Welcome to RM707, our newly configured spatial audio lab! The loudspeaker installation here allows us to pan sounds around in full surround sound, using a system known as ambisonics. One of the major drawbacks to traditional surround sound formats (5.1, 7.1 etc.) is that they’re channel based, meaning that the loudspeakers have to orientated in a particular way (to ITU spec), and when mixing audio around there are a very limited number of positions to work with. Ambisonics allows us to decode audio to any loudspeaker configuration, including loudspeakers positioned at different heights, as well as being able to pan sounds to positions in space rather than just to particular channels.
The modern sound level meter is a powerful tool with many useful functions, but what are the most important things to know? This post aims to act as a simple to follow guide.
The World Health Organisation states that loud noise is the single biggest preventable cause of hearing loss in the UK. Due to advances in portable media player technology, users are now able to store and play music for much longer. Due to this, there is a huge potential risk for overexposure to noise using these devices. It is now estimated that over 4 million young people in the UK are suffering with the effects of noise induced hearing loss from listening to amplified music in the UK.
Solent Acoustics has recently taken delivery of an impedance gun kit from Microflown, used for the in-situ measurement of sound absorption coefficient.
The kit contains the impedance gun itself, which is constructed of a loudspeaker and PU Probe (for the measurement of both pressure and particle velocity), and a Scout V2 USB data acquisition system. Software provided by Microflown allows for the calculation of acoustic absorption coefficient from the measurement of pressure and particle velocity, which also allows for measurement of acoustic intensity.
Solent Acoustics has recently taken delivery of a brand new intensity probe kit from Brüel & Kjær. The kit comprises of a phase and amplitude matched, class 1 microphone pair (Type 4197), a 2 channel preamplifier system for housing the microphones, a calibrator adapter, windscreen, extension stem, earphones, tape measure and carrying case. The system is compatible with the Hand-held Sound Intensity System Type 2270 for measuring sound intensity.
The Soundfield SPS200 is a new type of microphone to Solent Acoustics which can be used for capturing “3D” surround sound.
Solent Acoustics has recently acquired a laser doppler vibrometer!
Produced by Polytec, the PDV-100 is capable of non-contact velocity measurement from 0 to 22kHz with a range of around 30m. The laser itself is eye-safe, making it perfect for use in student projects. It is also very portable which allows us to carry out measurements in a wide range of locations, even with limited access.
The LDV can be used for almost any vibration measurement without providing an additional mass to the subject under test as an accelerometer would. This increases the accuracy of vibration measurements while also allowing us to investigate things not possible with accelerometers, such as the sound of a spiders mating dance!
For more information on the PDV-100 read the data sheet provided by Polytec, found here: http://goo.gl/wisNsw