USL JSD-60 Manual - Manual (Page 29)

Page 29
8.10.3 Equalizer Tab
The JSD-60 equalizer allows the frequency response of the JSD-60 to be adjusted for the acoustics of the room. The
RTA screen shows the measured sound pressure level (SPL), the measured level in each 1/3 octave spectrum band,
and limit lines for the desired equalization. By default, the limit lines correspond to the SMPTE ST 202:2010 limits
for a 500 seat auditorium. Other limit sets can be displayed (see Curve File, below). The equalizer tab also allows
access to the automatic equalization feature of the JSD-60.
RTA Channel Select Buttons
Channel select buttons are along the top of the RTA window. These select which speaker the generator is driving
and which channel the equalizer controls are adjusting. If an external pink noise generator is to be used with the
internal RTA, enable the internal pink noise generator, then disable it. Enabling the internal pink noise generator
configures the internal RTA for proper operation.
RTA View Controls
To preserve screen real estate, the working area for the RTA data displayed is maximized. When the equalizer tab
is selected, the size of the tab is increased by collapsing the input format buttons view. As the mouse is hovered
over the RTA graphical plot area, a set of controls is revealed. The controls are zoom, dB step size, decay rate,
plotting data offset, and x-curve offset. Use the Zoom buttons to enlarge or reduce the text within the RTA display
area. Use the dB/step selector to adjust the vertical resolution as required view all bands on screen while
providing the best vertical resolution. Make initial adjustments with a fast decay time. The fast decay time
provides a faster update, but a less stable display. As you close in on the final adjustment of the equalizer, increase
the decay time towards maximum to provide a stable display and precise indication of the equalization. Use the
Data Offset control to slide the RTA data up and down as required to place it within the X-curve limits. Similarly,
the X-Curve control can be used to move the limit curves up and down to best fit the RTA data.
SPL Meter
The auditorium SPL is visible along the bottom of the GUI window, no
matter which tab is selected. The display will show "SPL Uncalibrated"
until the SPL meter is calibrated by reading in an existing microphone
calibration file or adjusting the SPL calibration with a reference pink noise
level. The SPL meter uses a C-weighted filter as per ANSI S1.4-1983.
Microphone Calibration
Press this button to calibrate the microphone driving the RTA. Turn on pink
noise in the auditorium. Adjust the Microphone Gain control until the
indicated SPL matches the SPL indicated on a reference meter. Press Save to
save this calibration to a file. The file name might consist of the manufacturer's model number and microphone