Do you have problems with bad acoustics in your home? Is it difficult to hear what people are saying whenever you have guests over? Or do you find it hard to concentrate at work due to the sounds in the room being to loud?

Then you are most likely experiencing the consequences of poor acoustics.

Also known as reverb.

And it is not only annoying – it’s isn’t exactly good for your health or well being.

Actually it’s quite the opposite.

If you often find yourself in environments with poor acoustics, then you will most likely experience the following:

• You might get stressed.
• You will find it har to concentrate.
• You might experience headaches quite often.

So as you can see having poor acoustics is bad for your health.

Luckily there’s something you can do about it.

In this blogpost I will walk you through the The 6 things you need to know in order to improve acoustics in a room. 

I was given the chance to interview Thomas Fløcke, who is one of Denmarks leading experts in acoustics. For years he has been helping companies, public institutions and private people with creating healthy sound environments.

In other words – he knows everything about acoustics.

Let’s start with the basics.

1 – WHAT IS REVERBRATION (AKA. REVERB)?

Sound consists of waves – sound waves.

When you are hearing sound, then it is actually sound waves that hits your ears, which is then registrated in your brain as sound. If a sound wave contains a lot of energy – if it is a loud sound – then it will take longer time for the sound waves to die out.

The energy in the sound waves is measured in decibel.

When you turn up the volume you are increasing decibel. And the other way around – when you turn down the volume, you are also decreasing decibel.

All right now.

This is important to know in order for you to understand what reverb actually is.

oh – and by the way – reverberation and reverb are two words for the same thing. I prefer reverb so that’s what I will use from now on in this post.

Let’s start by defining reverberation:

Reverberation occurs when the sound waves continue to reflect in a room after the original sound source has been silenced. 

Reverberation and reverb are two words for the same thing. I prefer reverb so that’s what I will use from now on in this post.

What technically happens when you are experiencing reverberation is, that your will hear the same sound several times – echo, on echo, on echo – which means that thes sound will mix into a big blurry fuzz, which then means that you can’t  hear what is (for an example) being said.

The reason that you hear the same sounds several times is, that you don’t only hear the sound waves that travels directly from my mouth to your ears – you will also hear the sound waves the first reflect on the surfaces (walls, floors or ceilings) in the room, which then hits your ears with a slight delay.

Echo, on echo, on echo.

This is especially a problem if you have lots of hard surfaces in a room.

Now – if we were on standing on a field you would not experience reverb, since the sound you heard would only be the sound that travels directly from my mouth to your ears. The rest of the sound waves would continue on past you not reflecting back to you (since there’s no walls or ceilings to reflect on).

I hope it makes sense.

Now that we have that we have that in place, we can move on to the next thing, which is the things you can do in order to create a good acoustical environment in a room.

2 – HOW TO CREATE A GOOD ACOUSTICAL ENVIRONMENT

Reverb is measured in time and not in decibel (like one would think).

So when you are measuring the reverb in a room, you are measuring how long it it takes for the sound to die out in a room. Not how loud the sound is.

The faster the sound dies out, the less reverb in the room.

As Thomas says:

– When you are working on creating good acoustics in a room it’s all about controlling the reflections in the room so that the sound will be stopped or dampened. 

In other words; we have to shorten the reverberation time.

In general, the way you do so is by mounting sound absorbing materials on the surfaces that the sounds reflects on.

Usually that will be walls and ceilings.

There are several sound absorbing materials that you can use for this purpose, and of course our acoustical panels would be one of them. They have a sound classification of Class A, when you insert mineral wool behind the panels, which means that they are very affective when it comes to dampening sound.

The sound classification – Class A – is the highest available rating that even exists.

It doesn’t get any better.

The way the panels work is that the acoustical felt (which by the way is made from recycled plastic) absorbs the sound waves when they hit the panels. This means that the sound will not reflect back into the room, but will be absorbed in the panel.

This in it self is very affective.

But on top of that, the Akupanel will also dampen sound in another way. The slats (or lamellas) which is fastened to the acoustic felt is also dampening the sound by breaking up the sound waves.

Technically that is what’s called diffusion.

The panels splits up the sound waves when they hit an uneven surface (due to the lamellas) and as a result of that, the sound waves will lose energy, since they are broken into smaller sound waves.

This helps dampening the sound even more.

But as I said earlier it is all about controlling the reflections in the room and you do so by installing a sound dampening material on the surfaces. But where’s the best place to install them panels in order to get the maximum effect out of the panels?

That’s what the next part is all about.

3 – WHERE YOU SHOULD MOUNT YOUR ACOUSTICAL PANELS IN ORDER TO ACHIEVE MAXIMUM SOUND DAMPENING EFFECT?

This is one of the questions that we are being asked times and times again.

And with good reason.

The short answer is that you should place the acoustical panels on the surfaces that the sound will hit quickly. Usually that would be on the ceiling or on and large wall in the room, since this typically will be a surface that the sound will hit fast.

So now you will have to use your imagination.

You have to try – using common sense – to figure out where the sound typically originates in the room, and what surfaces the sound most likely will hit first.

Because it will be on these surfaces that you would place the various sound dampening materials, that will absorb the sound, so that it will be stopped and as a result of that would stop reflecting back into the room.

Most people are able to figure for themselves where the sound originates from and what surfaces the sound hits first.

Let’s take this for an example: 

If you have a problem with reverberation whenever someone is talking in your livingroom, then the sound would most likely originate in the height of the head since this is where the mouth (the sound source) would be.

When the sound originates in the height of the head, then the sound would also hit the walls in the height of the head. And this would then be the most optimal height for the panels to be placed.

And another thing that you would have to consider is that sound is waves, which means that it will spread in all directions. That’s why it is a good idea to distribute the panels evenly in the room.

