Nexo NXAMP - Manuel (Page 30)

ENGLISH
PAGE
30
INSTALLATION RECOMMENDATIONS
We recommend that the system is adjusted so that arrivals from MAIN SYSTEM array and SUB
speakers are coincident at a fairly distant listening position (typically further than the mixing position).
Geometrical alignment
In the example below, r
1
being the smaller distance from MAIN SYSTEM array to listener position, and r
2
being the smaller distance from SUB to listener position, the distance difference is then r
1
– r
2
(specified
meters or feet).
r
1
> r
2
, the delay should be set on the SUB NX242 TDcontroller(s).
r
1
< r
2
, the delay should be set on the MAIN SYSTEM NX242 TDcontroller(s)
To convert the result in time delay (specified in seconds), apply:
t = (r
1
- r
2
)/C r
1
and r
2
in meters, C (sound speed) 343 m/S.
The delay parameter is set in MENU 1.2 (set the units to meters, feet or seconds according to your
preference).
However, it is a safe practice to double-check geometrical alignment with a proper acoustical
measurement tool.
Measuring and aligning phase in the overlapping region
Microphone must be set on the ground , at a fairly distant listening position (typically further than the
mixing position).
Phase must be measured with a wrapped display, and measurement must be properly windowed on
signal arriving time (same window for SUB and MAIN SYSTEM). When measurement is synchronized to
the system-microphone distance, phase can be clearly displayed in the low-frequency range.
1200 mm [47.24"]
750 mm
[29.53"]
750 mm
[29.53"]
1200 mm [47.24"]
750 mm
[29.53"]
750 mm
[29.53"]
1200 mm [47.24"]
750 mm
[29.53"]
750 mm
[29.53"]
r
2
r
1
NX242 USER MANUAL LOAD2_22
DATE : 12/3/2004