Soundproofing with Mass Loaded Vinyl versus Plasterboard

Here's an honest manufacturer - if you read their Mass Loaded Vinyl test data, you will see that it does the same as a similar mass of plasterboard. Of course plasterboard is cheaper and takes probably 1/10th of the time to install. Interestingly the say "Pay attention to the word INSTALL. Correct installation is critical to this product working the way it is designed to work." And if you have ever hung, taped and tried to seal MLV you will appreciate how almost impossible it is. Still, great to see honest raw data out there -

Read the article and test data here


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Free Acoustic Advice - Will you come to my place and spend an hour showing me how to cook?

I just got off the phone from yet another restaurant with noise problems. It's almost a daily occurrence.

Every single one says "can you come out and give us some advice on how to fix it?". When I tell them that I am happy to, but I will charge them there is usually a silence followed by something like "but I just want advice". I then explain that no one can just look at a room and/or listen to it and know what is needed. (sadly this has been created by acoustic products sales people who will say whatever it takes to get a sale and walk away with no responsibility for the outcome).

My point is though, if I were a bit quicker, that I should have said sure, I'll come and give you advice for free. Will you come to my place and spend an hour showing me how to cook?

This isn't limited to restaurants. Many places say they just want advice, thinking acoustics is something we have magic powers for and can just appear and tell them what to do AND get it right. Well we don't. What we do have is qualifications and experience and paying for our time is highly valuable in that it gives some assurance that spending money on fixing acoustic issues will be cost effective and actually work.

If you want free advice, just ask the acoustic foam sales guy. Oh and when you want cooking lessons, ask the tomato sauce sales guy....

Forums Vs. Test Data for Soundproofing

Here's an example of a facebook thread that shows how hard it is do discern what is reliable versus what is old wives tale on line. I'm not suggesting that you don't DIY, I love it myself. I am suggesting that it's worth, and in fact there is very good value in, engaging an acoustic engineer. I think I have removed names etc...

What if I'd said I want to build a sound proof band rehearsal room? Would that shift people into a different mindset?

 Yes. That could be done considerably cheaper. But your shed and slab and power will still eat up your $20K. Maybe you could then do the build for another $20K?

 I spent $30k converting part of my house into a studio, and it was far from a no expense spared operation. I can however, recommend a layer of rubber sheeting in the build. I did it in the drum room, but not the control room, and the difference in isolation is very noticeable. I used Acoustiblock, but I think any heavy rubber sheeting will do the job. Also there is a guy in the sunshine coast who turns shipping containers into studios for about $30k

 Have a look at some of the " Tiny Kit Homes " on google... https://www.google.com.au/#q=tiny++kit+homes

Would digging a subteranian space be a viable alternative to sound proofing? As in, dig a room sized hole in the gound, like you would for a pool, and build a below ground studio?

Another option is to bury the "shed" by piling soil around and on top of it like a bunker.

Rammed earth walls?

Andrew, have you checked out the John Sayers website for studio construction? it really does have all the answers to your questions. my thread is dog & bear under 'other studios'. it's a two room build, one control, one live. you can play drums in it at night and we live in a quiet country town......but I'm not kidding mate, it would have been $150k for contractors to build. (it's a much, much different process to building a house) finding the right contractors who will spend 4 X the amount of time to do what normally takes them 1 X to get the right end result is expensive.

btw, I did use green glue in my build and it works as advertised if applied correctly.

John Sayers did a great job for all three of our builds some of the best sounding spaces

I was confused looking at the John Sayers page. It looks like a forum, is it/he a business as well?

Yes it's a forum. Or you can hire him to design your room.

Yes to green glue

Sound absorbition insulation made by earth wool from Bunnings and I think a granny flat would sound better than a shed

Call me if you want

Just following on from this discussion. Looking at possibly buying a place that already has a shed the size of a three car garage with power.


I were to sell the tin shed that's already there, what would you suggest I build on the slab that remains?

 Bessablock filled with sand

Easier said than done and then there's the roof.

Why not a concrete slab ceiling? Lots of town houses have them, can't be that difficult.

Concrete 's not going to stop the sound.

Concrete is great. Just need a small cavity and plasterboard

seriously? If concrete's not a sound barrier then what is?

Test labs that we use have 600mm concrete walls ceiling and floor and are NOT that soundproof. Solids transmit sound bettet than air. A properly built cavity wall works well.

So what do you suggest? A single layer of brick with a cavity then plasterboard with green glue?

Andrew Steele are you sure that the 600mm room doesn't have leaks or weak spots somewhere?

Would be awesome

Yes it gets tested before it is used to determine the TL limit for sample testing

But everything I've read says concrete is a great sound insulator

 I've been reading for 30 years and still learning. If you don't believe me call csiro victoria

And great at stc or rw? Thatd not what you are dealing with

 Sand filled things is a good example. It may be good and it may not. Concrete filled may be better worse and may be cheaper or dearer. The point is that without lab test data you are GAMBLING. You could waste hard earned money on an anecdote. Especially if you don't exactly replicate how it was done in the anecdote. Good engineering gets the most performance from the simplest components.

