100 Things #55: Make RT60 Room Acoustics Measurements With SoundCheck

SoundCheck makes fast, reliable RT60 room acoustics measurements with fully calibrated signal paths, ensuring accurate results. This helps product designers quantify how their devices will interact with the acoustics of a particular type of room, and simulate real-world conditions to test their devices.

Making RT60 Room Acoustics Measurements with SoundCheck

Learn more about making RT60 Room Acoustic Measurements

The Room Acoustics Measurement video demonstrates Room Acoustics Measurements in the First Korean Church in Cambridge, MA.

 

Video Script: RT60 Room Acoustics Measurements

Did you know that SoundCheck can make RT60 Room acoustics measurements? This helps product designers quantify how their devices will interact with the acoustics of a particular type of room, and simulate real-world conditions to test their devices.

This is particularly important for products such as smart devices and communications devices where the user may place them in a variety of locations. Test environments to simulate these must be carefully designed and fully characterized, with known reverberation time – that’s the signal decay time,  and clarity – the ratio of early reverberation to later reverberations.

The difference between SoundCheck and the more basic room acoustics packages out there is that SoundCheck makes all the measurements with advanced filtering algorithms and fully calibrated signal paths. This is important because acoustic measurements are sensitive to background noise and simulated real-world measurements are typically performed in noisy rooms or environments, for example, a kitchen or train station. Calibrated measurements allow us to measure the noise floor and set the speaker level accordingly for accurate RT60 measurements. Plus, if you’re serious about smart device measurements you probably already have SoundCheck, so it makes sense to keep everything in the same test environment.

Let’s take a look. Here we have a Bruel & Kjaer omnidirectional sound source. These speakers are all connected in parallel to radiate sound evenly and in-phase in all directions. We’re going to capture the sound with 4 of our own SCM microphones, connected to the AmpConnect 621 audio interface which has 6 input and 2 output channels. The test sequence (which is available free of charge on our website) plays a continuous sine sweep out of the omnidirectional sound source and the room response is recorded with the four microphones. This test signal has excellent noise immunity and it’s easy to separate the fundamental from the harmonics to minimize distortion effects on the measurements. Room acoustics values are then determined using a backwards integrated impulse response method. This method is very fast and requires just one measurement at each location. The results from the four microphones are averaged and displayed as single lines on the graph for T20, T30 and T60 measurements, as well as all 3 clarity curves.

If you’d like to learn more about this optional module, or download the test sequence, visit our website, www.listeninc.com.