What we do

We visit your room to collect a detailed set of quantitative acoustical measurements. These include: frequency response (1/3rd octave from 20Hz to 20kHz and 1/24th octave from 20Hz to 300Hz); the energy time graph (ETG); and reverberation time (RT60). We use precision measurement tools including the Beyer MM-1 Measurement Microphone, ARTA and Room EQ Wizard software.

Why we do it

There are three different measurements which are particularly useful in helping to identify opportunities for improvement.

The first is the frequency response, which is a plot of energy in decibels (dB) against frequency in Hz. Most of us should be familiar with these as they are often displayed in equipment reviews.

Example of Frequency Response Measurement used to identify response anomalies. Response variations of +/-10db through the bass region below 300hz are clearly visible. A +10db difference is roughly equivalent to someone perceiving the sound as being twice as loud.

The second is the energy time curve, which is a plot of amplitude in db against time (typically measured in milliseconds). An energy time curve shows how sound energy decays in a room. From an analysis of the energy time curve much can be deduced, including the level of reflections relative to the direct sound and the time it takes for sound to decay within the room.

Example of Early Reflection Analysis used to identify reflected sounds impacting focus. There are few strong direct reflections in this measurement, however sound is not decaying very fast, which will be heard as a blurring of the soundstage and loss of focus.

The third is a combination measurement, which shows time, energy and frequency (TEF) all together. There are many ways to look at these measurements, one is the waterfall diagram, another is a spectral decay diagram. Resonances from room modes can be very quickly identified from this measurement.

Example of Spectral Decay Analysis used to identify resonant frequencies. Here we can see clear evidence of room modes at work at 33hz, 60hz and 87hz. Notes at these frequencies take much longer to decay than notes at other frequencies. This will be heard as bass boominess and will also damage clarity due to masking of low level detail.

What you get

Typically we produce a 10-15 page report (the 'Acoustic Diagnosis Report') in which the findings from the design review, measurements and critical listening are contained together with our improvement recommendations.