If you have some experience playing live then you may already know that the acoustic properties of rooms differ and no two gigs are the same. One deciding factor on the outcome of our guitar sound is the frequency response of the room you’re playing in. Frequency response refers to how different frequencies respond to the reflective qualities of a room.
The physical characteristics of a room cause dips and boosts at specific frequencies, variable to where you are situated inside the room. Controlling room acoustics is a complex task, which is undertaken in professional recording studios. In your local pub, however, you can count on the fact that there is likely to be little to no consideration when it comes to the acoustics of the room.
What to Look out For
It’s rather common to find an unwanted build-up of bass frequencies as well as unwanted room resonance in many performance venues. There are two main causes for this:
- Right angled surfaces, such as wall-to-wall intersections cause prominent frequencies to build up as they reflect sound back in the same direction it’s sent from.
- Parallel surfaces amplify certain frequencies which creates an uneven frequency response.
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In a live scenario, the best we can do to combat frequency build up is change the placement of our instruments. But this is impractical a lot of the time. Many venues are small, and placing instruments in strange locations just won’t fit the aesthetic of our performance. Thankfully there are a few more solutions.
Although placement will mitigate the intensity of reflection, it will not eliminate it. All the surfaces will contribute in some way as a reflective surface for sound waves. Reverberation is the term used to describe this. It’s the quality and length of all delays when sound is produced inside a room. Another term for this would be natural reverb.
Natural reverb can add something special to a performance, but it can also be a performer’s worst nightmare in a bad sounding venue. In an ideal scenario, natural reverb will create a pleasing spatial quality to the sound of our amplifier. If you’re playing in a large hall, you normally wouldn’t have the need for any artificial reverb applied as an effect, as the reverberation inside such a room is so intense.
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Acoustically Treated Venues
Some venues are designed specifically with sound in mind and are treated acoustically. As an example, such a room that everyone has been inside would be your local movie theatre.
In terms of performance venues, a theatre is a prime example. These types of venues are where established bands perform, and are generally inaccessible to the general population.
If the audio track from a live performance is being recorded (for broadcast or a live DVD) you can rest assured that the venue will be acoustically treated in order to ensure a high-quality audio track.
Combating Bad Acoustics
Option #1) Cardioid Microphones
In order to diminish the overall effect caused by sound reflection, microphone manufacturers came up with what’s known as a cardioid microphone. This type of mic only picks up sound directly in front of it, which can diminish the overall room sound to a large degree, but not eliminate it completely. In addition to that, such a microphone has further benefits in the sense that it diminishes feedback. We also don’t necessarily want to detect room sound from a microphone that’s used directly on a guitar cabinet. This means that when you’re not playing, you don’t have to worry about the mic hearing everything on stage. The most common choice for guitar cabinets, which is found in every venue, is the Shure SM57.
Option #2) Corrective Equalization
The largest support element to repair bad room acoustics would be an equalizer. This is post-EQ, which is applied on the mixing desk and is not the same thing as an EQ pedal used on a guitar amplifier.
When corrective EQ is used properly, it’s possible to cut (not boost) problem frequencies. This is the difference between a gig that you’re going to enjoy and one where you’re going to struggle.
It’s no secret that professional bands employ at least 2 sound engineers in order to ensure that they can perform in a comfortable scenario. Not only is front-of-house equalization important, but many bands have opted for a dedicated stage engineer that they can depend on during a performance.
Have Fun with Acoustics
Room acoustics is one of the main factors that make each gig new and exciting. Because different rooms can sound vastly different in comparison, each gig will be a brand new challenge for you to face. You can either have fun with it or feel overwhelmed by it. It’s really up to you.
A final suggestion I would like to make would be to embrace room acoustics musically. If you’re playing in a tiny venue which is surrounded by mirrors (a highly reflective surface) it would make little sense to perform at a very high volume. Adapting your instruments volume as well as your playing dynamics as a musician is the key to getting the most out of the room you’re playing in.
About the Author: Dean Hailstone is a guitarist with 20+ years playing experience. He runs his own blog dedicated to the gigging guitarist found at PlayGuitarLive.com. In addition to that, Dean has performed in countless live and studio sessions alongside some of the countries top musicians.