52 replies to this topic

[atty]

Well here’s the situation, i just bought my first system but hardly get the time to actually play it at reasonable levels. I’m seeking some advice on sound proofing and room layout. My room is a converted attic constructed primarily of jib rock, with insulation bats on the roof and as far as i am aware of there is no insulation on the sides, but ill will confirm this tonight. As to being a uni student with limited funds, DIY is my only option. Im still to source rockwool, the semi rigid fiberglass insulation. Anyone know where i can source sheets of this in NSW?
This is the front on the room. Not sure how i can implement bass traps in the corners due to the inclining roof.

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would there be a problem with covering all the vertical parallel walls with rockwool?
Here is the back of the room, with stairs coming up to it. I’m currently building a wall that will have a door hung of it. There are 3 bedrooms that are 5 meters in front of this view on the first floor, so preventing sound going in that direction is my number one priority. Advice on doing this is greatly appreciated.

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a closerlook... sorry for the mess.

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There is a layer of acoustic foam under the carpet, im still unsure of how much bass travels through the floor but this will be confirmed once the door is put up. Im planning on getting new carpet, but what if i just lay it on top of the one already there?
So any recommendations would be most appreciated. Thanks

[Peter the Greek]

Bass traps / panels etc are for room acoustics.

Soundproofing is very different. Have a read of the articles at www.soundproofingcompany.com

In summary, there is no cheap way to fix this for you unfortunately.

[atty]

I can confirm the walls are double skinned with insulation. i read this, interesting. Though how can this green glue be so effective? Wouldn't sheets of rigid rock wool be more effective at a converting sound into heat energy?



sorry, copy paste didnt do what i wanted...

Edited by atty, 30 April 2012 - 07:43 PM.

[LogicprObe]

The more carpet you put down the better.............but what are you trying to achieve?

(looks like a nice space though)

[atty]

cheers. Being able to play movies and listen to music at around 50 to 60 db at night. I understand its very hard and virtually impossible to block out sound... I have jimmy Barnes living next door and even with all his money i can still hear the banging of his drums.

[atty]

i understand bass is the hardest to assorb, and if that means me not playing bass music at night i will do so.

[LogicprObe]

Yeah, well.........what I meant was, are you trying to stop sound going down into your house or out into the ether?

[atty]

Down into the house.

[LogicprObe]

Down into the house.

What?
You don't care about upsetting Barnsey?

edit - You need to at least put this inside that wall you are building.

http://www.bradfordi...s-internal.aspx

I've used it, it works well at reducing sound through walls and floors.

Edited by LogicprObe, 30 April 2012 - 08:13 PM.

[atty]

hahah not at all, the other night he had a Elvis theme party, it kept me up all night!!!

[atty]

ahh yeh i saw the sound screen at bunnings, When applying it, should it be double packed or left as a single layer?

[atty]

i like the sound of this.... pun intended

• A SoundScreen insulated wall will give an improvement of 6Rw (approximately 6dB) over a non-insulated wall. This equates to a 75% reduction in sound power level.

[Peter the Greek]

Doesn't really apply to bass - you need to read about flanking

[LogicprObe]

Yeah.......but it goes inside the wall.
You'll only get one thickness in side that wall you're building, if that.
You can't have it in the open...........it's itchy crap!

[atty]

yeh i wouldnt have in the open. To get a R value of 41 it needs to be in a 90mm cavity.. I only made the cavity 50mm, looks like i just made more work for myself!

[LogicprObe]

I've used it in 50mm.
Takes a bit of squashing of it with the lining but it still works OK.

[GregWormald]

Until you get the sound proofing adequate to your needs, I'd let the tuning of the sound go.

While double carpet on the floor might not be the best from the carpet angle, it will certainly block out more sound. (Does anyone know if felt or rubber under the carpet is best for minimising sound leakage?) Whether the bass will travel *through* the structure of the house you will soon discover. If it does, there is little you can do without major alterations.


With the half height walls on the sides and the sloping roof, the sound should be pretty good. The irregular far end wall will help as well.

