Soundproofing and Acoustics

Is Noise Pollution the Next Big Public-Health Crisis?

noreply@blogger.com (Ultrafonic) — Tue, 24 Sep 2019 23:52:00 +0000

https://www.newyorker.com/magazine/2019/05/13/is-noise-pollution-the-next-big-public-health-crisis

Applying Green Glue Noiseproofing Compound

noreply@blogger.com (Ultrafonic) — Thu, 19 Sep 2019 22:14:00 +0000

noreply@blogger.com (Ultrafonic) — Fri, 23 Jun 2017 01:27:00 +0000

Noise management for venues

Usually, a noise limit is set, and if you go above it, penalties apply.

It is set at a fixed position in the venue and calibrated to a lower noise level at the receiving point (usually neighbour). For example, if anything over 105 dB LA_eq inside the venue causes excessive noise at a neighbouring receiver, the limit will be set at 105. It is usually measured at 3m from the PA system.

This is very common and suffers a multitude of problems...

Limiters are installed in the venue to prevent going over the noise limit. They either, turn the power to the PA system off when the limit is exceeded, or compress the music when the limit is exceeded.

The power cut off system does give some warning but once it cuts off there is silence until it resets. There is a great story about a wedding for a very wealthy couple where the band was nicely under the limit, until someone started dancing wildly and the guests all started cheering and screaming. The limiter turned the sound off at that point and the rest is obvious....
All sorts of illegal bypass methods are tried including covering the microphone and dangerous bypass wiring

The compression style limiter does not turn the sound off but tries to turn it down as the music gets louder, and in doing so destroys the sound of the music.
The most common problem with this type of limiter is DJs and sound engineers who either don't understand how they work or don't know they are installed. As they try to increase the sound level in the venue the limiter is “fighting” their efforts. They then try harder to increase the sound level so the limiter compresses the sound even more, until they give up in disgust and blame the PA system for sounding bad.

When a neighbour complains about noise from a venue it can be checked at the neighbour's property. The level is usually set at a small amount above background noise. Background noise is measured over a long period of time to average out spurious noises like vehicles passing. However, if there is more than one noise source at the time of complaint, things get difficult. For example, an area with bars and restaurants will have all of them contributing to the noise on a Friday or Saturday night. If a neighbour complains, it is really impossible to determine which one is responsible. Even if one is a little louder than normal, but still under it's own limit, the sum of all sources may be above the limit at the neighbour's property.
When setting noise limits, regulators use the sound energy equivalent to that of a constant sound pressure level for a set period of time – NOT the sound pressure level at any instant. This is to help the measurement align to the human hearing system and what it finds objectionable. The limit may be specified in units of La_eqdB or L₁₀dB_.Venues using cheap sound level meters are not only relying on inaccurate equipment but they are measuring the wrong thing. Sound Pressure level (SPL) is not La_eqdB or L₁₀dB, and the heated arguments starting with “but we had our sound level meter on all night and never went over the limit” are futile. It's a bit like having a 60km/h speed limit and saying “but I only went 30 metres”.

So what is the ideal situation?

No power being switched off or compressed.
Being able to prove that the venue complied with the La_eqdB or L₁₀dB limit using a high quality system that securely logs all measurements for proof.
Showing that the limit was not exceeded inside the venue and therefore complaints must be from other or cumulative noise.
Ideally, a system that calculates the current La_eqdB and looks at the trend to give a “prediction” of if and when a limit may be exceeded in the future (remember, the limit is total energy equivalent to a constant level for a period of time, so it can be calculated on the fly). This allows a manager, DJ or engineer to simply turn it down a little.

The solution - the system of choice is called 10EaZy. It is a unique and intelligent design that succeeds because it considers the viewpoint of the regulator, venue, sound engineer/DJ and patron. 10EazY is even legislated for all venues in some countries.

Interestingly, feedback has shown that not only are limits managed better but sound engineers have have focussed more on creating a good mix than just turning it up!

For more information, acoustic advice or pricing, please contact us at;

info@ultrafonic.com.au

07 3103 0591

or go to the 10EaZy products page here.

www.ultrafonic.com.au

Common mistakes in DIY acoustics

noreply@blogger.com (Ultrafonic) — Thu, 20 Apr 2017 22:02:00 +0000

Just goes to show that acoustics ain't that simple, when even someone like DPA gets it wrong. This is littered with errors caused by trying to precis a complex topic.

