SP395 SoundPro Audio Integrator
Form7492
Operation Manual
40
12.
Run/Stop
– Starts and stops the ETG function. – Click on this field to turn On the ETG
function to run the test and Off to Pause the current display. When Run is selected, the test
pulses the room with sound energy and collects the resulting energy decay data. Select
Pause to stop the test and "freeze" the currently displayed graph. This allows you to make
cursor measurements and RT calculations, and to save the graph to memory.
The display graphs the decay of the test pulse, as measured at the microphone. If the graph
does not show a decay, the test pulse may be too quiet compared to the noise in the room,
or the graph width may be too short.
13.
Cursor level dB
– indicates level dB of sound indicated at position of cursor.
14.
Ending Graph Time or Distance
– Stop the test when you have a good graph, and use
the cursor control field to move the Measurement Cursor. The time and level of the cursor
position are displayed below the graph. Measure any peak directly, to compute room
reflections or to phase speaker arrays.
To move the Measurement Cursor, highlight the "Measurement Cursor" field and click on
it (underline). Rotate the control knob to move the Measurement Cursor and read the
corresponding time/distance and dB level.
Memory
Energy-Time graphs can be stored in any of the 40 non-volatile SP395 memories, using the
memory control icons in the center of the bottom toolbar. To access the memories, follow these
steps:
-
Select a memory number.
Use the memory number field to select a memory number.
When the memory number field is selected, the type of memory stored (or “---” if empty)
appears on the bottom of the graph. The memory type for the FFT Analyzer is labeled
“FFT.”
-
Store to memory.
Click on the S (Store) icon to store the function data to the current
memory number.
-
Recall from memory.
Click on the R (Recall) icon to recall function data from the current
memory number. If the data type does not match the current function, a “Wrong type” error
message will appear momentarily. A recalled graph can be analyzed exactly the same as a
live graph - by changing the octave band filter size, graph amplitude range, and using the
cursor to read individual band frequencies and dB levels. Memory data can also be
transferred to a PC using the Transmit Data function.
-
Clear memory.
Click on the C (Clear) icon to clear data from the current memory number.
ETG Operation
Producing an Energy-Time Graph
(follow these setup steps for all ETG applications.)
1.
Trigger Mode.
Select “Int” (Internal) to set the SP395 to generate its own excitation pulse.
Plug any of the SP395 audio output into an amplifier and speaker and turn the level down at
the amplifier!
2.
Select “Ext”.
(External) if you wish to trigger the ETG using a external signal, such as a
handclap or starter pistol.
3.
Connect the SP395 Output to the amplifier input (for internal trigger).
Connect a cable
from an SP395 output connector to the input of the audio amplifier. Apply the signal to each
speaker individually.
Caution: Preset the amplifier gain to minimum to prevent speaker
damage when the ETG test is turned on.
You will not hear an output from the speakers until
the test is turned on.