Zaxcom ZMT-421 User manual

1
USER MANUAL
Published January 2022
Firmware Version ZMT-421
ZMT4-FLEX
Transforming Audio

2
HOME SCREEN .............................................................................................................................................. 5
MAIN MENU ................................................................................................................................................. 6
MICROPHONE GAIN SET ................................................................................................................................................................6
UHF TRANSMIT FREQUENCY SET.....................................................................................................................................................6
TRANSMITTER LOCK PAGE ..............................................................................................................................................................6
SUB MENUS .................................................................................................................................................. 7
MENU GROUPS ............................................................................................................................................................................7
ACCESSING AND NAVIGATING THE MENU GROUPS ...............................................................................................................................7
ENTERING AND NAVIGATING A SUB MENU..........................................................................................................................................7
EXITING THE EXTENDED MENU.........................................................................................................................................................7
TIME CODE MENU......................................................................................................................................... 8
TIME CODE FRAME RATE SET..........................................................................................................................................................8
TIME CODE SOURCE SELECT............................................................................................................................................................8
TC JAM MODE SELECT ..................................................................................................................................................................8
MUTE TIME CODE TRANSMISSION UNTIL JAMMED .............................................................................................................................8
AUTO FRAME RATE ENABLE............................................................................................................................................................9
TRANSMIT MENU.........................................................................................................................................10
UHF TRANSMITTER POWER LEVEL SET ...........................................................................................................................................10
UHF TRANSMIT MODULATION SET................................................................................................................................................10
TRANSMITTER DISABLE -RECORD ONLY MODE..................................................................................................................................10
RECORD MENU ............................................................................................................................................11
SD CARD FORMAT ......................................................................................................................................................................11
PLAYBACK CONTROL....................................................................................................................................................................11
TIME LEFT ON CARD....................................................................................................................................................................12
AUTOMATIC RECORD AFTER BOOT UP.............................................................................................................................................12
LOW BATTERY STOP SET ..............................................................................................................................................................12
ZAXNET MENU.............................................................................................................................................13
ZAXNET MODE ..........................................................................................................................................................................13
ZAXNET RECEIVE FREQUENCY SET..................................................................................................................................................13
ZAXNET TRANSMIT FREQUENCY SET...............................................................................................................................................13
GROUP CODE SET.......................................................................................................................................................................14
UNIT CODE SET ..........................................................................................................................................................................14
ZAXNET VOTING ENABLE .............................................................................................................................................................14
ZAXNET RECEIVE BEFORE TRANSMIT TIME ......................................................................................................................................15
IFB RECEIVE PULSE SET ...............................................................................................................................................................16
RECORD BEEP SET.......................................................................................................................................................................16
AUDIO MENU...............................................................................................................................................17
HIGH PASS FILTER.......................................................................................................................................................................17
2K NOTCH FILTER.......................................................................................................................................................................17
DYNAMICS ................................................................................................................................................................................18

3
SETUP MENU ...............................................................................................................................................19
TEST TONE ................................................................................................................................................................................19
KEY LOCK ON BOOT UP...............................................................................................................................................................19
QRX /ERX FIRMWARE UPDATE ...................................................................................................................................................19
OLED BRIGHTNESS ADJUST..........................................................................................................................................................20
OLED DISPLAY DIM....................................................................................................................................................................20
INFORMATION PAGE ...................................................................................................................................................................20
HIDE ENCRYPTION MENU.............................................................................................................................................................20
ENCRYPTION CODE SET................................................................................................................................................................21
HIDE TRANSMITTER NAME MENU .................................................................................................................................................21
TRANSMITTER NAME SET .............................................................................................................................................................21
RECORDING FORMAT ..................................................................................................................................................................22
FIRMWARE ..................................................................................................................................................23
UPDATING THE ZMT4 FLEX FIRMWARE ..........................................................................................................................................23
UPDATING ERX FIRMWARE WITH A ZMT4 FLEX TRANSMITTER............................................................................................................23
UPDATING QRX FIRMWARE WITH A ZMT4 FLEX TRANSMITTER ...........................................................................................................24
OPERATING FREQUENCIES............................................................................................................................25
ZAXNET -REMOTE CONTROL AND TIME CODE .................................................................................................................................25
UHF -AUDIO ............................................................................................................................................................................25
PRODUCT SUPPORT .....................................................................................................................................27
SPECIFICATIONS...........................................................................................................................................28
ZAXCOM WARRANTY POLICY AND LIMITATIONS...........................................................................................29