By example, angling walls to avoid room modes is wrong. In fact it skews them and makes them harder to figure out. It doesn't make them any less.

But UNBELIEVABLY, they are quoting NC figures for background noise!!! This is derived from the human hearing response but microphones don't have ear canals..... So a decent NC figure can still have plenty of low frequency noise and guess what a sensitive mic does with that!!!

http://www.dpamicrophones.com/mic-university/10-important-facts-about-acoustics-for-microphone

NC Curve

Church almost destroyed acoustically

noreply@blogger.com (Ultrafonic) — Wed, 11 Jan 2017 03:36:00 +0000

I just did a design for a church as a paid consulting engagement. It is roughly 50 x 25 x 5m.

There is already carpet, upholstered seats, curtains etc. However there are some concrete, some SIP and some plasterboard walls. Obvious flutter echoes can be heard between them.

The calculations show, with about one third occupancy, a reverberation time (RT60) of 1.6 seconds. For a room volume of about 6500m^3 this fine and agrees with AS/NZS. Rudimentary measurements confirm the calculation.

AS/NZS 2107:2000 recommends reverberation times of;
1.0 seconds for Spaces for speech
1.3 seconds for Cabaret and Theatre restaurants,
1.7 seconds for Music Studios;
for rooms of approximately 6500 cubic metres

With the room full it approaches 1 second, which is a little too low. Worship spaces are used for purposes that commonly require all of the above functions, so a compromise is always needed. Generally, a high RT60 increases the engagement of the congregation. More problematically, a low RT60 isolates people and they miss the community experience of the congregation. So the objective is to maintain a suitable RT60 and eliminate problematic echoes that may interfere with speech intelligibility or clarity.

They had originally asked suppliers of acoustic absorption to quote on what they needed. Of course this is like asking the Ford dealer what car is best - an obvious conflict of interest! A large polyester supplier quoted them almost 200 sheets of a mixture of 50 and 25mm thick polyester. This would have destroyed the acoustics of the room in terms of a worship space. But they would have sold over $30k in polyester! Not only that but the calculations on this amount show that after a certain point, adding more absorption makes very little difference i.e. the room is "killed off" with a small amount of absorption and the rest is just wasted.

I have advised them to add NO absorption and construct some simple diffusers to reduce the flutter echoes. This will maintain energy in the room for an inclusive community experience and reduce problematic echoes. If for some strange reason the result demands a lower RT60 some absorption could easily be placed on the ceiling - but I very much doubt it will be needed.

Including my fees, and constructing the diffusers, they have probably saved over $25k and avoided a complete disaster.

So the message is, get qualified advice and don't ask someone selling a product how much you need....

Contact us on 07 3103 0591 or enquiries@ultrafonic.com.au

How to soundproof a wall that has no insulation in the cavity

noreply@blogger.com (Ultrafonic) — Tue, 10 Jan 2017 04:38:00 +0000

Adding layers of plasterboard to a wall to increase the soundproofing may not yield great improvements if there is no insulation in the cavity.

It is reasonably easy to knock holes in the wall between the studs and above and below the noggins. Then you slide some insulation up and down into the slots just created.

Simple pink batts are sufficient. In this case we used some scraps of 32kg glasswool that were lying around to get rid of them. If you can, spread the insulation around in the cavity as it will perform slightly better than if it's all stuck in one corner. You can use a stick to push it around.

Then you simply put rough patches in the holes and plaster over them.

A bit of plaster cement and a quick sand and it's ready for a layer of plasterboard and Green Glue

noreply@blogger.com (Ultrafonic) — Thu, 08 Dec 2016 23:42:00 +0000

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

Contact us on 07 3103 0591 or enquiries@ultrafonic.com.au

noreply@blogger.com (Ultrafonic) — Thu, 18 Aug 2016 00:11:00 +0000

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

noreply@blogger.com (Ultrafonic) — Mon, 20 Jun 2016 00:22:00 +0000

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

noreply@blogger.com (Ultrafonic) — Wed, 25 May 2016 04:52:00 +0000

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
www.ultrafonic.com.au
Ultrafonic on Google Maps

Notes on Green Glue application

noreply@blogger.com (Ultrafonic) — Mon, 23 May 2016 03:46:00 +0000

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.

noreply@blogger.com (Ultrafonic) — Fri, 25 Mar 2016 02:22:00 +0000

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

noreply@blogger.com (Ultrafonic) — Wed, 08 Jul 2015 23:46:00 +0000

Soundproof a room

Sound travels through air and it travels through the solid building materials that make up the structure of your room; i.e. the floor, ceiling and walls.

