Home Recording Series Vol 5 – Recording Environment
When recording, microphones pickup direct sound waves, but they also pickup reflections from the room. These reflections are know as reverberation.
Reverberation creates a rooms ambiance and gives an impression of the size and construction materials. Some rooms have a more desirable tonal quality than others, and a properly designed acoustic space, such as a professional recording studio can have great sounding ambiance worth recording. However, in the case of most home recording studios, this is rare, and once the rooms reverberation is recorded, it cannot be removed. With this in mind, it’s best to record your signal with minimal reflections and add the sense of space during post production. This allows you to have greater control over the desired sound and give the impression of having recorded the source in a different space.
How do you minimise reflections in a home recording studio?
Before we look at the room, it’s worth taking a step back to our microphone placement post. In this article, we briefly touched on the importance of microphone distance, and how less room ambiance is picked up as the mic is moved closer to the sound source. Additionally, the overall signal is stronger and therefore more prominent than unwanted background noise, such as computer fans. The microphone should also not be placed close to a wall, as reflections will be picked up – resulting in degraded overall clarity.
The recording room itself should be controlled. This means avoiding highly reflective surfaces, such as: concrete, tiled floors, and windows. Acoustic foam is the best way to reduce reflections, however this can be expensive and it’s worth trying some cheaper alternatives first. A mattress against the wall, curtains/heavy drapes, book shelves, and hanging a duvet all help to absorb sound and minimise room reflections.
For the purpose of this blog, we will only be touching on the basic ideas, but essentially, it’s best to use your ears. Try moving things around the room and listen for changes in reverberation or tone. Unless you have the luxury of naturally great sounding acoustics, you’ll usually get the best result by making the room acoustically “dead”, and adding the space back in using a reverb plug-in.
Nearfield Absorber – If re-arranging the room isn’t a viable option, you might also consider a portable reflection filter. Primacoustic make a cost effective solution, which attaches to a standard microphone boom stand. Find out more at the primacoustic website.
Keep the room quiet
Higher sensitivity condenser microphones can pickup very quiet signals and the computer is often the biggest culprit of this. Consider investing in a low noise CPU fan and power supply, along with a passively cooled graphics card and decoupled hard drive to minimise noise and vibrations. If the noise is unavoidable, simply move the microphone as far away as possible and use a directional polar pickup pattern to its best effect.
Join us for volume 6, where we look at monitoring for recording and mixing. Subscribe to our RSS feed to be alerted. In the meantime, for more information on home recording products by Shure visit the home recording microphone page.