The Tools We Use to Measure and Treat a Studio Room

Every acoustic job we take on begins the same way: we stand in the empty room with a measurement microphone on a stand and a loudspeaker that can produce a controlled test signal. Walls that look bare do not always sound bare, and rooms that look heavily furnished can still ring. Our ears are useful for deciding what to measure, but they are poor judges of how much treatment a room needs.

The microphone is a small omnidirectional capsule with a flat response, placed where a presenter's head will actually sit. We do not measure from the middle of the floor because nobody speaks from there. Presenter desk, guest chairs and the standing position for a stand-up piece each get their own reading, since a room often behaves differently only a metre apart.

We note the time of day too. Heating, ventilation and traffic outside all change the noise floor, and a studio on a quiet October morning can sound very different from the same room during a busy afternoon.

• Measurement microphone placed at real head height
• Readings taken at every seated and standing position
• Background noise logged separately from room response

The first figure we look for is reverberation time: how long a sound takes to fade away after a clap or a burst of noise has stopped. A tiled corridor can take well over a second to die down. A good speech studio wants a much shorter, even decay so that words land and disappear before the next one arrives.

We take readings across several frequency bands, because a room rarely misbehaves evenly. Hard flat surfaces often leave the upper midrange too lively, which is exactly where consonants live, while the low end can linger because ordinary walls absorb very little of it. A single average number would hide both problems, so we keep the full curve in front of us.

Once we have the curve, we agree a target with the production team. A news desk with fast cross-talk wants a drier room than a relaxed interview set, and the target shapes how much material we propose.

Most of our treatment uses mineral wool and dense foam panels with fabric facings, chosen by thickness for the frequencies they need to catch. Thin foam tiles stuck to a wall are a common first attempt, and they mostly dull the highest frequencies while leaving the muddy lower range untouched. Thicker panels, set slightly off the wall with an air gap behind, reach much lower for the same footprint.

Absorption is not the whole answer. A room stripped of every reflection sounds lifeless and uncomfortable for guests, who need to hear themselves naturally. Where a long bare wall would cause a flutter between parallel surfaces, we sometimes break it up with diffusing panels or simply an irregular shelving unit, so the sound scatters rather than disappears.

Placement follows the measurements. The first reflection points on the side walls and the ceiling above the desk usually come first, then corners where low frequencies gather.

• Dense mineral wool for the lower speech range
• Fabric-faced panels that suit the look of the set
• Diffusion on long parallel walls to avoid a dead sound

Treatment inside a room changes how it sounds, but it does little to stop noise arriving from elsewhere. Part of the survey is a slow walk around the space listening for the things a microphone will pick up and an audience will notice: a humming fridge in the next room, a lighting dimmer buzzing, air handling that rumbles through the ductwork.

Some of these are fixed with simple habits, such as switching a unit off during transmission or moving a fan away from the desk. Others need real work: sealing the gap under a door, adding a second layer to a thin partition, or fitting a soft cover to a noisy extractor. We tell clients plainly which fixes are cheap and which are structural.

We also check the cables and stands. A microphone arm that carries vibration from a desk can ruin a take, and a decoupling mount costs a fraction of a wall treatment.

When the panels are up, we repeat every measurement and compare the curves with the originals. Numbers are reassuring, but the final test is spoken words. We ask a presenter to read a news script at normal pace, then have a guest answer questions from the other side of the desk, and we listen back through headphones in the gallery.

Priya, who leads this part of our work, plays the recording at different volumes and listens specifically for sibilance, boxiness and the faint tail after hard consonants. If anything still sounds off, we adjust a panel or move a microphone rather than add more material for the sake of it.

The handover includes a short written summary of what was fitted, where, and the readings before and after, so the studio's own engineers can maintain the room and spot any change later.

• Spoken-word test with presenter and guest
• Before and after readings kept in the handover notes