Room Acoustics and Your Sound System

Most audiophile people probably is more focusing on their sound system or the equipments rather than their room acoustics. Actually your room has the most impact on your sound. 

Your speaker system is more like the strings of the violin or cello, while your room is like the body of these music instruments. The speaker is the sound source which is very important for how good they can produce the sound, but it is the room, like the violin or cello body that will form the final sound characteristics for its final effect as what we are listening to. As you might heard that no one can produce the violin as good as Stradivarius almost 300 years ago even with all the new technology and knowledge we have now. It is the magic of how to make the violin body that made Stradivarius violins most famous in the world history.

For stereo sound, we need the room reflection effect to form the illusion of the sound stage. Without room reflections, you will hear two speakers direct sound only that is so called near field sounding. There is many sound effects from your room to alter your speaker sound, but the most important and fundamental one is the room reflection from its sidewall. This is why for stereo sound to form the proper sound stage and sound image, you need to put your stereo speakers in a rectangular shape room.

If you do not have the parallel sidewall or rectangular room, or even you have them but it has the broken sidewall next to your speaker, such as a doorway or big furniture, your sound stage will be compromised or skewed due to the reflection from each of your left speaker and right speaker is different. The delay time difference and amount of the sound reflected from the sidewall to your ear is not what the recording is supposed to be heard as intended. In this case, you will be better off to use multi channel sound system such as SACD with the 5.0 or 5.1 sound that will have more direct sound from each speaker to form the sound stage rather than depending heavily on the reflection of the room sidewalls.

For 5.0 or 5.1 sound system, your center channel speaker will help on your sound image. The surround sound channels will help for the sound stage as they are dominating from the room reflections. Your room will still affect your sound quality but the impact will be much less as your speakers and the multi channel recording from each speaker’s direct sound is much stronger than the reflection sound effects.

If you are serious about stereo sound system, first thing is to find the room at least having 2 parallel walls that you can put your 2 speakers in between and next to them. The front wall is also quite important but not as critical as the two sidewalls. Front wall will affect your bass more. The back wall is the least critical one out of the 4 of them. Back wall is mainly affecting the reverberated sound which bounced back behind your listening position. Obviously to achieve the perfect sound you will need to get all 4 walls in the right dimension ratio based on the acoustics theory, well, ceiling and floor are important too.

Your speaker to its sidewall distance and the speaker angle facing to your listening position is the next most important thing you shall worry about, as the sound wave phases are affected by your room . This is related to your room size and your speaker design. The guidance from online such as Cardas room setup guide will be your good starting point. Then you will need to use the stereo speaker setup test tone to fine tune your speaker placement to achieve the optimized sound for your room and your speaker as each case is different. Your room height, surface material, and the surrounding furnitures will be the major reason why you need the test tone to fine tune your speaker placement in your room. You can find more detail on my other discussions about this. This will help you to get the best sound for your current sound system setup in your room, especially if you do not have a dedicated listening room.

Audyssey room correction is very common for home theater now and it can be also very good to calibrate the multi channel sound system for music due to the reason I mentioned above. It can adjust the sound delay and the frequency response from each channel for your listening position. But room correction is much more difficult for the two channel stereo sound system as the room reflection effect is much more complex than just the sound delay and frequency response impacts. Room correction technology is still evolving and it is getting better with the digital signal processing (DSP) capability we have now. But this approach has its pros and cons especially if you do not like digital alternation of your sound. 

Room treatment is a very big topic and not everyone is willing to do so especially you do not have a dedicated listening room. But to achieve that ultimate sound, this will be your next step for your audiophile journey.

Don’t get me wrong, I am not saying your speakers and audio equipments are not important. They are as that violin strings material and how to mount it is very critical for better sound too. They all have their own signatures and performance impact, but this shall be considered after you have understood your room impact and learned how to optimize your sound with your current system setup in your room. When you start to chase those nuances, you are transitioning yourselves from a music enthusiast to a true audiophile ;-)