Room Acoustics and Room Treatment is without doubt the most overlooked aspect of the home audio system. Unfortunately the room is quite frequently the weakest link in a system and to some degree all rooms will introduce distortion, smearing and the ‘muddying’ of the sonic presentation and is guilty of holding back the musical message a system is trying to communicate.
There’s no question that room acoustics and room treatment isn’t as much fun as choosing a new pair of loudspeakers or upgrading to that ‘end game’ amplifier you have lusted after for years, but the reality is whilst these upgrades clearly have their benefits your room will be dramatically holding your system back and preventing you from hearing it (regardless of how good your system actually is) anywhere close to its true potential. People always focus on upgrading their actual system, those larger speakers that move more air and that more powerful amplifier are fundamentally putting more energy into your room and it has to go somewhere!
Essentially when you are listening to music you are listening to your room as much as you are the speakers and the positioning of your speakers plays a huge role, unless you have a dedicated room you may not have a huge amount of choice on speaker placement – room size, existing furniture, door and window locations and of course our wives/partners all play a part in where a pair of loudspeakers can be positioned!
Often the most thought given to room acoustics is a rug on the floor or an appropriately positioned bookcase or armchair. To be fair this may solve one problem, but it will almost always create another issue at a different frequency, unfortunately you aren’t solving the problem you are just moving it elsewhere.
Providing there is some flexibility in speaker position, seat position (more difficult!) and there is space for adding some acoustic treatment of one form or another the performance of any system can be dramatically improved, bigger than any conventional component upgrade and one which will stay with your system through countless upgrades. For those who have dedicated rooms speaker position, seating position and being able to accommodate some room treatment products is generally much easier.
In a typical average sized room only around 20% of what you hear comes directly from the speaker, the other 80% comes from the room, in the form of reflections, rebounding many times around around the room, the percentages will vary from room to room depending on its size. Treating your room essentially involves moving this unfavourable ratio so you increase what you hear directly from the speakers and reduce what you hear as reflections and resonances.
The role of any acoustic treatment is to ensure that the sound emitting from the loudspeaker reaches the listener as unchanged as possible, undergoing as little negative influence from the room as possible.
Resonances & Reflections
The drive units in your loudspeakers move backwards and forwards in a piston like motion which compresses and decompresses air. Our ears perceive this motion as sound when the frequency of the motion is between 20 and 20,000 times a second (hertz essentially).
The speakers drivers are moving air in waves of compression and waves of rarefraction and this is how the acoustic energy is transferred from the speakers into the listening room itself. This energy does not quickly fade or dissipate like it would if it were outside, it hits the room boundaries, is partially absorbed and it bounces around the room, unfortunately it can bounce many times before it is completely absorbed.
These rebounds can have a very detrimental effect on the sound you hear as they conflict with new sounds that are immediately following. How long they last all depends on the dimensions of your room. These bouncing frequencies are often referred to as ‘fundamental resonances’ and can have quite a negative impact on any loudspeaker/hi-fi system.
The lowest frequencies irradiate from a loudspeaker in all directions, whereas the highest frequencies are much more directional. The resultant pattern of radiation from the loudspeaker (from the very lowest frequency to the very highest) goes from wide to narrow depending on the rise of the frequency. As a result only part of the sound coming from a speaker actually reaches the listener’s ear. The remaining frequencies reflect off the wall boundaries reaching the listener with an added time delay. The point on the wall where this reflection arrives absorbs some of it, and then emits it back into the room (at lower energy) and with that time delay.
As amazing as the human brain is it is unable to differentiate separate sounds that arrives within 25 milliseconds of one another. So instead of your brain perceiving sound coming from the speaker directly and sound coming from the wall it perceives just one sound but one which is to some degree distorted and smeared compared to what it should be. Effectively our brains ‘fuse’ together the 2 sounds into one poorer sound.
When reflected sound reaches the ear with a higher delay than 25 milliseconds your ear/brain perceives it to be a different sound, considered separate from the primary signal, it could be perceived as an echo , but you would need to be in a very large space for this to be an issue. In a normal sized room those high energy reflections (that reach the ear within one or two reflections) reach the ear within that 25 milliseconds time frame.