I hope it all works out for you. Keep us informed about how it goes.

Greg

[atty]

ill post some photos later on in the week of the progress.

[LogicprObe]

Using two doors with an airspace in between makes a hell of a difference too.
They must make an airtight seal when closed though.

I'd see how that goes first.
If there is still a problem after that, you'd have to look at isolating the floor by using a carpeted floating floor on top of the existing carpet.

[atty]

While double carpet on the floor might not be the best from the carpet angle, it will certainly block out more sound. (Does anyone know if felt or rubber under the carpet is best for minimising sound leakage?) Whether the bass will travel *through* the structure of the house you will soon discover. If it does, there is little you can do without major alterations.

underneath the current carpet there's a layer of rubber/foam. I could lay another layer of this on top of the current one aswell. That way having a total of two layers of foam and two layers of carpet.

With the half height walls on the sides and the sloping roof, the sound should be pretty good. The irregular far end wall will help as well.

I would have never of thought that area would have aided the room acoustically.

[LogicprObe]

It's all about not having parallel walls if possible..........thus reducing standings waves.
Weird shapes are good in acoustics.

[atty]

Using two doors with an airspace in between makes a hell of a difference too.
They must make an airtight seal when closed though.

Yeh ill be doing a a double ply door with a 40mm cavity, 50mm just seams way to big. Making it air tight is going to be a bit of a challenge but perhaps not impossible. If you look at the photos of the back of the room you may be able to tell that the door will have to be a bi fold, But luckily my father owns a steel door and window company, hopefully he has a trick up his sleeve.

[Vitruvian]

Whilst all of this is going on also look into REW Room eq: http://www.hometheat...ack.com/roomeq/ (it is free) and a calibrated mike.

Sound proofing is considerate, but taming a space provides the sonic backdrop for your equipment to do its thing. It is probably the biggest single tweak you can make to have your music shine. Bass traps, such as those you referred to in your first post are always a good idea. As Greg said above, once you have adequately sealed the space look at treatment.

While you are waiting to complete this here is some information to begin to consider - it will help you work out where you want to go once you are ready:

http://www.ethanwine.../acoustics.html

http://www.infinitys...inf-rooms_3.pdf

Edited by Vitruvian, 01 May 2012 - 09:28 AM.

[mr-happy-pants]

To summarise at a very simplistic level.
My understanding is that the 2 most effective ways to stop sound getting out is:

*Less air gaps
*More mass

Air gaps are your enemy. Door seals and tubes of acrylic sealer are you friend.
Eleminate air gaps around doors, window frames, architraves, plaster joins etc from the path you want to restrict the sound going eg down the stairs.
maybe more sound will travel through an air gap than you realise.

The more mass in a surface, the more sound energy is required to get past it.
Solid doors work better than hollow doors
Thicker glass works better than thinner glass
More carpet works better than less....

You get the idea.

Closing air gaps is a cheap & effective option. Maybe start there.

Graham

[atty]

Whilst all of this is going on also look into REW Room eq: http://www.hometheat...ack.com/roomeq/ (it is free) and a calibrated mike. Sound proofing is considerate, but taming a space provides the sonic backdrop for your equipment to do its thing. It is probably the biggest single tweak you can make to have your music shine.

down loading now, looks like very nice program!

[atty]

Saw this in a youtube video.. Its just an idea, there will be offcourse many flaws in this design.. but it has one very valid pro, its cheap!

here is a drawing, i understand im less prone to standing waves if the wall is less rigid, but how far can you go before it starts to act as a drum? The space between the wall and the added jibrock will be loaded with a form of acoustic insuation.

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[Norman Varney]

Noise control is about blocking, absorbing, breaking and/or isolating sound energy. It is usually acomplished via systems which incorporate combinations of these methods. Means of noise control can be applied at the source, along the path ways, and/or at the reciever. At the source would mean turning the volume down, and/or turning off the low frequencies. At the receiver end, it might mean ear plugs.

In your scenario, you are trying to mitigate the sound along the many paths (flanking). As mentioned by someone else, the long low frequency waves will be the most difficult to deal with, and structure-born vibrations will likely be priority one (over air-born sound transmission) for them.

