CLIOwin 6.5 PCI User's Manual - Audiomatica Srl

0 2.03mS 7.26mS 10mS
SPEAKER
DIRECT SOUND
70 cm - 2.03mS
MIC
FIRST REFLECTION
250 CM - 7.26mS 120 cm
ABSORBING MATERIAL
Figure 10.11
Any other reflecting surface is farther than the floor. If the microphone is directly
connected to the CLIO board remember to switch the microphone power supply
on. Also, very important, remember to type in the correct microphone sensitivity in
the microphone Dialog Box. The last item is crucial for setting the correct measurement
level. We already dealt we level before. Here things are more dangerous. Supposing the
amplifier used has a gain of 30dB, a common value, leaving CLIO output level to 0dB
will cause the amplifier to deliver the equivalent of circa 40W/8Ohm continuous. If the
amplifier handles this power you will for sure burn your tweeter. If the amplifier is of
lower power it will saturate and burn your tweeter even faster. To avoid this
embarrassing event, do as follow: enable CLIO input auto-range, open the Multi-Meter
and select Pressure from the Parameter Drop Down. You will get the reading of your
environmental noise. Fig.10.12 shows ours, we hope yours is lower.
FLOOR
Figure 10.12 and 10.13
Now set CLIO output level to a very low value, -30 to -40dB. Start the MLS signal and
increase CLIO output level until you read 85 to 90 dBSPL as in Fig.10.13. This holds if
you placed the microphone 70cm to 1m distant from the speaker. Now go back to the
Chapter 10 - MLS 93