Room Acoustics – Why Your Guitar Sound Changes

Did you know that the room you’re in can have a big impact on the way your guitar as well as other instruments are sounding? This is one of the things that keeps playing live fun and exciting. Every gig is a new challenge, and no two gigs are the same.

So why does the room have such an impact? Why do you have a terrible show in one venue only to have a great show in another? It all comes down to room acoustics and how the reflective surfaces in a room control and color the sound.

The typical room has at least 6 reflective surfaces if you consider the roof and floor. Outside is not immune to reflection either, as the ground equates to at least 1 reflective surface. Acoustics differ depending on the type of surface. For example, in many studios you will find wood being used mainly because of its pleasing acoustic properties. However, in a live situation (particularly restaurants and pubs) we can’t always count on great sounding surfaces.

Your guitar tone will be affected depending on how the reflective surfaces behave in the specific room you’re in. In the ideal situation, the room should be as absorbent as possible in order to mitigate sound reflection and diffusion. This is why playing outside is normally preferred by musicians over indoor gigs, unless of course the venue is treated. Even though there are reflective surfaces outside, they are usually highly absorbent unless you’re playing on a concrete or tiled floor.

Another problem that we’re faced with as a result of sound reflection is the fact that microphones not only pickup direct sound but reflected sound too. In most gigging scenarios your cabinet will be miced and running through a PA system. This isn’t good news for terrible sounding venues, because as guitarists we like to play loud and this means a lot of reflected sound. In order to mitigate this issue, microphone manufacturers came up with what’s known as a cardioid microphone. These microphones only pickup sound directly in front of them – isolating unwanted ambient noise, mitigating feedback and amplification of reflected sound. For guitar cabinets, the most common choice is the Shure SM57. For vocals, it’s the Shure SM58. The main difference between the two is the SM58 is designed to eliminate plosives associated with vocals, while the SM57 is not.

There are, of course, gigging venues designed specifically with room acoustics in mind. Such venues are normally professional concert halls and theaters. In fact, even your local movie theater has been acoustically treated. Because it’s impossible to completely stop a microphone from hearing reflected sound, great acoustics is normally desirable and it can be achieved in these venues. When professional bands shoot a live DVD you can count on the fact that the room acoustics will be taken into consideration in order to record a professional audio track.

If, however, you’re playing in a room with no treatment or a particularly bad sounding room then all is not lost. This where is corrective EQ comes in – or more specifically a skilled sound engineer. As musicians we tend to focus on our instruments and a lot of us lack knowledge in this department. Professional bands normally have more than 1 sound engineer in order to make sure they can perform accurately in a comfortable environment. The fact of the matter is that no matter how good your gear is, you will most definitely run in to acoustic issues when performing live. Corrective EQ is used to address these problems, essentially allowing us to cut out the specific frequencies that are causing the problems. (PS: make sure you’re subscribed so that you can pick up on the EQ tips we will be addressing in future posts.)

A final point worth touching on is the actual performer. The affect of the room will inevitably have some form of impact on the way you’re playing your instrument. The easiest instrument to use as an example here would probably be drums. If you’re playing in a very small venue, with highly reflective surfaces like mirrors (a true nightmare) then playing your instrument at an extremely loud volume will likely have a negative impact on your overall sound. I find that jazz drummers are most prone to adjusting their playing volume to suit the conditions of the venue, and are able to play at a very low volume whilst maintaining power and drive.

Dean Hailstone

Dean Hailstone

Dean is a professional guitar player, recording artist and touring musician. He has over 20 years of playing experience, and has performed hundreds of live gigs during his career. Read more...


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