I would suggest keeping speakers, especially subs, away from room boundaries (good for sound quality as well), as well as decoupling the speakers from the floor via spikes, etc. A floating floor is a great idea and not as expensive as you might think. Owens Corning makes a foam matt, then plywood, carpet pad and carpet. This will probably be the most bang for the buck regarding attenuation of low frequency vibrations to the rest of the residence, though floating the walls would also be benificial. Once low frequencies get into the structure of the building, they are connected to all rooms and easily travel to the furthest end.

I'd then look at solid, sealed doors at both the top and bottom of the stairs to block the primary air-born sound transmission. Pad and carpet on the stairs may also be helpful for any still escaping higher frequencies.

Also, any connected HVAC duct work is an acoustical intercom and will need to be lined with absorbing duct board at both ends.

If you want to dive a little deeper into noise control, read our article at http://www.avroomser...atres_Alter.pdf

I've also attached my drawing depicting flanking.

Attached Files

•  Flanking drawing.jpg   53.71K   37 downloads

[atty]

thank you. The idea of a floating floor seams very piratical, something i could do myself! Any recommendation on what material to use for floor spikes? I could guess cast iron as its bloody stiff.

[atty]

If you want to dive a little deeper into noise control, read our article at http://www.avroomser...atres_Alter.pdf

Very informative article, thank you for sharing. Certainly one i will be referring back too.

[atty]

well i made a LITTLE bit of progress over the weekend. photos speak a million words

Insulation has changed a lot since i last saw it, looks like a good quality product.

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As you can see i have no more horizontal struts, learned from the article Norman Varney shared that less wood is better.

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I used this black 5mm foam to hinder the transfer of vibrations from the particle board to the wood supports. The chuck was set to low on the battery drill to prevent the foam from being crushed. You may be able to see that i have 4 be 2's backed to back, reason being so i could fit the Bradley sound shield in without squashing it or having to cut it down.

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The out side, painstaking job fitting this stuff.

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In hindsight i would have not used particle board but opted for several layers of jibrock. Used the 4 be 2's on edge, that way less wood more insulation.

The good news is i have noticed a slight decrease in sound reaching down stairs... i can prove this because its 10pm and im still playing music and nobody has told me to turn it down.


So onto part two, the door.... Im thinking of four layers of 5mm plywood with green glue and rock wool in between with a solid hardwood frame to keep everything intact, what do you think?

[Vitruvian]

Just remember that the horizontal members (nogging) in stud wall are for lateral rigidity, so make sure that you don't remove all of them!

Over than that concern, it looks good.

[atty]

I have already removed them, 12mm sheets of particle board and 10mm of pine cladding make it rock solid. But i agree with you, if it was a structural wall i would have left them.

[atty]

nothing to update as yet... but i have been on the quest for sound isolation products and there methods of use

Here are the process's i intent to do in order to sound proof my room

Floor
- remove insulation under floor and replace with bradford 90mm thick sound screen
- place recycled rubber pads over joist and lay pre-existing particleboard.
- lay 10mm thick MDF ontop of the particle board with green glue inbetween, facsten mdf to particleboard.
- lay tung and groved bamboo flooring with 3mm cork underlay.

Walls
-place bradford sound screen behind gyprock and staple chicken wire to joist to secure it.
- place another layer of high density gyp\rock against pre existing gyprock with green glue inbetween.
- replace electrical switches for surface mounted.

i Dont have the time and money to decouple the ceiling from the rafters, so is it still worth doing it to the walls?
Bradford claims that with a standard 90mm wood stud with 10mm of standard gyprock on both sides achieves a Rw value of 44 db, so by adding two layers of gyprock and green glue significantly increase the Rw value?

[berun12]

i Dont have the time and money to decouple the ceiling from the rafters, so is it still worth doing it to the walls?
Bradford claims that with a standard 90mm wood stud with 10mm of standard gyprock on both sides achieves a Rw value of 44 db, so by adding two layers of gyprock and green glue significantly increase the Rw value?

