Start with the room, not the microphone
A spare bedroom can become a very usable voiceover space, but acoustic treatment is not the same as soundproofing. Soundproofing aims to reduce noise travelling in or out of the room. Acoustic treatment controls reflections inside it. For voice recording, both matter: a quiet room is not automatically a good-sounding room, and expensive equipment cannot remove a strong echo after it has been recorded.
Identify the problems before buying treatment
Stand in the room and listen for flutter echo: clap once and listen for a sharp, repeating bounce between parallel walls. Also record 20 seconds of speech from the intended microphone position. Listen for boxiness, brightness, low-frequency rumble and changes in tone when you move around.
Check the main sources of unwanted noise:
- Road traffic, aircraft, neighbours and external doors.
- Boilers, radiators, refrigerators, computers and ventilation systems.
- Footfall and plumbing noise from rooms above or below.
- Reflections from bare walls, windows, floors and ceilings.
Record at different times of day. A room that sounds quiet at midday may be unsuitable during commuting hours or when household heating is running.
Choose the microphone position carefully
Positioning is one of the cheapest and most effective improvements. Avoid placing the microphone exactly halfway between two walls, where room modes can create uneven bass. Do not record directly in a corner unless the corner has been heavily treated; corners concentrate low-frequency energy and can make speech sound boomy.
In a rectangular room, start by placing the performer and microphone on the room’s shorter axis, facing into the longer dimension. Keep some distance from the nearest wall, then make short test recordings while moving the setup by 20–30 centimetres. The best position is the one that produces the most consistent, natural voice—not necessarily the one that looks most convenient.
Use thick broadband absorption
Thin decorative foam mainly absorbs some high frequencies. It does little for the lower midrange that often makes spoken voice sound muddy or boxy. A more reliable solution is porous broadband absorption: mineral wool or fibreglass panels around 100–150 mm thick, installed with an air gap behind them. The gap improves absorption at lower frequencies compared with mounting the same panel directly on the wall.
Prioritise the areas that create the strongest early reflections:
- Side-wall reflection points beside the performer.
- The wall behind the microphone or behind the performer, depending on the recording direction.
- The ceiling above the speaking position.
- The wall opposite the microphone, if it is hard and reflective.
Use breathable fabric and a proper frame, and ensure any mineral-fibre material is fully enclosed. Heavy curtains and a thick rug can help reduce high-frequency reflections, but they should support—not replace—thick wall and ceiling panels.
Control corners without making the room dead
Low frequencies are harder to absorb because their wavelengths are long. If the room sounds boomy, install substantial bass traps in the vertical corners, ideally extending from floor to ceiling. Large, deep traps are more effective than small triangular pieces of foam.
A completely dead room is not always desirable. Excessive absorption can make a performer feel uncomfortable and can produce an unnaturally dry recording. Aim for an even, controlled response rather than simply adding as much material as possible. Leave some absorption-free surface, or use movable panels so the room can be adjusted for speech, music and video calls.
Reduce noise with practical building improvements
Acoustic treatment cannot stop a lorry, boiler or upstairs footsteps from entering a recording. For external noise, begin with simple measures:
- Seal gaps around doors and windows with suitable draught seals.
- Use a solid-core door if the existing door is hollow and lightweight.
- Place the recording position away from windows and shared walls.
- Switch off noisy equipment and schedule recordings around unavoidable household noise.
- Use a dense rug or underlay where footfall and floor reflections are problems.
Do not block required ventilation or create an unsafe, poorly ventilated booth. A small room can become hot and uncomfortable quickly, and performer comfort affects delivery as much as the acoustic environment.
Check the result with repeatable tests
After installing treatment, record the same paragraph from the same microphone position. Compare the untreated and treated recordings at matched volume. Listen for reduced room tone, fewer reflections between words and a more stable voice when the performer moves slightly.
For a more technical assessment, room-measurement software and a calibrated measurement microphone can show frequency-response peaks and decay times. The exact target depends on the room and its use, but the key principle is consistency: speech should remain clear without an obvious ring, boom or abrupt change in tone. Once the room is controlled, microphone choice, distance and performance technique become much easier to manage.
FAQ: spare-room voice recording treatment
Are acoustic foam tiles enough for voiceover?
No. Foam can reduce some high-frequency reflections, but thin tiles rarely control the low-mid frequencies that cause boxiness. Thick broadband panels with an air gap are generally a better foundation.
Should I cover every wall?
No. Full coverage can make a room excessively dead and may not solve low-frequency problems. Treat early-reflection points first, then add corner traps and movable panels according to what you hear.
Is a wardrobe useful as a vocal booth?
A wardrobe full of unevenly arranged clothes can scatter and absorb some reflections, but it is not automatically quiet or acoustically balanced. It can work as a temporary solution if the room is otherwise controlled, provided the performer has enough space and ventilation.
Where should the performer face?
Test both directions. In many rooms, facing along the longer dimension gives reflections more distance to develop, but the best orientation depends on doors, windows, room dimensions and existing treatment.
Can treatment make a room soundproof?
No. Panels absorb reflections inside the room; they do not provide the mass, separation and airtight construction required for meaningful sound isolation. Treat noise at its source wherever possible and record during quieter periods.