How to plan for DIY Acoustic Treatment

How to plan for DIY Acoustic Treatment

No matter how good the monitors or the digital to analogue converters that recreate your waveforms are, it is almost certainly the room in which you’re sat that will be letting you down sonically. Many of us, working domestically these days, have smaller than ideal spaces in which to monitor and record. So what can be done, and on a budget?

Common problems
Before we begin, we should consider how a typical room deals with the sound generated within it. That is an important distinction. This series is not about sound proofing, which is an all together different animal. None of the treatments here will help soundproof your room!

Essentially sounds within any room reflect off the surfaces whether that be totally from a shiny hard surface such as a tiled wall (acting as an acoustic mirror if you like) to total absorption (as if there were no surface there). The latter can be experienced in what is known as an anechoic chamber. I’m not sure any of us would like to work in as dead a space as that! However what we need to do is to tame the reflections, or manipulate them to provide us with an even and predictable frequency response.
Standing waves

The first nasty to look for are the standing waves. Those are the waves that reflect and interact with each other either causing a large boost or dip in frequency response at your listening position. These reflections you can often hear in the bass end of your rooms as a boost occurs as certain notes and not others. Already you’re experiencing the unevenness of your listening space.

Make a plan!
The first step, I’d say you need to do, is to draw out a plan view of your room as accurately as you can. Don’t forget to measure the height of the room and note that down separately. Armed with those measurements you need to use a mode calculator such as www.mcsquared.com This will tell you typically where your problem spots are in the frequency range and what you need to tame.

The chances are that the problems will be mostly with the bass frequencies, especially in small rooms where they can reflect sooner without dissipating as the wavelengths are so long. This, regrettably is where the most absorption is required. You could buy a foam product to achieve this or look to the rockwool slab to mop this up for you. We’ll look at how to address bass frequencies in our next post in this series

The next thing to note are the simple reflections to your listening position. Those higher frequency slap backs you hear from the plastered surface of the wall. These really bounce about and blur your perception of what you hear from the monitors, killing your stereo imagery.

In the coming weeks, we’ll look at simple ways in which you can address these in your room with both the common foam products as well as more builder-friendly materials you can grab at your local DIY store.

Written by professional recording engineer and production lecturer Russ Hepworth-Sawyer for the Andertons Music Blog. Check out the original post Acoustic treatment on a shoestring budget on www.andertons.co.uk/blog  for a more in-depth look at analysing your room in preparation for acoustic treatment.

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Ask the Expert – Controlling volume overspill in an old church building – part 1

Controlling volume overspill in church part 2 – identifying the noise-makers

Ask the Expert – how to prevent audio feedback in church