So first step, you need an air tight room.

Problem, you need air to breathe. So you need a ventilation system to get air into and out of the room, whilst at the same time reducing the sound transmitted through that ventilation system. For some ideas, we suggest you look at Ventilation Silencer - October 2010

Next problem, you need to be able to get in and out of the room, so you need to make the door air tight. We suggest you look at Double Door Noise Lock - October 2010

You’ll also need to ensure that all joins, wall-to-wall, ceiling-to-wall, and wall-to-ceiling are airtight using a product like Green Glue Noiseproofing Sealant

Next step, you need to reduce the sound transmitted through the structure of your room; especially applicable to low frequency sound.

Adding mass helps. Note, however that to reduce sound transmitted by about 10dB, you have to quadruple the number of plasterboard layers on your wall. That’s 4 layers on plasterboard on the inside of the stud and 4 layers on the outside; and, similar for the ceiling and floor.

Damping significantly reduces how much the wall, ceiling and floor resonates; the vibrations you feel when you put your hand on a surface near a loud sound source. You can significantly reduce the sound transmitted through the wall with damping; this is where Green Glue Noiseproofing Compound comes in. We suggest you watch the slide presentation to see how it works

Decoupling is valuable. Using double or staggered stud walls will reduce the sound transmitted through the studs. Green Glue Noiseproofing Clips will reduce the sound transmitted from the plasterboard to the stud. Decoupling also improves the effect of added mass, especially at low frequencies.

Finally, absorption gives just a little more performance. You should add some fibreglass or polyester insulation to the cavity behind your walls, ceiling and floors as it helps to reduce the sound transmitted via air from the internal surface to the external surface. But note, it does very little on it’s own.

An article with more detail is here or call us on 07 3103 0591

noreply@blogger.com (Ultrafonic) — Wed, 08 Jul 2015 23:05:00 +0000

Practical Acoustics – facts, not marketing, by Ultrafonic.

We get asked over and over about how to design soundproof walls. The reason varies from recording studios to noisy neighbours. Sadly, there are a lot of myths surrounding soundproofing, most of which are aimed at making manufacturers more money rather than giving customers more soundproofing.

Lets start with “sound” insulation batts. There's no such thing. They are batts. Choose any of the manufacturer's technical manuals and find the acoustics section. They will all show similar data because it is simple physics that has been lab tested and calculated to death.

An empty cavity is bad. However, much more than a simple wall insulation batt only yields a very small increase in soundproofing (typically 1dB) but the cost is much higher. For example, in the table below, a 10mm plasterboard cavity wall on a 70mm stud gets Rw 39 with a Gold Batt but only 1dB more with a Soundscreen Batt.

Have a look at the price difference below that! And these are just examples from public websites selling insulation. There is no real difference between manufacturers. If anyone has other data and prices to contribute, please do. We'll work on adding more over time.

So instead of spending lots of money on very little gain in performance, perhaps we could find other soundproofing materials or techniques that give us more “bang for buck”?

Look at the last graph to see what a huge difference sealing gaps makes. Sealant is cheap and quick to apply. Making the wall airtight by sealing all of the edges and penetrations is likely to give much bigger soundproofing increases than cavity insulation other than a simple batt.

To see how to seal the wall properly, click here

Out of interest, you can also compare how little extra soundproofing you get on bigger studs. In this case you spend more on wider studs and lose floor space.

R2.0 Insulation Batts 430mm - wall & floor pack 22

cover per pack 9.0m2

- $5.85 per square metre for Rw39

$52.69

R2.0 Soundscreen Batts 1160x430mm 8 batt pack

Each pack covers approx 4.43m2 when installed
- $11.40 per square metre for Rw40

$50.52

Nearly double the price to go from Rw39 to Rw40

Effect of sealing on level of soundproofing

The band in church is too loud.

noreply@blogger.com (Ultrafonic) — Tue, 02 Jun 2015 02:00:00 +0000

If you have problems with the band in church being too loud,

07 3103 0591
enquiries@ultrafonic.com.au
www.ultrafonic.com.au

Quite often a space that is acoustically suited to congregational singing isn't suited to a gospel rock band.