4
ZMT4 Transmitter
1. Menu / Play Key
•Press it to access the next menu item.
•Press it with the CARD key to playback a segment.
2. DEC / Stop Key
•Decreases the parameters of the menu items.
•When in the home screen pressing DEC with the CARD key will stop the recording.
•When playing back in the transport control screen will cause the transmitter to stop playback.
•Press and hold while in the transport control screen will jump back to the previous segment.
•Pressing it three times quickly while in the home screen will access the sub menu.
3. INC / Record Key
•Increases the parameters of a menu item.
•When in the home screen pressing INC with the CARD key will put the transmitter into record.
•When in the transport control screen while not recording will cause the transmitter to playback.
•Pressing while playing back will advance playback, multiple presses will cause playback to advance in
larger increments.
•Press and hold while in the transport control screen will advance to the next segment.
•Press it while in the home screen will display the group and unit code and the time left on the card.
4. OLED Display
5. Card / Power Key
•Push and hold for 2 seconds to power on.
•Push and hold 3 seconds followed by a quick press of the MENU key to power off.
•Press 3 times quickly to access the sub menus.
•Press 3 times quickly to return to the home screen.
5
1
2
3
4

Zaxcom ZMT4 Flex Home Screen
5
Home Screen
Frequency - This is the transmit frequency of the ZMT4 Flex.
If the ZMT4 Flex is being used in RECORD ONLY mode “NOTX” will be displayed.
Time Left On Card - Displays the record time left on the card.
Transport Status – Displays the current mode of the recording feature.
•STOP - Recording / Playback is stopped
•REC - ZMT4 Flex is recording.
•PLAY - ZMT4 Flex is playing back a recorded audio file.
Time Code - Displays the current time code.
Modulation - Displays the transmission modulation.
Segment Number - Displays the number of recorded segments on the micro SD card. Please note that
regardless of the size of the card it is limited to 500 segments.
Battery - This displays the battery type and the approximate percentage of remaining battery power.
Audio Meter - Displays the modulation of the inputted audio signal.
SEG -
Gain - “G” Appears when the transmitter is receiving change of gain commands via ZaxNet.
Group and Unit Code - Pressing the INC key while in the
home screen will display the group and unit code and the
ZaxNet IFB status.
Time Code UBITS and Frame Rate - Pressing the DEC
key while in the home screen will display the time code, frame
rate and user bits of the time code generator. The time left on
the record card will also be displayed.
GROUP:1 UNIT:1
IFB RX FREQ: 2.404
PKTS:0000 TC:00 REM:00
TC: 09:18:05:00 23.98
UB: 00:00:00:00 (AUTO)
CARD TIME LEFT : 23H
Time Left Transport
Frequency on Card Status
Battery Level Audio Meter Gain
Indicators at -20, -10, 0 dBFS
543.2 24H STOP
09:18:05:03 ZHD48 01
G

Zaxcom ZMT4 Flex Main Menu
6
Main Menu
To cycle through the main menu press the MENU key.
Microphone Gain Set
The microphone gain is adjusted from this menu. This menu displays the gain setting in decibels and a meter
indicating the audio signal. The meter is displayed horizontally from left to right.
UHF Transmit Frequency Set
This menu is where the UHF transmit frequency is set.
•Short presses of the INC or DEC key causes the value to change by 0.1 MHz
•Holding the INC or DEC key causes the value to change by 0.5 MHz
Transmitter Lock Page
This page enables a key lock function so no parameters can be changes. When the lock page is landed on
a countdown clock will begin. After 5 seconds the transmitter will lock and the display will indicated that
it is LOCKED. If this screen is exited before the 5 seconds are up the transmitter will not lock.
To lock the transmitter before the 5 seconds press and hold the DEC key.
Pressing the INC key when the transmitter is locked will display the ZMT4’s group and unit code, its
transmit frequency and serial number. Pressing the DEC key will display the units name, battery voltage
and current record segment number.
To unlock the transmitter
•Press and hold the MENU key and press INC keys 5 times.
Or
•Powering down and reboot the transmitter.
GAIN 20 dB
TXFREQ 543.2
Countdown clock starting at 5 seconds
After the transmitter locks
LOCKED 20 dB
09:18:05:02
23.98
IFB RX
LOCK 5

Zaxcom ZMT4 Flex Menu Navigation
7
Sub Menus
Menu groups
The ZMT4 Flex has six sub menu groups
•Time Code - Changes the time code parameters of transmitter.
•Transmit - Changes the parameters of the UHF transmitter.
•Record - Changes the parameters of the on-board recorder.
•ZaxNet - Changes the parameters of the ZaxNet transceiver.
•Audio - Changes the parameters of the transmitted and recorded audio.
•Setup - Changes the parameters of the general operation on the transmitter.
Accessing and navigating the menu groups
From in the home screen press the CARD key three times, or hold the MENU key while booting up, to access
the six menu groups. Then pressing the INC or DEC key will cycle between the menu items.
Entering and navigating a sub menu
When landing on the desired menu group press the MENU key to enter that menu.
To return to the top of the menu press the MENU key to cycle to the top or press and hold the MENU key for
1.5 seconds.
Exiting the extended menu
Press the CARD key 3 times or press the MENU key to cycle through the sub menu items until HOME MENU is
displayed then press the MENU key.

