Measurement in control rooms

We measure new emerging and already existing recording studios throughout Europe, evaluate their acoustic quality and make suggestions for improvement.

There is quite a number of measurement methods and listening tests to evaluate the quality of a control room. But what actually defines a good control room?

An ideal control room is basically neutral and does not modify the audio material through its own room acoustics. It reproduces the timbre unadulterated and transmits all audible and tangible frequencies equally.

The perfect control room does not boom and also reproduces sub basses crisply, but massively. It only sounds sharp or peaky, dull or hollow, if the played audio material already holds these characteristics.

The ideal control room is free from early reflections and shows an Initial Time Delay Gap (ITDG) which complies with the ITDG of big concert halls. It is neither too reverberant nor acoustically “dead”, but shows a pleasantly natural, neutral spatial representation of the audio material.

The perfect control room does not change its sound according to the playback level and works with every professional loudspeaker. It reproduces slightest differences between different microphones, preamps, compressors, EQs, converters and cables.

The ideal control room shows hundred percent of stereo symmetry and a sharp phantom center, which means, it reproduces mono signals exactly between the loudspeakers and not just ‘somewhere over there’.

The perfect control room does achieve all of that not only at the listening position but everywhere in the room. And, last but not least, an ideal control room does not tire you and always offers joy in listening – even after a 12 hours mixing day.

Bauer Studios: Johannes Wohlleben during the listening test

Geometry of a control room measurement

As sure as there is not the ideal partner or the perfect guitar, there is no perfect control room in this world. But making serious mixing decisions is much easier the better the requirements mentioned above are fulfilled.

In already existing control rooms measurements of the frequency response for an objective analysis are a common method besides listening tests. In this way it is possible to test which frequency ranges have a weaker or stronger weighting during the playback in a room and therefore are being tonally distorted. Especially in the connection of subwoofers the phase position towards the main loudspeakers which is determined by the measurement of the phase response plays a key role. From the impulse response, it is possible to measure the early reflections and to determine the ITDG. The reverberation time gives information on the reverberation of a room, although, in our opinion, it is often overestimated as a real design criterion for control rooms. On the other hand, measurements of the swing-out behaviour (waterfall display) are essential to determine the low frequency decay. The low frequency range shows the position of the dominant eigenmodes and is an important indicator for the design of the bass absorbers.
>> Modal analysis

Measurement report control room

Listening session

These measurements document the status quo before the start of the room acoustical optimization as well as the success of the treatments and allow an objective and comparable evaluation. They are no substitute for detailed listening tests, but their necessary addition.

From time to time we experience that measurements were performed before which showed a ‘problem within the low frequency range at 40 or 60 Hz’. Without an exact description of the measuring method, the condition of the control room at the time of the measurement as well as exact measurement values, measurements are just useless. All of the measurement results which we have determined are therefore displayed, evaluated and explained in a detailed report.

We will be pleased to advise you about reasonable measurements for your control room.
>> Contact