Sometimes, a lot of money is spent on making it right for the band and the congregational singing no longer works.

The acoustics can be made to work for both but it's a complex design needing quite a bit of experience.

For some more detail click here

Most commonly, the band has a drummer and a bass rig on a small stage which is close to the front seats. There is NO WAY this can work. Even if the PA is turned off, it will be too loud in the front seats and probably everywhere. Again, there are great ways around this but they take skill and experience e.g. setting up in ear monitoring, electronic drums etc.

Basically, the technology has been adopted way too quickly, probably because PA systems are big and glamorous. The groundwork hasn't been done to make sure the space can work acoustically in different modes and the band can play without blasting people out of their seats. So slow down, get good, qualified advice, spend some time and money on the less glamorous components, and everyone can be happy.

Office Acoustics

noreply@blogger.com (Ultrafonic) — Tue, 14 Jun 2011 01:48:00 +0000

Open Plan Office Acoustics

Open plan offices with workstations having screens that don’t go all the way to the ceiling are common place. They make good use of floor space and create a pleasant atmosphere due to their open and light nature.

Those same open plan offices also suffer from a lack of privacy and a high noise levels. Their layout and composition generally means that people can hear other people's conversations and realise that other people can hear theirs.

Much work has been done towards developing an open office style that promotes teamwork but preserves privacy and keeps noise levels to a minimum. It has shown that in general, the factors that influence speech privacy fall into two groups:

Those that have a large effect on speech privacy and should be optimised.

Absorption of the ceiling
Screen height
Workstation plan size

Those that have less effect but should still conform to a minimum value.

Panel absorption
Panel Transmission Loss
Floor absorption
Ceiling height
Ceiling mounted lighting

Most problems with office acoustics occur after the office is occupied. People and phones get busy and the speech level goes up as everyone tries to be heard over the noise.

Only some of the parameters that affect privacy can be altered after construction. Of those, ceiling absorption is the most likely candidate for an improvement (if it hasn't already been taken care of). It has a high influence on privacy and can be retrofitted easily. Screen height may also be raised with the addition of panels to the top of the screen (may be transparent).

For offices with a speech privacy or noise problem, Ultrafonic provides acoustic treatments for the construction of new offices and the retrofit of existing offices.

www.ultrafonic.com.au

check this video about Basotect out

noreply@blogger.com (Ultrafonic) — Thu, 26 May 2011 05:07:00 +0000

http://www.youtube.com/watch?v=6JwR9bHd8oE

Basotect acoustic foam

noreply@blogger.com (Ultrafonic) — Fri, 20 May 2011 06:33:00 +0000

Basotect is a light weight, open cell melamine resin foam made by BASF. It's unique properties, including resistance to fire, resistance to chemical and microbial attack and stability over a wide range of temperatures, make it ideal for sound absorption in a wide range of environments. Ultrafonic uses Basotect to manufacture a range of acoustic products and can supply Basotect sheet for acoustic applications.

The high value of symmetry in a control room

noreply@blogger.com (Ultrafonic) — Thu, 19 May 2011 04:21:00 +0000

I have done this so many times now it really needs to be posted.

Brad at Empire studios asked me to come over and have a listen to his new control room. http://www.estudios.com.au/ He has done a great job on the build and is now setting up the desk, monitors etc. The imaging wasn't as good as it could be though, so we spent half an hour with the tape measure laying things out just like they should be. The results were great and now the stereo image is fine. When the acoustic treatment is finished this will be a great studio. (see this article) I can't stress enough how important symmetry is in a control room.

Home Theatre or Surround Sound

noreply@blogger.com (Ultrafonic) — Tue, 15 Jan 2008 23:27:00 +0000

Here goes another post that could be misconstrued as complaining, but it's not. My point is to help set reasonable expectations for those spending time and money on this very popular entertainment. One reason for even thinking of doing this is the number of calls we get from people who have gone down the home theatre path, only to have all sorts of problems with the sound. It is always harder and more expensive to rectify after the fact and often impossible to make the system live up to the original expectation. My job isn't being a psychologist trying to reset peoples expectations and make them happy but that's what I end up doing. In effect I am cleaning up after sales people who mislead, either consciously or not, to get a sale. A bit of honesty and education on their part would go a long way to making happier customers who will more likely be return customers. Not to mention the simple human decency of being honest.

The first thing to remember is how the sound for home theatre is made. It is done in an acoustically treated room with speakers set up like this.

