Date 21st February 2020 Category Home Theatre   

Improving Room Acoustics

Regardless of the brand or how much you spend on the quality of the AV equipment for your dedicated home cinema or lounge room home theatre – one of the most significant performance limitations of the AV system - is the very room itself.

The reasons for this are actually quite simple.

    1.Your room is constructed using hard materials to create very large flat surfaces.

    2.Those flat surfaces are very effective in reflecting sound around the room for long periods of time - especially in the mid to high frequency range.

    3.The speed of sound is very fast, the size of your room is very small relative to the speed of sound.

Do you find yourself turning up the volume?

When we ask prospective clients what they would criticise most about their current or previous home theatre experiences - be it the simple built in TV speakers or some form of surround sound system – their response often sounds something like this…

“… I struggle to understand what the actors are saying…”

Or most commonly

“…When I’m watching TV or a movie, I have to keep turning up the volume to hear what’s being said, then I have to turn it down again during the action scenes because it gets too loud…”

This is almost always caused by the simple reasons mentioned above and is very often compounded by a number of other factors such as poorly placed speakers and less than optimal seating positions.

The more reflective or reverberant the room is, the longer and more often you will hear the same sounds bounce around the room.

These reflections, which we’ll call “old” sounds, force your brain/ears to be momentarily and repeatedly distracted from clearly hearing and understanding the next wave of incoming “new” sounds – these are the sounds you actually want to hear.
This happens in part because the old sounds are arriving at your ear at the same time and almost as loud as the new sounds; the new sounds are then “competing” to be heard.

When this is happening it’s only natural that you’ll attempt to hear more clearly by turning up the volume of your amplifier - which of course also turns up the volume of the reflections.

How can we fix this?

Well… I suppose you could read a book instead. (ha ha!)

Joking aside; a tailored acoustic treatment solution for the room will vastly improve your experience.

While it’s probably fair to say that any basic acoustic treatment is usually better than none simply because this results in a change that seem like an improvement, your results are maximised through a properly considered design approach.
A proper design will often include consideration for attributes such as seating position, speaker type and placement to mention a few.

Ok…. So how does acoustic treatment work?

Firstly there are three main types of treatments used to control the internal acoustics of a room, these are usually in the form of modular panels which are fitted onto the wall or ceiling surface.

    1.Absorption Panels

    2.Diffusion Panels

    3.Bass Trapping Panels

    Artnovion - Absorption and Diffusion panels

(Note: acoustic treatment changes the behaviour of sound within the room and should not be confused with “sound proofing”. Sound proofing is better stated as “room isolation” which typically requires a very different approach to the construction of the room structure – walls, ceiling and floor – Room Isolation is done in order to control unwanted noise escaping and or entering the room – this subject to be discussed in greater detail in another article).

Absorption Panels
Absorbers are typically made of a material which is porous and soft; such as foams, fabric, and compressed fibres (similar to roof cavity insulation).
The intended action of an absorber panel is to essentially “soak up” sound waves so that almost no sound reflects from the treated area.

Diffusion Panels
Diffusers are usually made of harder materials which are arranged in a way that changes the shape of the flat surface so that it has a dramatically different contour. The action of this type of panel is to scatter reflections; breaking up a sound wave so that smaller parts of the original sound wave are reflected; these are used to shape the sound stage and maintain a sense of energy in the room which would otherwise be lost with too much absorption.

Bass Traps
are employed to rapidly dissipate excessive bass energy; proper bass traps act to capture bass frequencies by converting bass energy (pressure to velocity). The intended result is cleaner, tighter, more powerful sounding bass also serving to minimise bass interfering in the listener’s perception of the overall audio spectrum.

Just about any listening environment will benefit from a combination of the different panel types.

Whether we are designing a room from scratch or creating a solution for an existing system we’ll often start by determining the best place for speakers and seats, or by measuring the locations of existing speakers and seat. From there we are able to determine were the major reflections occur within the room and treat those accordingly with a combination of the diffusers and absorbers.

Vision Living - showroom concept drawing

Ideally, not only should you be able to set and forget your desired volume level, a well-designed acoustic treatment solution should complement the look and feel of the room while at the same time ensuring you experience the sound recording as intended by the producer. Instead of struggling to understand what is going on you’ll be hearing dialogue and other details clearly amongst the explosive effects of your favourite action sequences. The sound stage will seem to extend beyond the bounds of the room making your cinema experience absolutely captivating and immersive.

Please contact us to make an appointment to discuss your home cinema and acoustic treatment needs.

Yale Taylor – Vision Living.