6
Figure 16. Phase and amplitude response of the
LSR6328P system.
Figure 17. Second and third harmonic distortion in
the LSR6328P, 96 dB and 102 dB SPL at 1 meter.
Figure 18. LF 24- or 36-dB/octave alignment choice
for LSR6328P; HF
±
1 dB choices.
Figure 19. Boundary compensation curves
for the LSR6328P.
way system. This can be seen in Figure 16, where the
phase plot has a slight curve in the range between 200
Hz and 2 kHz. Note however that the total range of
phase shift, from low to high frequencies, is the same
as that of the LSR6332.
Distortion:
Distortion curves at 96 dB and 102 dB, both at one
meter, are shown in Figure 17. At 96 dB, the distortion
at 70 Hz and above is less than 3%, while at 102 dB it
is less than 9%. Excellent performance for a 2-way
system with a 200 mm (8 in) diameter LF driver.
LF and HF Contour Controls:
The LSR6328P has a number of user response
options that are accessible via DIP switches on the
rear panel. Figure 18 shows the effect of an LF
alignment switch that converts the normal 24 dB/
octave response to 36 dB/octave. 24/dB/octave is the
“natural” alignment of a ported system, but it allows
subsonic disturbances to pass through the system.
When that position is engaged, the user can observe
the excess cone movement caused by LF noises or
disturbances that could be objectionable in a
recording. Normally, the “VLF Protect” switch is
engaged to remove these effects from the monitor
system. There are three HF response positions: flat,
+1, and
−
1, for fine-tuning the system to the working
environment.
Boundary Compensation:
The LSR systems are designed to exhibit flat LF
response when placed in a free-standing position
away from a wall or corner. Using DIP switches, a
broad LF cut of 1.5, 3, or 4.5 dB can be introduced into
the LSR6328P system, as may be required, when the
system is operated in positions close to a wall, on a
work surface, or on the meter bridge of a console.
When the system is positioned adjacent to a boundary
it may be beneficial to introduce a 1.5 dB cut, while
placement near a corner may require up to 4.5 dB of
cut. Figure 19 shows the effects of these curves. For
essentially the same purpose, the LSR6312SP has a
boundary compensation curve that introduces a 2-dB
cut at 50 Hz when that system is positioned against a
wall or corner.
71800_JBL.TechNote
8/26/04, 7:58 AM
6