They are full range speakers and the sub is not used as such. All the bass comes from the 5 identical speakers. The sub is called LFE and is only used to add extra emphasis to Low Frequency Effects.

Every departure from this setup is a departure from how it is meant to sound. Of course very few people can have such a dedicated setup and so compromises are reasonable to expect. The average home theatre is so far from this setup though, that it has slim chance of creating the intended sound. In fact it becomes more "surround sound" than home theatre - hence the title of this post. In other words there will be plenty of sound everywhere and some level of effects. It won't however be the intended experience. This of course is fine and most people will be happy with it. It is certainly an improvement over just a TV.

It's not only the quality of overall sound effects that we get calls about though. Common complaints are that the bass is uneven around the room and boomy in places, dialogue and loud effects are so vastly different in level that constant volume adjustments are made, and listening at anything above moderate levels becomes tiring quickly. These kinds of problems are not experienced in a correctly setup and acoustically treated room.

Acoustics for Hi Fi and Home Theatre

noreply@blogger.com (Ultrafonic) — Mon, 07 Jan 2008 23:40:00 +0000

In the modern home there seems to be a minimalist design trend at the moment. It uses tiles and wood floors, long flat rectangular walls and ceilings and lots of glass. Quite the opposite of some years ago where everything was upholstered, carpeted and curtained. They also have a lot of open plan design with lounge, family room, dining room and kitchen often running into each other.
These type of rooms have no chance at all of being good for listening to stereo or home theatre. They are an acoustic nightmare and it doesnt matter what equipment you use, it will not reproduce the program as intended by the recording engineer/artist. To get some idea of why, consider the environment it was engineered in and what a good listening room is like. First and foremost, since we have 2 ears, one each side of our head, the room MUST be symmetrical. It can't have reflections or reverberation that is sufficient to interfere with the sound from the speakers and it cant have direct reflections in the immediate area - like hard walls and ceiling. The size of most listening rooms is similar to the length of bass frequencies which means physical effects like standing waves will occur. Some form of control commonly known as bass traps must be used as this effect can not be corrected electronically.

Ultimately, if you are striving for a genuine reproduction of what was recorded you need a dedicated room!
So what's the point of this rant? It doesn't mean that unless you have a dedicated room you shouldn't have a HiFi or a home theatre, but you should set your expectations properly and perhaps not spend money on relatively very expensive marginal improvements like some of the crazy cables available. It means that if you have a room that is not ideal, don't go crazy on acoustic treatment either. Just get whatever soft furnishings, rugs etc that you can in there. Perhaps use some acoustic treatment that can also be decorative like the Fonic Acoustics Designer Panels. Don't spend time, money and effort trying to make such a room sound perfect because you won't be able to. Don't pay people to advise, measure or sell you anything other than the basics. Have the right expectation that it will sound OK or possibly even good but not sensational or anything like the real thing.

I write this because I get so many calls from people who have bought very expensive gear and put in a beautiful modern home and it doesn't sound good at all. They ask me to consult and fix it which as I said is almost impossible. My point is that this would be a lot more acceptable if their expectation was reasonable at the outset. HiFi and home theatre sales people should be able to make this clear to their customers at the time of sale. They may not get quite such a big sale but will have customers who aren't dissapointed when they get home and are much more likely to be return customers.
Some more information can be found in the articles here - http://www.ultrafonic.com.au/Articles.htm

Practical Soundproofing and Acoustics

noreply@blogger.com (Ultrafonic) — Sun, 23 Dec 2007 23:58:00 +0000

I have created this blog in an attempt to cut through some of the confusing information out there regarding soundproofing and acoustics. Most of it simply frustrates and saddens me because it causes people to spend time and money on things that should generally bring joy but more commonly bring disappointment.

I'm going to be as blunt and provocative as I can and do it quite openly. It's not an attempt to annoy anyone but rather to draw out what is real and what is not. More so it is meant to get to what is appropriate and cost effective. My analogy is that anyone can build a bridge over the river that is perfectly safe and will never wear out with a very smooth ride - just fill the river with millions of tons of concrete and put huge pipes under it! This however is far from good engineering, which to me is getting the best possible result within a budget and making it appropriate for the owner/user/customer.

I'll make a start soon but if anyone has specific ideas or questions, I'll do my best to answer them.
In the meantime you may find some useful stuff at www.ultrafonic.com.au or www.fonic.com