In a typical room containing a pair of loudspeakers, there are 8 primary reflections: 4 on each lateral wall, 2 on the ceiling and 2 on the floor. So each surface generates many secondary sound reflections. All of these sound reflections interact with the dynamics and the tonal balance of the original sound message, deteriorating it both in space and time terms.
The acoustic treatment of a typical living room or dedicated music room serves to replenish the sound with its original features, avoiding the negative influences the room can have on it. In a good listening room, resonances are controlled, they are not concentrated within one single frequency area. Early higher energy reflections are treated so to minimise their negative effects. The acoustic pressure, that has its maximum strength in the corners and close to the walls, is more uniformly distributed throughout the room. The sound energy should be as diffused as possible, so that it is not concentrated in specific points of the room or in specific frequency areas.
The overall acoustics of a well-treated room are controlled yet natural and alive sounding and not overly dampened and dead sounding.
It all comes down to a number of factors
- Speaker positioning and listening position
- What Products?
- Budget & Aesthetic Consideration
- What you like the sound of
Depending on where the speakers are located within a room the air and energy will react in quite different ways and their location will subsequently have a knock on effect for resonances and reflections. The same can be said for the listening position as well. Try moving your seat forward or back by a foot while keeping your speakers in the same position. There are several methods that can be employed to calculate the optimal position for the loudspeakers themselves and the actual listening position which is the ideal starting point for planning acoustic treatment for your room.
As mentioned above, unless you are in a dedicated listening room getting the best position for both the loudspeakers (and especially the listening position) can be a challenge!
By carefully measuring the room dimensions and the loudspeakers position within the room and then attempting to place the speakers in strategic positions based on a number of different formulas (and even using a combination of formulas) will help to optimise the their ideal position. Once the ideal position for the loudspeakers has been established we then precisely map the room and run through it through the computer software and based on the results we can introduce a selection of appropriate room treatment product. Of course, in many rooms the speaker location cannot be changed or adjusted and we just have to work with what we are presented – I like a challenge!
Acustica Applicata and Stillpoints Aperture II Panels are my weapons of choice! They are 2 of the most established and highly regarded room acoustic solutions available in the world today. They are both very flexible in terms of positioning and can be easily moved and adjusted to fine tune how a system (and room) can sound. They are both incredibly effective products and even with a relatively modest investment they have the ability to absolutely transform what your system/room is capable of delivering, they never fail to raise eyebrows!
Why not unlock the full potential of your existing system before throwing money down the rabbit hole!
Founded in 1992 in Tuscany the Acustica Applicata range of acoustic traps were specifically designed to deal with troublesome lower and medium frequencies and they are considered to be one of the finest room acoustic solutions available today.
Their DaaD Towers and Resonators are instantly recognisable and can be seen in many systems from across the world featured in the hi-fi press and are featured extensively on social media, they are hugely powerful in removing the influence of the room from any system. They have powerful computer software that carefully analyses a mapped room and presents you with a number of solutions utilising their products which shows you the behaviour of your room resonances and the frequency ranges where compression and cancellation are located within your room, it allows you to explore tonal balance and articulation within a system and fine tune it carefully and accurately or to an individuals taste based on their musical preferences.
Acustica Applicata DaaD Towers
The Daad towers first launched in the year 2000 although 21 years on we are onto their second generation.
Essentially they have designed a very fast acoustic trap that deals with the resonant frequencies in your listening space without effecting the non-resonant ones. The very lightweight micro-pressed metal sheet with its resistive layer creates friction with the air which is passing through it. Importantly, the DaaD towers does not slow the music transients from following one another.
They are very light, easy to move and adjust, their lobed footprint makes them relatively easy to locate in corners, effectively penetrating the corner area more effectively and therefore capturing the resonant frequencies more efficiently
Unlike a flat panel the DaaD towers can be rotated upon itself so it can be orientated in a particular way depending on the room, the opposing sides of the DaaD offer diffusion and absorption and their position has a large impact on the sound quality. It all depends on the room and the musical tastes/requirements of the customer.
When sound waves hit a DaaD tower they are evenly diffused all of the way around it. The sound becomes more detailed, yet is totally natural and organic in terms in terms of presentation. They don’t fundamentally change the sound of your system, but they dramatically clean it up removing distortion and smearing caused by reflections and resonances.
