Sunday, November 9, 2008

Acoustic Treatment

Acoustic Treatment is crucial for all types of rooms that has sound system installed. Without proper acoustic treatment, you are listening to the "room" rather than listening to the sound system. Sound waves travel in all direction and if not treated correct, can create echoes, reverberation, resonance and reflection. No matter how good your sound system is, you are actually listening to the room more than listening to your expensive sound system.

I am not going to talk about soundproofing here. Meaning to say isolate sound from your next door neighbour or building a sound tight room. What I will be explaining in this post is to simply explain the basic acoustic treatment you can do to improve your Home Theater Room.

To make things simple, I will just briefly talk about 3 types of acoustic panels that will help you with your home theater room. The three types are Sound Diffuser, Sound Absorber and Bass Trapper.

auralex diffuser.gif

Diffusor does not absorbs the audio waves but diffuses the waves and spread it out into different directions in your home theater room. It prevents audio waves from travelling/reflecting to the listener directly which creates hot spots or nulls in the room. It widens the sweet-spot in your room, thus making the room sounds wider than it physically is which in term give you more 3D sense of openness. DIY product can be egg trays which is really cheap but doesn't look really nice in a well designed home theater room.

Application: First reflective point for the front speakrs. Side walls, Ceiling, behind speakers or behind audience.


Absober simply absorb audio waves and it is non reflective like diffusor. It is effective in alleviating slap and flutter echo. Effective use of absorber can turn a huge room into a suitable acoustic environment. The two most commonly-used sound absorption materials are high-quality acoustic foam and specialized acoustic fiberglass. Not the stuff you can easily get from IKEA or your local hardware shops. I've tried using local hardware shops material like high density rock wool and DIY the panels myself. But the cost per piece is almost the same as those professional panels made by Auralex. Plus, the weight of the DIY panel is so much heavier and you can't really get the equal standard of each panels. Plus mounting the DIY panel onto the wall needs drilling whereas Auralex product comes with a special glue where you can simply apply a single dot on each corner and it will stick on all surface strongly.

Application: Behind Audience, Side or behind Speakers depending on the room layout.

bass trap.jpg

Bass trap acts almost like acoustic absorber that functions to capture low frequency audio waves. Low frequency audio waves are very long and strong which is also the hardest to control. You can either block its transmission or absorb it to clean up the low frequency within a room. Improper treatment of low frequency will affect the sounding from the bass driver of the speaker or subwoofer. Bass traps provide a means to control room reverberations at low frequencies, a part of the audible bandwidth especially troublesome when critical listening venues are located in small rooms. Controlling low frequency audio waves is harder than controlling mid or high frequency waves. With Auralex bass trap, you can be rest assured to get the right solution because of the material used in Auralex bass traps.

Application: Corners

Conclusion, to properly treat your home theater room, you first need to know what is the problem of the room. It is unncessary to stick the panels all over the room because you still need the sound waves to roam freely but in a controlled manner that can help them sound better at your sitting area.

Check out the sample products at Sound Fusion Sdn. Bhd. and get the information you need for your acoustic treatment. We can also recommend the cheaper way of using DIY products :)