about 7Hz.  Under my upperbass horns I used some much less expensive neoprene mounts that are good from about 20Hz from memory.

 

Rubber strips fixed to the studs was suggested to me, but I did not want to be screwing through it and having it coil up around the screw and putting a bend in the plasterboard, so I decided not to try it.

 

 

 

[aertex]

thanks for all that Anthony-all very appropriate and doable for me. I can insulate inter-floor cavity no problem. There is no insulation there now, just bare formply floor fixed direct to joists and it is noisy as hell

 

Interesting to hear again that you dont have 2 typically recommended design features incorporated in your room (isolation channel and clips and floor insulation) and (along with all the other inclusions) still achieve very favourable results. Exactly what I was hoping to hear in terms of which of the myriad of audio room design options available can be included or excluded and what result will that achieve

 

It tells me clearly that if there are reasons why not all design features can be included, it is not the end of the world as a very good result is not unattainable. No doubt the all in approach is best but that is more time and $$ committed and not every audio punter can committ to that. In the context of a hundreds of thousands of $$ reno of my joint, the audio room must be put into some perspective......sadly I have to say too

 

Alan

[acg]

I still spent about $20k on my room once all the materials were purchased, AC was added, dedicated mains wiring, the windows custom made, carpet, sparky, plasterer, door seals, the trapdoor and linear actuator.  I painted myself and did 90% of the labour myself with a local handyman builder helping to fill in a couple of walls to change an open loft into an enclosed room.  A mate or two was needed to get the fyrcheck panels onto the cathedral ceiling, that was heavy sweaty stuff, and the higher wall panels, but otherwise it is just having a set plan, time and patience.

[Guest Peter the Greek]

2 hours ago, aertex said:

I can handle caveats Peter-no problem. Can I ask you to spell out just a bit more on your clips for ceilings? Are you saying using clips only with no channel? And retro fitting them?

 

How about rubber strips fixed to timber wall or roof frame, under board for isolation? any thoughts or experience there

 

 

Clips and channel go together.

 

Rubber strips don't provide adequate isolation (for bass) - the fixings (screws) just send the sound straight through it. I did some testing on this as we used a product called Shearflex under our frame in our last room. I didn't feel it was all that effective...

 

You really only have two options for isolation, clips and channel or double stud walls (or even staggered studs)

[davewantsmoore]

4 hours ago, aertex said:

I also fully realize the complexities that the physics behind the question presents. But within the complexities, the physics can be stripped back and intentions considered in a most simplistic form to draw a conclusion

We need to know what you are trying to achieve, before it can be "simplified".

 

Do you want to prevent sound getting out of the room (annoying people outside the room)

Do you want to allow the walls to absorb sound?   Do you have a certain frequency in mind?  (A certain problem frequency to solve?)

Do you want to prevent the walls from "rattling"

Etc?

 

In short.

 

Channel decouple the walls from everything else .... meaning the wall can potentially flex more, but the energy from the wall isn't coupled into anything else (eg. the rest of your house).

 

"Green glue" and I assume another layer of plaster....  makes the wall stiffer and more damped, and less likely to let sound pass right through it.

 

Which would you pick?   Neither.    There's no reason to do anything unless you have a specific problem to solve.

[davewantsmoore]

1 hour ago, aertex said:

which of the myriad of audio room design options available can be included or excluded and what result will that achieve

Whether you would include or exclude anything, depends on what you are trying to achieve.

 

Do you care if lots of sound leaks out of your room? .... Depending on this (and other) questions, will push the solution in a certain clear direction.

 

1 hour ago, aertex said:

No doubt the all in approach is best

No.... That is poor logic.

 

Solving problems which don't exist will at best be just a waste of effort ....  but, it could make other areas worse.

[aertex]

I have no desire to argue about this or that. No time or inclination. I didnt post to confuse anybody. If somebody doesnt understand the question posted or otherwise has difficulty processing it........simply dont respond to it. I am happy to hear from those who can understand what I mean and have first hand experience. There are several here who are in this category and I thank you all for providing the information I need. In fact the information I seek has pretty much been answered already. I didnt want a thesis or white paper, just simple guidelines relative to my question-and I have it

 

My posts he are written in sound English and explain all that is needed to be explained-if read. I dont have a 4 walled room at all (the post at the top of this pg2 from me explains what I have). Because I dont have a completed (or actually a 4 walled room/floor/roof space) at all, I dont have the opportunity to "hear" it so I dont have a problem to fix at all at this stage. Pretty basic really. This seems to have been selectively overlooked in some responses

 

The question was asked as if a room was to be designed and built from scratch (which is the freedom of design I have) with the consideration of benefits of 2 elements-GG and isolation channel/clips. I didnt indicate there was a problem to fix....somehow it was assumed. So if that were you what room characteristics would you think might be desirable-considering my descriptive details provided? No need to answer as we both know what they are

 

Thank you all. No real need for further tedious debate and some sort of intellectual arm wrestle. I didnt ever join SNA for that all those years ago. Thats what marriage is for?...dont they say ? (from a 34yr old marriage veteran)

 

all the best to all who took the time to reply. Much appreciated. Over and out

Alan

Edited February 22, 2019 by aertex