There are 3 different types of primary Daad Tower plus 2 variants.
The DaaD 4 is the largest tower and deal with frequencies from 50Hz upwards
The DaaD 3 is the medium tower and deals with frequencies from 80Hz upwards
The DaaD 2 is the smallest tower and this deals with frequencies from 120 Hz upwards
The different heights, sizes and shapes of the 3 towers only changes the quantity of the absorbed sound, not the quality.
By strategically locating a number of DaaD towers in key positions around your room (determined by their software) they effectively change the acoustic dimensions of your room dramatically improve the way your system communicates.
The Studio DaaD is essentially a DaaD 2 installed on a small base and telescopic stand, that will raise it height between 23cm and 80cm more than a DaaD 2 – no more or less effective than a DaaD 2 and in certain situations they can be relevant.
The Eco Daad is a more compact version of a DaaD tower, they are a different shape and are optimised to work with frequencies of 260 Hz and above. They are designed to be mounted vertically in the corners of a room or horizontally where the wall and ceiling meet. They are designed to give you a natural sound but one which is very lean and vivid. When the sound waves hit the internals of an Eco Daad the sound heat is converted to low level heat.
Acustica Applicata produce 3 different Helmholtz Resonators which is a device specifically created to deal with acoustic resonance.
They each consist of a volume of air enclosed in a cavity, coupled with the outside space through one or more openings, to create a mechanical mass-spring system with its own resonance frequency, at which the system is able to absorb a considerable part of energy. The absorption of this kind of resonator is very selective about the frequency of resonance and they are particularly effective in the case of excess low-frequency energy.
They do not deal with the same range of frequencies as the DaaD towers.
They can be used in pairs in key locations but are most commonly found directly between a pair of loudspeakers sited right in the middle of the soundstage.
The largest resonator is the Polifemo and is designed for larger rooms (and dedicated rooms most likely as it is fairly tall at 185cm!). The Volcano and Halifax are the 2 smaller models and are much more manageable from a size point of view. Please follow the links to learn more about each of them.
Each of these resonators has been designed to improve the timbre and dimensionality by tuning out conflicting sound waves which distort and smear the musical presentation. They each fundamentally do the same thing, although they are different sizes and as such they are all working at slightly different frequencies to one another, which is correct is largely determined by room size.
They can be used in pairs in key positions in a room, but they are arguably most effective when positioned directly between your loudspeakers, dealing with the turbulence where the energy from both loudspeakers meets in the middle of the soundstage. They also dramatically help to remove the distortion and time delays created by the fact that a significant percentage of the sound you hear doesn’t come directly from your loudspeakers but is bounced off the walls and ceiling in your room causing time delays and distortion.
Stillpoints Aperture II Acoustic Panels
The Aperture II acoustic panels from Stillpoints are quite different to Acustica Applicata and in their own right are very unique, flexible and powerful when employed correctly. They simultaneously act as an absorber, diffuser and resonator all in one.
They are 56.5 cm square and are 8 cm deep, so they can easily be hung on a wall or they can simply be freestanding. I have a customer with a single Aperture panel, day to day it lives behind his sofa and he puts it into position on the floor directly between his speakers when he is going to be using his system. It takes seconds to do and you can hear the impact this has on performance quite easily.
The Stillpoints Aperture is the only acoustical product that will give you both absorption and diffusion at the first reflection points of a system. And you want both!
As mentioned at the start of this post many room treatments often fix one problem but create more issues in other areas, too much absorption can make a room dead and lifeless especially at low volumes.
The Aperture II’s utilise a mixture of ‘absorption‘ material and acoustics chambers to capture excess acoustic energy. The ‘diffusion‘ aspect of the Aperture breaks up the wave forms which will aid mid to high frequency absorption and reduction. The ‘resonator‘ aspect of the Stillpoints Aperture offers control of the lower frequencies. If you have slow, ponderous heavy bass in your room the correction use of Apertures can transform their presentation.
There is no right or wrong way to use an Aperture panel in a room, it depends on the room, the system and how it all sounds essentially.
