mi niDSP Ltd, Hong Kong /
/ Features and speci fi cations subject to change wi thout pri or noti ce
36
5
A
COUSTIC MEASUREMENT
To obtain most accurate equalization results with the nanoAVR, acoustic measurement will be required. This
section provides a brief introduction. For more information, see the
section of the miniDSP.com
website.
5.1
W
HAT IS ACOUSTIC MEASUREMENT
?
An audio or home theater system has a frequency response on each channel, which includes the response of the
electronics, the loudspeaker, and the listening room. In order to understand how these all combine to affect the
sound heard by listeners, an acoustic measurement using a suitable microphone and computer software is
required.
The figure below shows a typical frequency response measurement for the bass region, using the freeware
program
. In this example, we are equalizing the subwoofer channel, so the frequency scale
from left to right progresses from 10 Hz to 300 Hz. The height of the solid red line indicates the measured SPL
(sound pressure level) at each frequency.
Where there are anomalies such as peaks in the response, these can be corrected electronically in the nanoAVR.
In the graph, the blue line shows the measured frequency response after correction with the parametric
equalizer (PEQ) on the subwoofer channel.
Figure 1. Sample bass frequency response measurement, before and after applying PEQ