 So, you're suggesting that I literally call the CSIRO in Victoria and ask them for tips on building my shed studio?

No they could only tell you how to test it. Engage a professional. You will find most if what you need athttp://www.ultrafonic.com.au/Dyn.../id/3/acoustic-advice.htm
But you can't expect to work out how to do something on the Internet that takes professionals years to comprehend. Read the stuff at the link, formulate a plan and run it by me if you like

www.ultrafonic.com.au
07 3103 0591

The value of acoustic engineering

Here's why acoustic engineering is good value, in other words the outcome is worth more than the cost of the service. This school was told by an acoustic foam supplier to cover the ceiling. I did the calculations for the classroom and came up with 1/3 of that amount. The calculations cost a LOT LESS than 2/3 more acoustic panels. Not only would have they wasted all that money but it would have been too dead. As it stands they are very happy and had this comment from two students;

"Yes we have installed the panels in our two science classrooms, and the sound dampening effect is excellent. The difference is immediately apparent to everyone who walks into the rooms now. My students took a few days to adjust to the new acoustics with one year 9 students upon being in the new room for about 15 mins said she was feeling dizzy because something just wasn't feeling normal and the room felt strange, another student then exclaimed, no its just that the room is now "normal" and with no echo now."

Correct acoustic treatment in a classroom from reverberation time calculations

Also, I did the design to the Australian Standard AS/NZS 2107. This means that if they weren't happy with the result they could check it against the standard, and if I had advised them wrongly, seek rectification. If the acoustic foam sales person gives advice that is wrong, there is no recourse as it has no way of being checked.

Adding absorption is not a linear process. Once the correct amount has been calculated, adding more doesn't give as much benefit.

Product information - click here

or call us

Ultrafonic Pty Ltd

07 3103 0591
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Notes on Green Glue application

Notes on Green Glue application.

These are based on years of application and tens of thousands of square metres applied in some of the highest performing soundproofing applications in the world.

The simple but very important rules;

• Use between two materials of similar bending properties e.g. 2 sheets of plasterboard. MDF, ply,

• Apply in a random pattern to the specified coverage (almost always 1 tube for each 1.5 square metres,

• Troweling neatly will not improve the performance, so random application, like sauce on a burger, is fine, and much quicker,

• Do not use in combination with other glues,

• Screw or nail the sheets together exactly the same as you would normally if there was no Green Glue,

• It is an adhesive but not used as such because it takes 30 days to cure, so fix things ignoring Green Glue as an adhesive,

• Clean off well before it dries with soap and water,

• No, it doesn't come in other colours.

More information is available at www.ultrafonic.com.au

Construction drawings, pland and published articles on soundproofing are also available at http://www.ultrafonic.com.au/Dynamic/id/3/acoustic-advice.htm

Otherwise, please call or email if you have questions regarding soundproofing or room acoustics.

Ultrafonic Pty Ltd

07 3103 0591
www.ultrafonic.com.au
Ultrafonic on Google Maps

   

Low Frequency Wall Isolation for Studios and Home Theatres – Or why the Building Code and Plasterboard Manufacturers Get it Wrong.

The reason that this is even a topic for discussion is the nature of the spectrum of sound in music and movies. There is a LOT of low frequency energy in both. Much more than what is in sound that common building methods are designed for. Building codes and systems are driven by sources like speech, traffic and light activity like cooking and washing, and of course cost. These sources have very little low frequency content and hence the rules and systems built around them fail significantly at low frequency – and hence why we always hear the “doof doof” of music, movies and games through such walls. In fact, the standard practices can make the wall WEAKER at low frequency.

A cavity wall (a stud with plasterboard each side and some insulation inside) has a resonant frequency just like a drum. At resonance the wall has minimum soundproofing and will pass the most sound – this area is where the graphs dip around 50 to 100 Hz. Above this, from say 160Hz, the walls are dominated by the mass in them and adding more plasterboard provides more soundproofing. (note that each extra layer adds less benefit each time). At resonance however, adding mass just changes the resonance, a bit like a thicker guitar string is as loud as a thin one but the have a different resonance so one has a lower pitch than the other. In the case of the wall trying to soundproof against music or movies, where the sound energy is highest at around 50Hz, you can see that adding layers of plasterboard adds no extra soundproofing and actually moves the resonance to a lower frequency where the problem is worse (louder sound in the source).

The second graph is another way of looking at this and shows how much sound gets through the wall. Where the “doof doof” is, the wall with more plasterboard is actually WORSE.

So the message is not only that adding more plasterboard may make matters worse for soundproofing studios or home theatres, but that adding layers more than two decreases in value rapidly as well. The second layer doubled the cost of plasterboard for an extra 10dB, the third layer tripled the cost but only added 7dB and the 4^th layer only added 6dB.

The solution to the low frequency isolation of cavity walls dilemma is to use constrained layer damping (CLD). CLD is designed to damp the resonance and increase the soundproofing at low frequency. For more details of CLD systems click here. or contact us at www.ultrafonc.com.au