Behind the speakers, first reflection points, behind the listening chair at tweeter height, directly between the speakers, in the corners of a room…….the list goes on and on with options you have A pair stacked directly between your loudspeakers will give you an incredibly 3D and holographic soundstage, all in proportion with your speakers and room but it will have huge depth and the boundaries of your room will sound like they’ve all expanded and you are listening in a room far larger than you really are.
Essentially it all depends on your room and the sound you are getting, and of course what you’d like to achieve.
- The Stillpoints Aperture are effective from 40 HZ to 40K HZ.
- The Stillpoints Aperture’s unique trapping system captures an area of waveform much broader than its small surface area would suggest.
- The Stillpoints Aperture can be used to trap waveforms either facing the wall or facing away from the wall.
- The Stillpoints Aperture effectively increases soundstage width and depth. This is especially true for smaller rooms. (See the Michael Fremer review: Stereophile, Feb 2016.)
- The Stillpoints Aperture will increase the dimensional perspective of the image structure.
Apertures are available with oak, cherry or walnut frames and with white, black or cream fabric. Standard Aperture wood/insert combinations are Light Oak/Cream, Cherry/Cream, and Black Walnut/Black. The Standard offerings are stocked by Stillpoints.
In many respects Apertures II are easier to accommodate than Acustica Applicata because you can simply mount them on the wall, if you can mount them in the correct places of course. Freestanding Apertures work really well and they are easy enough to put into position when you need them.
Which acoustic treatment is right for me and my room?
There is no right or wrong answer to this question, it really depends on your system, your room and how flexible you are in terms either freestanding or wall-mounting options. Many rooms will be a complete non-starter for Acustica Applicata due to the space it can occupy, especially if your system is in a shared living space, so Aperture panels could be a more sensible solution, but if you have a dedicated listening space you may well have no restriction on what you bring into the room.
How much treatment you need really does depend on the room and what the room mapping brings back. It may suggest more treatment that you were anticipating or budgeting or for, but I’ve had brilliant results from implementing just a selection of the possible options. As always it is a fine balance of performance, budget, aesthetics and what works for you.
Before a room is mapped I always find it worth looking at the room, spending a good bit of time listening to the system and experimenting with speaker position and seating position (usually one or the other is possible to some degree, but not always!). With some time and exploration you can almost always improve the tonal balance and articulation of a system before you have even started with any treatment.
‘Which DaaD towers are right for me?‘ is a popular question – essentially it comes down to the size of your room. There is no sacrifice in the quality of results between a DaaD 2, DaaD 3 and DaaD 4, it’s only the quantity of control that differs.
‘My equipment is directly between my speakers, can I use a Volcano or Halifax?‘ Again it all depends on the room. The image below shows a recent installation, the mapping highlighted the requirement for either a Volcano or Halifax. We managed to bring the Entreq Athena forward just enough so the Halifax could stand in exactly the right position, it was a tight fit, but it had the result we were hoping for.
Popular acoustical problems includes things such as…..
- Confused and ponderous bass weight and resonances due the loudspeakers being too close to the corners of the room
- A harsh, forward sound, caused by backward reflections and the listening chair being hard up against the rear wall
- Too many forward reflections causing a squashed soundstage,
- Sitting too close to the speakers so there is a hole in the middle of the soundstage.
- Too much reverb and resonant energy, which does not have time to dissipate which kills dynamics, especially at low volumes
- An unbalanced image caused by poor speaker up and or bad acoustics (one speaker firing into a window or armchair for example)
- Existing room treatment that has been poorly executed can also have a negative impact on a room/system as well
Any of the above sound familiar? They can all be solved with the correct product implemented in the right way.
If you are interested in listening to some Acustica Applicata or Aperture Panels in your room please get in touch. I can’t stress enough it is not a case of just buying some (or borrowing some) and hoping for the best.
Your room requires mapping and running through the Acustica Applicata Software program in the first instance and we can take it from there. The software will accurately calculate reflection and resonance points and a number of potential solutions based on budget and aesthetics.
The Stillpoints Panels are not of relevance as far as the room mapping goes, but the results of the mapping coupled with our extensive experience will give us some valid suggestions for different locations depending on the results and options.