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Operating Manual - PROTEA SYSTEM II  4.24C  Crossover / System Processor

6

4.6  Audio Functions

4.6a  Gain

Input and Output Gain are

separately adjustable from -40dB to
+12dB in 0.1dB increments.

The output gain menu also

provides for selection of input
source(s) for a given output channel,
as well as polarity of the outgoing sig-
nal.  Input signal sources are A, B, C,
D, A+B, C+D, all four inputs com-
bined, or no input (Off).  Keep in mind
that two signals which share significant
content, such as a stereo source, will
be up to 6dB louder when combined.

4.6b  EQ

The Protea 4.24C EQ section

offers full parametric EQ as well as
1st and 2nd order shelving filters on
inputs and outputs.  Each input chan-
nel has six selectable EQ filters, while
each output channel has four select-
able EQ filters.  In all cases, each fil-
ter is selectable between parametric
(PEQ), 1st order Low Shelf (LS1), 2nd
order Low Shelf (LS2), 1st order High
Shelf (HS1), and 2nd order High Shelf
(HS2).

Shelving EQ filters:  1st order fil-

ters use a gentle 6dB per octave slope, while
2nd order filters use a 12dB per octave slope
for more a pronounced boost or cut.  All
shelving filters have a boost/cut range of +/-
15dB.  Low shelving filters have a frequency
range from 19.7Hz through 2kHz, and the
high shelving filters range from 3.886kHz
through 21.9kHz.  Shelving filters are most
useful as broad tone controls to boost or cut
the high end or low end of an audio signal's
frequency content.  Because they affect a
wider spectrum of audio, they are not as suit-
able for feedback control as parametric fil-
ters.

Input Gain

Channel A-D

Level

-40 to +12

Input Gain LCD Display

GAIN A

  0.0dB

Output Gain LCD Display

Output Gain

Channel 1-8

Level

-40 to +20

Signal Source

A+B,C+D,All

Output

Polarity

A,B,C,D

GAIN 1

  0.0dB

Source:A

Pol:Normal

200Hz

2KHz

20KHz

20Hz

0dB

-10dB

-20dB

+10dB

+20dB

-30dB

Low Shelf

High Shelf

4. 24C Shelving Filters

2nd Order Filter

1st Order Filter

Ch. A-D EQ

Ch. 1-8 EQ

EQ +/-

Level

EQ LCD Display

Parametric

High Shelf-2nd

Parametric

Bandwidth

Low Shelf-1st

PEQ, LS, HS

Frequency

6 Input Fltrs

4 Outpt Fltrs

Low Shelf-2nd

High Shelf-1st

EQ 1

  0.0dB

Filtr:1-PEQ

1000Hz 1.00o

Summary of Contents for PROTEA SYSTEM II 4.24C

Page 1: ...O INC 847 Holt Road Webster NY 14580 9103 Phone 585 872 0010 Toll Free 800 828 6308 Fax 585 872 0739 w w w ashly c o m 4 24C 24 Bit Digital Crossover and System Processor Operating Manual Digital Audi...

Page 2: ...4 1 Function Keys and Data Wheel 5 4 2 Presets 5 4 3 Input Select 5 4 4 Output Select 5 4 5 LED Indicators 5 4 6 Audio Functions 6 4 6a Gain 6 4 6b EQ 6 4 6c Delay 7 4 6d Crossover 8 4 6e Limit 10 4 7...

Page 3: ...esence of important operating and maintenance instructions in the literature accompanying the device The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the u...

Page 4: ...control parameters Five segment LED arrays on each input and output provide audio level information and mute status Protea System Software The computer interface uses Ashly PROTEA SYSTEM SOFTWARE for...

Page 5: ...powered up the last working preset is loaded displaying the number and name last used before the unit was turned off Any modifications made to that preset before saving it will remain in the working...

Page 6: ...ters 1st order fil ters use a gentle 6dB per octave slope while 2nd order filters use a 12dB per octave slope for more a pronounced boost or cut All shelving filters have a boost cut range of 15dB Low...

Page 7: ...ndwidth is adjustable from about 1 64 octave to four octaves and the lower the bandwidth the less audible the filter action will be Finding the problem frequency is relatively easy but finding the bes...

Page 8: ...tput delay Note Although delay in the 4 24C is adjusted only by time the corresponding dis tance in both feet and meters is always shown as well 4 6d Crossover Xover Crossover functions on the Protea...

Page 9: ...per octave Butterworth crossover filters one of the outputs must be inverted or else the combined response will result in a large notch at the crossover frequency Bessel These filters as implemented o...

Page 10: ...ss some of the initial transient Similarly a very short release time can make the audio sound uneven while a very long release time can create pumping or breathing characteristics depending on the kin...

Page 11: ...pressing the Copy button a second time to complete the action 4 7d Mute The Protea 4 24C allows the user to mute both inputs and outputs When muted an input or output s red Mute LED is lit When an inp...

Page 12: ...ady saved within the 4 24C Other function messages are system exclusive A comprehensive PDF document detailing complete MIDI implementation of Protea products is available on the Ashly Web Site MIDI D...

Page 13: ...l assignment within the 4 24C is done in the Util menu and should match the MIDI channel selected within the crossover section of Protea System Software Note If the 4 24C is connected to the PC RS 232...

Page 14: ...gram is the same whether from the web site or from a disk and is called Pssinstl exe There is currently no version available for Mac computers To install Protea System Software double click on Pssinst...

Page 15: ...roperly set up gain structure Do not use the 4 24C for dramatic increases in level but rather optimize the signal source for a nominal 0dBu output Forgot the password See section 4 7e 7 2 RS 232 MIDI...

Page 16: ...9 7Hz to 21 9kHz Off Available Filter Types 12dB Oct Butterworth 12dB Oct Bessel 12dB Oct Linkwitz Riley 18dB Oct Bessel 18dB Oct Linkwitz Riley 24dB Oct Butterworth 24dB Oct Bessel 24dB Oct Linkwitz...

Page 17: ...nd return the warranty card that came with your product Fill out the information below for your records Model Number _____________ Serial Number ________________ Dealer __________________________ Date...

Page 18: ...____ Bandwidth PEQ _________ EQ Filter no 3 Filter Type ______________ Frequency__________ Boost Cut ________ Bandwidth PEQ _________ EQ Filter no 4 Filter Type ______________ Frequency__________ Boos...

Page 19: ..._____ Output Delay ______________________________ Output EQ EQ Filter no 1 Filter Type ______________ Frequency__________ Boost Cut ________ Bandwidth PEQ _________ EQ Filter no 2 Filter Type ________...

Page 20: ...Limiter Mute 7 HpfLpf EQ Delay Gain Limiter Mute 4 HpfLpf EQ Delay Gain Limiter Mute 6 HpfLpf EQ Delay Gain Limiter Mute 8 HpfLpf EQ Delay Gain Limiter Mute A D Input Mute Input EQ Input Meter LEDs I...

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