I believe so.

I have one small wall done with typical 10mm gyproc, shakes like hell are resonates when thumbed.

I have other wall with two layers of firerated gyproc 13mm & 16mm with genrous layer of Green Glue in between. Solid as concrete (almost

I would use two layers and Green Glue if possible. In fact I would not hesita to put extra, thrid layer with some extra Green Glue, more mass and dampening are your friends.

thanks, bedope

Edited by berun12, 09 August 2012 - 02:38 PM.

[atty]

How mnay tubes of green glue did

I believe so.

I have one small wall done with typical 10mm gyproc, shakes like hell are resonates when thumbed.

I have other wall with two layers of firerated gyproc 13mm & 16mm with genrous layer of Green Glue in between. Solid as concrete (almost

I would use two layers and Green Glue if possible. In fact I would not hesita to put extra, thrid layer with some extra Green Glue, more mass and dampening are your friends.

thanks, bedope

how many tubes of green glue did you use per a 2400 by 1200mm sheet of gyperock? Did you notice a decrease in sound out side of the room?
cheers

[berun12]

How mnay tubes of green glue did


how many tubes of green glue did you use per a 2400 by 1200mm sheet of gyperock? Did you notice a decrease in sound out side of the room?
cheers

3 tubes per one sheet. If you want to add the third gyprock layer, probably extra 1 maybe 2 tubes per sheet max should do.

Yes, I did notice difference in sound pollution both ways. My neighbour cannot hear my trumpet anymore Its much better, maybe not to a level to watch "Godzilla" with realistic should level, but that was not my intention anyway. Also I use, along Green Glue, their resilient channel with their clips. That layer was addition to existing brick wall.

None less, there is significant difference in stiffens and dampening between 10mm gyprock vs 13mm+GG+16mm.

berun

Edited by berun12, 09 August 2012 - 03:38 PM.

[atty]

it will be an interesting exercise to see just how much green glue and high density gyprock can absorb... Where did you purchase the green glue from?

[berun12]

it will be an interesting exercise to see just how much green glue and high density gyprock can absorb... Where did you purchase the green glue from?

Green Glue company advice 3 tubes for the best results. I would say that probably right considering initial coverage before sheets are pressed against each other. Also they say tubes to get 75% performance of 3 tubes (or something in this line). % are deceptive, I would prefer to see dB.

Personally if you have space and money I would advice this:

existing wall + studs and insulation + resilient channel channel + clips + 16mm fire rated gyproc + 2/3 tubes of GG + 13mm fire rated gyproc + 1/2 tubes of GG + 10mm of fire rated gyproc.

And dont forget about sealant around. Gyproc should not touch the existing structure in any point.

And dont forget about flanking paths as well

I got GG from Brisbane supplier http://www.ultrafonic.com.au.

berun

Edited by berun12, 09 August 2012 - 04:18 PM.

[atty]

thanks for that berun, ill give them a call.

[LogicprObe]

Yes, but the biggest source of transmission will still be the floor.

[atty]

Yes, but the biggest source of transmission will still be the floor.

i plan on decoupling the floor of the joist by using 6mm rubber pads. The rubber i plan on using is reconstituted car tires, though im starting to think it may be too hard/un-elastic to hinder the flanking path. Do you have any cost effective ideas up your sleeve?

[Peter the Greek]

doesn't sound like it'll work - give Embelton a call, they'd have something

[MWR]

Try looking at this

http://www.efig.eu.c...ts-reduce-noise

[LogicprObe]

i plan on decoupling the floor of the joist by using 6mm rubber pads. The rubber i plan on using is reconstituted car tires, though im starting to think it may be too hard/un-elastic to hinder the flanking path. Do you have any cost effective ideas up your sleeve?

If this was available in Australia, it might save pulling the floor up.

http://www.allaboutu... 6m2_UL0091.htm

[atty]

If this was available in Australia, it might save pulling the floor up.

http://www.allaboutu... 6m2_UL0091.htm

cheers that looks great.. With a density of 2500kg/m³ fi bet it works great!