Again – the ceiling would almost always be a good choice, since it would be a surface that the sound would hit very fast.

So spread out the panels in the room and preferably on several surfaces.

A lot of people has asked whether it’s best to install it on the ceiling or on the walls.

So let’s have a look at that next.

5 – HOW DO I FIGURE OUT MANY PANELS I NEED?

Allow me to just say it like it is:

You will not get a great acoustical environment simply by installing one or two panels in  a room (unless it’s a really small room), if you have really bad problems with poor acoustics.

It would help of course but most likely it wouldn’t be enough.

A good rule of thumb is, that you should cover the equivalent of 25 % of the room’s floor space with a sound-absorbing material in order to get good acoustics in the room.

In order to find out how many panels that is, you can use the following formula:

(Floor space x 0,25) / 1,44 = the amount of acoustical panels that are needed in order to get good acoustics. 

The reason that you have to divide with 1,44 in the end is, that one akupanels covers 1,44 m2 (square meters).

Let’s do a quick scenario:

Let’s say you have a livingroom where the floor space is 30 m2.

So in order to calculate the amount of panels that is need in the room in order to get good acoustics, we use the following calculation:

(30 x 0,25) / 1,44 = 5,2

In this case a total of 5,2 acoustical panels are needed in the livingroom in order to get good a good acoustical environment.

All you need to do now is to round up or down to nearest number, since we only make whole panels.

That wasn’t so difficult, was it?

Ok – now we only have one more thing left to go through.

It’s concerning sound classifications and how to install the panels (with or without mineral wool).

6 – DO I HAVE TO USE MINERAL WOOL BEHIND THE PANELS OR WOULD IT NOT BE NECESSARY?

In general all building materials have a sound classification.

The scale goes from A-F where a Class A represents the best possible rating.

A-B-C-D-E-F

We’ve tested the Akupanels in several tests and in different set ups.

The reason that we have done several different tests is that there are several different ways to mount the acoustical panels. And the sound class of the panels varies depending on how you mount them.

There are two ways to install the panels and the way you mount the panels affects the sound class.

• Mounting the panels directly on the wall without mineral wool makes the panels obtain sound class D.
• Mounting the panels on battens on the wall with mineral wool behind the panels makes the panel obtain sound class A.

(When using battens we recommend a 45 mm. which you drive into the wall first. Then you insert mineral wool (RockWool og Isover) behind the panels, and then lastly – you mount the panels on the battens so that you cover the mineral wool).

Now – I guess you might be thinking:

Why would anyone choose to install the panels directly on the wall if you don’t get a Class A effect?

Well, that’s because the acoustic wall – if you follow our installment guide – will take up 6,7 cm of space from the wall and into the room, which can be too much for some.

That’s why we also tested the sound dampening effects of installing the panels directly on the wall (without mineral wool).

And luckily we found out that it was – Sound Class D.

On a scale of A-F, sound class D is an average class. And that is actually pretty good when it comes to dampening sound.

The primary difference between the set up with mineral wool, and the set up without mineral wool is, that the Class D set up is not as effective when it comes to pitches in low frequencies as the sound class A set up.

That specifically means that the class D setup will not be as effective in terms of absorbing bass and deep male voices.

However – when it comes to pitches at high frequencies – women voices, children voices, glass that breaks and etc. – the two set ups are more or less equally effective.

And the advantage being of course that the Class D set up will only take up 2,2 cm of space from the wall and into the room in stead of the 6,7 cm that the Class A set up will.

So what is the conclusion? What should I choose?

I made my own rule of thumb, that you can use.

All you need to do is answer the following question with a yes or a no.

Do you have very big issues with the acoustics in the room?

If the answer is yes, then you should go for the Class A set up where you install minereal wool behind the panels. Because that would mean that you would be sure to wave goodbye to your acoustical problems.

And the opposite way around:

If the answer is no, then you should go for the Class D set up where you install the panels directly on the wall, since it would take up less space in the room.

It’s as simple as that.

CONCLUSION:

We’ve been through quite a lot – I hope it all makes sense. I think it would be convenient just summarize the key points here:

1. Reverberation is sound waves that reflects on surfaces in a room. In order to improve the acoustics in the room you need to control the reflections of the room.
2. The way you control the reflections in the room is by installing a sound dampening material on the surfaces in the room. It is ideal to use our Akupanels for this purpose since it absorbs the sound and break up the sound waves.
3. In order to improve the acoustics in a room, you should place the acoustical panels on the surfaces that the sound waves quickly hits. This would usually be the wall and the ceiling. Use common sense in order to find out where to place the panels.
4. The sound doesn’t care if you place the panels on the walls or on the ceilings as long as it’s somewhere that the sound hits fast. Place it where it makes sense in terms of your style and the general decor in the room.
5. In order to achieve great acoustics you would need the amount of panels that equals approximately 25 % of the floor space in the room.
6. If acoustics is big problem in the room you should install the panels with mineral wool behind your panels. If you don’t have problems with acoustics then you should install the panels directly on the wall since it would take up less space in the room.

Ok – that’s just about it.

I hope that you have discovered all that you need to know in order to improve the acoustics in your room. Because bad acoustics is not only annoying – it’s also bad for your health and well being.

Don’t let bad acoustics drive you crazy. Fix it 

If you have any questions I would suggest that you watch the video with Thomas in top of this post. And if that doesn’t answer your questions, then you are always more than welcome to contact us.

Thanks for reading this post!

DISCLAIMER: I – Troels Johansson – do not have an education within acoustics. This post is based on research I did and the knowledge I have obtained within my work with acoustical panels. If you have to be sure, you should always consult a professional.

With that being said, I’m fairly convinced that the advice I give in this post is actually pretty accurate