Room Acoustics: How to Improve Your Recording Environment

Your room is arguably the most important piece of equipment in your recording setup. Even the finest microphone will produce poor results in an acoustically problematic space, while modest equipment can sound surprisingly professional in a well-treated room. Understanding and improving your room acoustics is one of the most impactful investments you can make as a content creator—and it doesn't have to cost a fortune.

Understanding Room Acoustics

When sound leaves your mouth, it doesn't simply travel to your microphone. It bounces off every surface in the room—walls, ceiling, floor, desk, windows—and reaches the microphone from multiple directions with slight time delays. These reflections combine with your direct voice to create the characteristic sound of your space.

Problems arise when:

• Reflections are too strong: Hard, parallel surfaces create noticeable echoes and reverb
• Bass builds up: Low frequencies accumulate in corners and between parallel walls
• Flutter echo occurs: Rapid, distinctive echoes bounce between parallel surfaces
• Comb filtering develops: Reflected sounds cancel or reinforce certain frequencies, colouring your sound

The Two Goals of Acoustic Treatment

Acoustic treatment serves two distinct purposes, and understanding the difference helps you apply solutions correctly:

1. Absorption

Absorptive materials reduce the energy of sound reflections, decreasing reverb and echo. These include acoustic foam, fibreglass panels, rockwool panels, heavy curtains, and soft furnishings. Absorption is the primary solution for voice recording and podcasting.

2. Diffusion

Diffusive surfaces scatter sound energy in multiple directions rather than reflecting it directly back. This reduces strong reflections while maintaining a sense of natural space. Diffusion is more important for music recording where completely dead rooms can sound unnatural. Bookshelves with irregular contents provide natural diffusion.

Treatment Priorities for Voice Recording

For podcasting, voiceover, and spoken content, focus your treatment efforts in this order:

1. First Reflection Points

These are the surfaces where sound bounces directly from your mouth to your microphone. To find them, sit in your recording position and have someone move a mirror along each wall. Where you can see the microphone in the mirror marks a first reflection point that needs treatment.

Typically, you'll find first reflection points:

• On the wall directly behind you
• On the wall you face (behind the microphone)
• On the ceiling above your recording position
• On side walls at roughly ear height

2. Corners (Bass Traps)

Low frequencies accumulate in room corners, creating boomy, muddy sound. Bass traps—thick absorptive panels placed in corners—help control this buildup. Corners where three surfaces meet (wall-wall-ceiling or wall-wall-floor) are priority positions.

3. Parallel Surfaces

Any pair of parallel hard surfaces can create flutter echo. If you can't treat one surface, breaking up the parallel relationship with diffusion or angled treatment helps.

DIY Acoustic Treatment Solutions

Professional acoustic panels are effective but expensive. These DIY alternatives can achieve excellent results at a fraction of the cost:

Rockwool/Fibreglass Panels

The most effective DIY treatment uses rigid insulation batts in simple wooden frames:

1. Build frames from 70mm x 35mm pine (or deeper for more bass absorption)
2. Fill with Bradford Gold insulation batts from Bunnings
3. Wrap with breathable fabric (speaker cloth or even bed sheets)
4. Mount to walls with appropriate fixings for your wall type

Four panels (600mm x 1200mm each) typically costs under $150 in materials and provides significant acoustic improvement.

Heavy Curtains

Thick, pleated curtains absorb mid and high frequencies effectively. Triple-weave or velvet curtains work best. Hang them with air space behind them for improved low-frequency absorption. Position on walls behind your recording position or over windows.

Moving Blankets

Heavy removal blankets (available from Bunnings for $20-40) make effective temporary treatment. Hang them behind your recording position during sessions. They're particularly useful for renters who can't make permanent modifications.

Existing Soft Furnishings

Before buying anything, maximise what you have:

• Bookshelves filled irregularly with books and objects
• Upholstered furniture positioned near your recording area
• Thick rugs on hard floors
• Heavy curtains on windows
• Closets full of clothing that can serve as recording booths

What Doesn't Work

Avoid these common acoustic treatment mistakes:

Egg Cartons

Despite their reputation, egg cartons provide almost no useful acoustic absorption. They're thin, rigid, and the wrong density for sound treatment. They may slightly scatter high frequencies but do nothing for the problematic mid and low frequencies that cause room issues.

Thin Foam

Cheap acoustic foam (especially thin tiles under 50mm) primarily absorbs high frequencies while leaving mid and low frequencies largely untreated. This can actually make your room sound worse—boxy and unnatural with all highs removed but problematic frequencies remaining.

Over-Treatment

A completely dead room can sound unnatural and fatiguing. For voice recording, you want to control reflections while maintaining a sense of natural space. Absorbing too much high frequency energy while bass remains untreated creates particularly unpleasant results.

Treatment for Specific Australian Challenges

Hard Floors

Timber, tile, and polished concrete floors are common in Australian homes and create strong floor reflections. A thick rug (at least 10mm pile) under your recording position provides essential absorption. Larger is better—aim for at least 2m x 3m if possible.

Open Plan Spaces

Modern Australian homes often feature open-plan living areas that are acoustically challenging. Consider creating a dedicated recording corner with portable treatment: a reflection filter behind the microphone, panels or blankets on stands around your position, and strategic furniture placement.

Fibro and Weatherboard Homes

Older Australian fibro and weatherboard homes often have thin walls that transmit exterior noise but may have naturally less reflective surfaces than plasterboard. Focus on controlling external noise with curtains over windows and sealing gaps around doors.

Testing Your Treatment

After applying treatment, evaluate your improvements:

1. Repeat the clap test—the decay should be shorter and less ringy
2. Record test audio and compare to your pre-treatment recordings
3. Listen for reduced room ambience in your recordings
4. Check that your voice sounds natural, not muffled or boxy

Make adjustments based on what you hear. You may find you need more treatment in some areas, or that you've over-treated and need to remove some panels. Acoustic treatment is an iterative process.

Conclusion

Room treatment doesn't require professional installation or massive investment. Start with what you have—soft furnishings, curtains, rugs—and add targeted DIY treatment based on your specific problems. The clap test and careful listening will guide you toward solutions that actually improve your recordings rather than just looking professional.

Remember that acoustic treatment works alongside your microphone choice and technique. A well-treated room with a mid-range microphone will outperform an untreated room with expensive gear every time.

For more on achieving great sound at home, read our guides on reducing background noise and microphone placement techniques.