Zaxcom ZMT4 Flex Time Code Menu
8
TIME CODE MENU
Time Code Frame Rate Set
The time code frame rate menu is where the time code frame rate is set.
The ZMT4 Flex will lock to and record all standard time code frame rates.
•23.98, 24, 25, 29.97DF, 29.97DF, 30 DF, 30 NDF
Time Code Source Select
The time code source menu selects how the transmitter will receive its time code.
•ZAXNET (RF) - The ZMT4 Flex will receive time code via ZaxNet from a Deva 24, Nomad, a QRX235,
IFB100/200, TRX900CL or another TRX transmitter or a ZFR recorder that is transmitting ZaxNet time code.
•AUDIO INPUT - The ZMT4 Flex, with a proper cable, will receive time code via the microphone input.
When time code is connected, it takes the ZMT4 Flex approximately three seconds to recognize the TC. The
screen will display TIME CODE followed by JAM when it is recognized. Please note that when using the
microphone input connector, the audio level of the time code signal needs to be between -30 and -10 dBFS
on the unit’s meter. Any level above -10 may cause clipping, which will prevent proper reading of time
code.
TC Jam Mode Select
This menu controls if the ZMT4 Flex will go into record when it receives a record run time code.
•AUTO-JAM NORMAL - The ZMT4 Flex will continuously jam time code via ZaxNet and will go into record
when receiving a record command via ZaxNet or if the unit is put into record manually by pressing the
CARD and INC keys simultaneously.
•AUTO-LOAD REC RUN - In Auto-Load mode the ZMT4 Flex will go into record when it detects rolling time
code and will stop when the time code stops. If time code is lost because the IFB signal is too weak the
unit will not stop but will continue in whatever state it was in until the time code signal is restored.
Mute Time Code Transmission Until Jammed
If the mute time code menu is set to ON the ZaxNet transmitter will not broadcast time code over ZaxNet
until the transmitter receives time code and jams its own internal time code generator. This prevents the
ZaxNet from sending incorrect time code to another device.
TIMECODE 23.98
GEN 09:18:05:02
TC SOURCE:
ZAXNET (RF)
TC JAM MODE:
AUTO-JAM NORMAL
MUTE TC SEND
UNTIL JAMED: OFF

Zaxcom ZMT4 Flex Time Code Menu
9
Auto Frame Rate Enable
When turned ON the ZMT4 Flex will automatically set its frame rate to the frame rate that is being
transmitted from the ZaxNet transmitter that is feeding the ZMT4 Flex. If auto frame rate is set to OFF the
frame rate will need to be adjusted manually. Please note that auto frame rate will only work when the time
code is being received over ZaxNet and will not work when time code is being received via the audio input.
AUTO FRAME RATE
ON (23.98)

Zaxcom ZMT4 Flex Transmit Menu
10
TRANSMIT MENU
UHF Transmitter Power Level Set
The UHF transmit power of the ZMT4 Flex is set from this page. The transmit power can be adjusted to
output 25, 50 or 75mW. The higher the power setting the more battery power will be required.
UHF Transmit Modulation Set
The UHF transmission modulation is the way the ZMT4 Flex sends audio to the receiver. The modulation format
is set from this menu. Please note if the transmission format that is set here, and the format set on the receiver
do not match, the receiver will be unable to decode the audio from the transmitter. Also note that after any
change to the transmit format the ZMT4 Flex will need to be rebooted by pressing the card key before the new
format takes effect.
MONO
STEREO
XR
ZHD 96
ZHD 48
Modulation Bandwidth 200 kHz 196 kHz 200 kHz 96 kHz 48 kHz
Minimum Channel to Channel Spacing 400 kHz 200 kHz 400 kHz 300 kHz 200 kHz
6 MHz TV Channel Capacity 15 30 15 30 60
Latency 3.5ms 6ms 6ms 6ms 18ms
Compatibility with a 200 Series Receiver 2 Transmitters 2 Transmitters 2 Transmitters 2 Transmitters 1 Transmitter
Transmitter Disable - Record only mode
•Record Only Mode - Will set the ZMT4 Flex to act as a standalone recorder and will not transmit any audio
over UHF. This will conserve battery power since the transmitter is disabled.
•Normal TX Mode - Will allow the ZMT4 Flex to both transmit audio and record on its internal micro SD card.
TX FORMAT:
ZHD96
PRESS CARD TO REBOOT
TX DISABLE :
NORMAL TX MODE
TX POWER: 50MW

