Monopole reference source - Qref
The Qsources Qref is a unique reference sound source; a monopole and extremely stable. Designed for placement against a larger surface in any inclination.
As a sound power reference source (ISO 2629) it is used for various applications, including regular verification (calibration) of noise test rooms for products like pumps, ventilation, network servers, for on-site indirect machinery sound power determination (ISO 3747), for an-echoic and reverberation room verification. But also full chain, from hardware to software, verification (calibration) of large microphone arrays is possible, room acoustics model correlation, and for Statistical Energy Analysis applications (SEA).
As a constant volume acceleration sound source the Qref is ideal for isolation testing of vehicles, elevators, machinery cabins. It supports basic and fast inverse sound source level estimation (without phase), large vehicle “pass by noise” or noise emission acoustic transfer (without phase)and Statistical Energy Analysis applications (SEA)
The Qref stands out from traditional sound power reference sources due to its small size, monopole character, high output, low weight, inclination flexibility and precise signal control.
Features
light weight portable, efficient set-up, easy positioning in any inclination
market unique sound power reference source
flat equalized output spectrum 50-8000 Hz third octave bands
high acoustic impedance allowing application in smaller spaces
Exceeding requirements for ISO 3747 / 6926
for (basic) use as a constant volume acceleration sound source
predictable stable volume acceleration level in all third octave bands without a real time volume acceleration signal
Measurement techniques
Test-room calibration and regular re-calibration
Machinery sound power emission following ISO 3747
Inverse sound power, or volume acceleration identification (without phase)
Room acoustic transfer measurement
Any measurement that requires a high sound power level
Main characteristics
pink noise, white noise and sine sweep
fully equalized equal level in all third octave bands
audible warning signal when out of its stable working zone
+-110 mm. diameter
Extreme lightweight 1.5 KG
Extended frequency range: 50-8000 Hz
Core frequency range: 100-6300 Hz
Overall sound power level of +-92 dB Lw, pink random
requiring a large flat surface to act correctly as power reference
surfaces smaller than an acoustic wavelength limit the frequency range to higher frequencies
correct volume acceleration source, even on smaller surfaces down to 30 cm
Functional only as a set, Qref with a dedicated version of the Qam amplifier
Accessibility
Depending on your region the Qref Qam set is marketed in cooperation with a selected local partner or available directly from Qsources
*What is core frequency range for sound sources?
In the core frequency range a close approximation of omni-directionality and high output can be expected. Or in case of sources for ISO standard regulated requirements, like for building acoustics applications, the source will be well within the ISO requirements.
**What is extended frequency range for sound sources?
Including the 50 Hz, 63 Hz and 80 Hz third octave bands in equalized random signal reduces the maximum level by approximately 4 dB. For the Qmir1 the level stability of the lowest and highest third octave bands is not at the same level as the third octaves within the core frequency range. The highest third octave band(s) do not reach the same level of omni-directionality.
