KDFX Reference
KDFX Algorithm Specifications
10-209
954 Compress/Expand
955 Comp/Exp + EQ
A stereo soft-knee compression and expansion algorithm with and without equalization
PAUs:
2 for Compress/Expand
3 for Cmp/Exp + EQ
These are a stereo compressor and expander algorithms. One version is followed by equalization and the
other is not. The algorithms compress the signal level when the signal exceeds a compression threshold
and expands the signal when the signal falls below the expansion threshold. The amount of compression
and/or expansion is based on the larger magnitude of the left and right channels.
Compression is expressed as a ratio: the inverse of the slope of the compressor input/output characteristic.
A compression ratio of 1:1 has no effect on the signal. An in
fi
nite ratio compresses all signal levels above
the threshold level to the threshold level (zero slope). For ratios between in
fi
nite and 1:1, increasing the
input will increase the output, but by less than it would without compression. The compressor is a soft-
knee compressor, so the transition from compressed to linear is gradual.
The amount of expansion is expressed as an expansion ratio. Expanding a signal reduces its level below
the threshold. The expansion ratio is the inverse of the slope of the expander input/output characteristic.
An expansion ratio of 1:1 will have no effect on the signal. A zero ratio (1:
∞
), will expand all signal levels
below the threshold level to the null or zero level. (This expander expands to 1:17 at most.) Thresholds are
expressed as a decibel level relative to digital full-scale (dBFS) where 0 dBFS is digital full-scale and all
other available values are negative.
Figure 10-109 Compressor/Expander (optional EQ not shown)
R Input
L Input
Maximum
Magnitude
Expander
Computation
Compress/
Expand
Compress/
Expand
Compress/
Expand
Compress/
Expand
Magnitude
Maximum
Delay
Delay
Computation
Compressor
Feedback/Feedforward
Switches
L Output
R Output
Out Gain
Summary of Contents for K2661
Page 18: ...2 4 LFOs LFO Shapes...
Page 34: ...3 16 DSP Algorithms...
Page 54: ...5 4 MIDI Note Numbers Note Numbers for Percussion Keymaps...
Page 72: ...7 10 System Exclusive Protocol K2661 System Exclusive Implementation...
Page 82: ...9 4 Upgrading Sample Memory Choosing and Installing a SIMM for K2661 Sample Memory...
Page 334: ...10 252 KDFX Reference KDFX Algorithm Specifications...
Page 340: ...11 6 Glossary...
Page 382: ...12 42 Triple Modular Processing Alphanumeric Buttonpad Entries for DSP Functions...
Page 392: ...B 6 SysEx Control of KDFX MSB and LSB...
Page 442: ...D 20 Contemporary ROM Block Objects Controller Assignments Contemporary ROM Block...
Page 490: ...H 12 General MIDI Standard Mode Controller Assignments...
Page 492: ...I 2 Live Mode Objects Live Mode Programs...
Page 498: ...K2661 Musician s Reference Index...
Page 500: ......