Yamaha SPX900 Operation Manual - page 14
Reverberation is the warm musical “ambience” you
experience when listening to music in a hall or other properly-
designed acoustic environment. The SPX900 offers several
different reverb effects, simulating types of reverberation you
would experience in halls, in smaller rooms, reverb effects
ideally suited to vocals, the type of reverberation produced
artificially by a plate reverberator.
PARAMETERS ACCESSED BY THE PARAM KEY
Reverb Time (REV TIME):
0.3 – 480 seconds (1. REV1 HALL, 2. REV2
HALL&GATE, 7. REV7 VOCAL 1,
8. REV8 VOCAL 2)
0.1– 480 seconds (3. REV3 ROOM 1,4. REV4
ROOM 2,5. REV5 ROOM 3,9.
REV9 PLATE, 10. REV10
PLATE&GATE)
The length of time it takes for the level of reverberation at
1 kHz to decrease by 60 dB – virtually to silence. In a live
setting, this depends on several factors: room size, room
shape, type of reflective surfaces, and others.
High Frequency Reverb Time Ratio (HIGH): 0.1 – 1.0
Natural reverberation varies according to the frequency of the
sound. The higher the frequency, the more sound tends to be
absorbed by walls, furnishings and even air. These two
parameters allow alteration of the high-frequency and low-
frequency reverb times in relation to the overall reverb time.
Diffusion (DIFFUSION): 0 – 10
The complexity of the many reflections that make up
reverberation varies according to the shape of the room and its
contents. In the SPX900 the term “diffusion” refers to the
complexity of these reflections. If the DIFFUSION parameter
is set to “0,” minimum complexity and therefore a clearer,
more straightforward reverb effect is produced. As the
DIFFUSION value is increased, the complexity of the
reflections increases producing a thicker, richer sound.
Initial Delay (INI DLY): 0.1 – 200.0 milliseconds
This represents the time delay between the direct sound of an
instrument in a concert hall and the first of the many
reflections that make up reverberation.
High-pass Filter Frequency (HPF FRQ.): THRU,
32 Hz – 1.0 kHz
Permits rolling off the low-frequency content of the reverb
signal above the set frequency. The HPF is OFF when set to
THRU.
Low-pass Filter Frequency (LPF FRQ.): 1.0 – 16 kHz,
THRU
Permits rolling off the high-frequency content of the reverb
signal above the set frequency. The LPF is OFF when set to
THRU.
PARAMETERS ACCESSED BY THE INT PARAM
KEY
0
Early Reflection/Reverb Balance (ER/REV BAL.):
– 100%
This parameter determines the level balance between the
early-reflection portion and final reverberation portion of the
reverb sound. At 100% only the early-reflection sound will be
produced. At 0% only the final reverberation sound will be
produced. A setting of about 50% produces both the early-
reflection and final reverberation sounds at equal level.
Reverb Delay (REV DLY): 0.1 – 100.0 milliseconds
Sets the delay between the beginning of the early reflections
— the initial group of sparse reflections that precede the dense
reverb sound — and the beginning of the reverb sound.
Density (DENSITY): 0 – 4
This parameter determines the density of the reverb
reflections (i.e. the average amount of time between
reflections). A setting of 1 produces minimum reverb density
for a more spacious sound, while a setting of 4 produces the
most dense, “tightest” reverberation.
Trigger Level (TRG. LEVEL): 0 – 100
Determines the level of the input signal required to trigger
“opening” of the reverb program gate. At 100% only very
high-level input signals will trigger the gate, while at 1% even
the tiniest input signal will trigger the gate.
Trigger Delay (TRG. DLY): -100 – +100.0
milliseconds
Produces a delay between the time at which the gate is
triggered and that at which it actually opens.
Hold Time (HOLD): 1 – 24,000 milliseconds
Determines how long the gate stays open. allowing the signal
to pass.
Release Time (RELEASE): 3 – 24,000 milliseconds
Determines how long it takes for the gate to close fully after
the HOLD TIME has ended.
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