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PRIR OPTIMISATION
Sweep options
For the
SPK
(PRIR) measurement, The Realiser allows the user to choose the length of the sweeps and
whether sweeps are repeated. Using longer and repeated sweeps improves the signal-to-noise ratio of
the measurement in most situations.
Press
MENU-SPK
. The screen says:
>SAVE AT END:YES
LOOK ANGLES:AZI
EXCITATION MENU
SPEAKER MODE MENU
Choose
EXCITATION MENU
. The screen says:
>TYPE:SWEEP 3s
AVG LOOK C:1
AVG LOOK L-R:1
POST SILENCE:1 sec
The line items work as follows.
TYPE:SWEEP
--
3s
or
12s
. The three-second default sweep is used for demonstrations, and in
most environments yields a very good result. The twelve-second sweep is recommended for the
measurements you intend to use and archive.
AVG LOOK C:
-- sets the number of repetitions for the looking-centre sweeps. The choices
are
1
,
2
,
4
, or
8
repetitions. In a quiet environment, the improvements using more and more
repetitions are small and of course multiply the total time required for the measurement. In
rooms with short to medium path lengths from speakers to listener, a user might try two
repetitions at twelve seconds per sweep for critical measurements. Do
not
use repetitions (set
AVG LOOK C
:
to
1
) for long path lengths such as found in a cinema.
In addition to the options
1
,
2
,
4
, and
8
, there are the options
1*
,
2*
,
4*
and
8*
.
1*
is not to
be used.
2*
,
4*
and
8*
are again multiple sweeps, but there is a pause after each sweep, and
the next sweep is triggered by pressing
OK
. This allows the speaker to be moved to another
location in between sweeps, so that multiple locations are captured and a single speaker is
“multiplied” in the PRIR. Note that the multiplied speakers are all mapped to the same channel,
and head tracking is disabled for the multiplied speakers. There are more powerful methods of
multiplying speakers so that the additional speakers are mapped to different channels and head
tracking is enabled; see PRIR Measurement Modes and Multiplying Speakers. The multiple
sweep method described here should be used specifically when the user desires the multiple
virtual speakers to be connected to the same channel and where head tracking may be
unnecessary. Creating multiple virtual subwoofers is the typical application.
AVG LOOK L-R
:
-- sets the number of repetitions for the looking-left and looking right
sweeps. Again the choices are
1
,
2
,
4
, or
8
repetitions. The looking-left and -right
measurements are less critical than the looking-centre, so one might repeat the centre
measurements and not the left and right, or, given the time and inclination, repeat both (except
with long path lengths). Again, do
not
use repetitions (set
AVG LOOK C
:
to
1
) for long path
lengths such as found in a cinema.
