By Steven Swift

"You don’t want to destroy the natural acoustic environment, you just simply need to control the sound ... "

If you’re lucky enough to have a studio big enough for live recording (mic’ed cabinets and/or drums), you’ll quickly find out that sound is a very complicated thing to control. Especially when you have an assortment of materials such as walls, ceilings, furniture, windows and doors.

Every minor detail of the room will alter the sound, hence why all rooms are different and require slightly different treatment to optimize the sound. This is a very complicated subject and can quickly become an overlooked part of your recordings but let’s have a look at some of the more basic elements of acoustic treatment and how this can help.

Treating your recording and monitoring space will benefit you for multiple reasons. If you’re recording or mixing in an untreated room, what you will hear is an unbalanced and coloured response of whatever you’re hearing at that moment in time. The uneven surfaces will create an uneven frequency response (this can be a good thing as well as a bad thing) and instantly colour anything heard in that environment. This is great for certain rooms like Abbey Road Studio and Ocean Ways Studio but living rooms and bedrooms aren’t designed with this in mind so you’ll get the worst case scenario effect.

If you properly treat your environment, you will reduce and remove flutter echo, uneven reflections and frequency response. This will improve everything tenfold as you will hear less colouration in the mix and recording, which will give you a clearer image and soundscape to play with come mixing and mastering.

What we’re trying to achieve is a neutral balance in the room. You don’t want to destroy the natural acoustic environment, you just simply need to control the sound and in certain cases redirect or reduce the reflections.

Absorption and Diffusion are the two types of treatment you need to consider. Products that have absorptive properties such as foam or wool absorb sound and help convert sound into other sources of energy such as heat. This reduces flutter echoes and controls the bright higher frequencies in your sound source.  

Absorption Foam

Bass Traps are another type of absorption but these are designed for absorbing low frequencies. Bass traps are great for stopping low frequency build up in the corners (join between ceiling and wall, floor and wall) of your room and using a combination of soft, hard, thick and thin materials helps to scatter sound more effectively. 

Bass Trap

Diffusion is the scattering of sound through thick, thin, soft and hard material such as wood, plastic and polystyrene. Diffusion is used to help guide and control sound energy.

This helps the mid and upper frequency range of the spectrum along with stereo imaging, Diffusion is used for the sweet spot between your speakers and where you sit relative to the audio spectrum you create. It’s basically surrounding yourself in the best possible sound enclosure.

Applying a small amount of diffusion above your listening area will help to enhance and control the stereo imaging created by the sweet spot setup of your speakers. 

Diffusion Panel

If you want to go the extra mile (due to a large room or loud SPL), you can also isolate your speakers and decouple them from anything which will cause vibration or rattle. This is achieved by using dense pads, which act as a cushion underneath your speaker and subs to reduce the amount of vibration given off from loud playback.

Physical application of any acoustic treatment should be done by a complete professional or, at least, only installed in a temporary fashion with Velcro and not permanently with glue. This is mainly due to the misconception that opposing walls, windows and every square inch of your room needs to be treated.

This is incorrect. Opposing walls, windows and most of your room (by symmetrical design) will be problematic but only 30 to 40 % of your room will need treating if done correctly.

For example opposing walls will cause early and even reflections from both sides. To break this up, you only need to apply one diffusion or absorption method to reduce/scatter the reflection, which will create a better stereo image (as both walls are unbalanced in their reflections).

Opposing Wall

If you do plan to treat your room the DIY way, please read as much as you can from as many sources as possible before committing to anything permanently. Acoustic treatment is a very complex and unique subject for each individual room and space so take the time to get it right or get the right person (company) for the job.

This article only touches on the surface of basic concepts and materials for treating your room. In the future I will return to this subject and go more in depth about how to solve and understand what needs treating and what can be left.   

I hope you enjoyed reading my article and if you have any feedback please don’t hesitate to get in touch!! 

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Steven Swift

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