SP395 SoundPro Audio Integrator
Form7492
Operation Manual
59
field) than the Max Noise Level reading. If the Min Room level is greater than 50 dB, you
need to lower the ambient noise for best test results. To store the Min Room level, set the
Test Control field to "
Set Min,
" then click the Test Control field.
6.
Maximum Room Noise Level –
This is the maximum sound energy in the room with the
octave band pink noise test signal applied. Adjust the amplifier's volume and/or SP395
generator output to increase the sound level to 80-90 dB to achieve the highest possible
decay range.
You may want to wear ear plugs.
7.
Decay Range –
The dB difference between the Max Noise and Min Room levels for the
selected octave band. This is the range of the RT60 test. Try to achieve the highest range
possible by reducing room noise or increasing the octave band pink noise. A range of
30dB or higher is required to perform the ALCOM calculation.
8.
Room Dimension length –
Enter length of room in which the measurement is to be taken.
9.
Room Dimension height
– Enter ceiling height of the room in ft. or meters.
10.
Room Dimension width
–Enter width of the room in ft. or meters.
11.
Sound Travel Distance Spkr to
Mic –
Enter the distance from the speaker to the listener
or microphone.
12.
Test Interval
– Time interval of cycling octave band noise on and off and updating
measurement results. The test continues to repeat in the “RUN” mode.
13.
Critical Distance Calculation
– Determined by mathematical formula based upon room
dimensions, speaker to listener distance, and RT60 results.
14.
RT60 Measurement Readout
– The RT60 calculated measurement of the room.
Indicates the extrapolated time for the sound to decay 60 dB (RT60) in the measured
octave band.
15.
ALCONS Measurement Readout
– ALCON test measurement readout in %.
16.
Generator
– On/off function overridden during ALCONS test. Level Output is adjustable.
ALCONS Function Operation
1.
Connect output.
Connect an amplified speaker to any SP395 output. Put this at the
“speaker” location.
2.
Position microphone.
Set up the SP395 microphone at the “listener” position. Use a
stand, if possible.
3.
Units.
Select the unit of measurement used to specify the speaker to microphone (ft or
m).
4.
Octave Band.
Select the octave band. 2 kHz is recommended, although 500Hz and 1
kHz are also available.
5.
Room Dimensions.
Enter the room dimensions (length x height x width) in the units
previously selected.
6.
Speaker Distance.
Enter the distance between the speaker and the microphone. Needed
for critical distance and ALCONS calculations.
7.
Time Interval.
Enter the RT60 pulse time interval. This is related to the RT60 time.
Ensure that the interval time is greater than the expected or measured RT60 time for the
room, to allow the pink noise pulse to decay as much as possible.
8.
Mode.
Now, move to the “Hld” field, and change this to “Min”. Allow several seconds
for the SP395 to measure the noise floor in the room in the octave band selected.
9.
Generator Level.
Click the “Min” field to “Max”. The generator is now turned on.
Increase the volume level in the room using the generator level icon or the amplifier
volume control to get as much level as possible without overloading the amplified
speaker. The available decay range is computed and displayed.