Zaxcom ZMT4 Flex Record Menu
11
RECORD MENU
SD Card Format
This menu will only appear if a card was inserted prior to booting up
The Micro SD card is erased and formatted from this menu. Please note that all cards need to be formatted in
the ZMT4 Flex prior to recording.
Before formatting the card, the transmitter can optionally be renamed (see set up menu). When a transmitter
is named that name is included in the recorded file names. By naming the transmitter it makes it easier to
differentiate files from different recorders, so for example the card can be identified with the talents name, or
any other unique identifier. The card name menu is located at the end of the set up menu. The factory default
name is the transmitter’s serial number.
Partial Format
If the card’s FAT32 file structure gets corrupt while doing a file transfer, and the card is no longer recognized
by the transmitter or by ZaxConvert, a partial format can be done. The partial format rewrites the FAT32 file
structure and leaves the recorded audio untouched. To do a partial format from this menu press the DEC key
9 times “PARTIAL FORMAT” will then be displayed.
Playback Control
Recorded files can be played back from this page.
The top line displays the current mode of the recorder: REC, PLAY or STOP followed by the time code.
The bottom line contains the current segment number and the audio level.
Playing back from the transport page:
•Pressing the INC key while stopped will play the segment number that is displayed.
•Pressing the DEC key while playing back will stop the playback.
•Pressing the DEC key while stopped will jump back.
•Holding the INC key will jump ahead one segment.
•Holding the DEC key will jump back one segment.
•Pressing the INC key while in play mode will cause the playback to jump ahead, repeated quick presses will
cause playback to advance in larger increments.
PRESS UP KEY 5X:
TO ERASE CARD
STOP 09:18:05:02
SEG 001

Zaxcom ZMT4 Flex Record Menu
12
Time Left on Card
This menu will only appear if a card was inserted prior to booting up
This page displays the remaining record time left on the card as well as the time already recorded on the card.
Automatic Record after Boot up
Record on boot up allows the onboard recorder to automatically start recording after the ZMT4 Flex boots up.
•ON - The onboard recorder will automatically start to record after the ZMT4 Flex boots up.
•OFF - The onboard recorder will wait for a ZaxNet command or a manual record trigger to start recording.
Low Battery Stop Set
Low battery stop will set the amount of time, after a low battery warning occurs, the on-board recorder will
close the current file and stop recording.
This is to prevent possible file corruption if the unit constantly powers off and on due to a dead battery.
•NEVER STOP - The onboard recorder will not stop recording unless it is manually stopped by a key press, or
when it receives a stop command via ZaxNet, or if the battery dies.
•Any interval from 1 to 99 minutes - Once the battery indicator starts blink a low battery warning the
onboard recorder will continue to record for the time set here - then it will close the file and stop
recording.
TIME LEFT 20 H
TIME USED 4 H
RECORD ON BOOTUP
OFF
LOW BATT STOP:
NEVER STOP

Zaxcom ZMT4 Flex ZaxNet Menu
13
ZAXNET MENU
ZaxNet Mode
This menu sets the mode of the ZaxNet transceiver.
•OFF - The ZaxNet transceiver is disabled. The ZMT4 Flex will not receive ZaxNet commands or time code and
it will not send any ZaxNet audio. Please note if ZaxNet mode is set to OFF the several ZaxNet menu items
will not appear.
•RX - The ZaxNet transceiver will receive ZaxNet commands and time code.
This screen will display what ZaxNet data is being received by the ZMT4 Flex. Including total received
information packets, ZaxNet TC received and remote-control commands received. This information is used
for debugging purposes.
•TX - The ZaxNet transceiver will send ZaxNet confidence audio and time code. Please note that in ZHD48
mode the ZMT4 Flex will not be able to go into transmit mode.
ZaxNet Receive Frequency Set
This menu will only appear if ZaxNet is set to receive (RX) mode
The ZaxNet receive frequency is the frequency that the ZMT4 Flex will get its wireless time code and remote-
control commands on. This frequency will need to match the frequency of the corresponding ZaxNet
transmitter. The ZaxNet transmitter can be a QRX with QIFB, Nomad, TRX900CL or IFB100/200. The ZMT4 Flex
can also receive ZaxNet time code from another TRX / ZMT4 transmitter or a ZFR recorder that is transmitting
ZaxNet on this frequency. Please keep in mind that the range will be limited when receiving ZaxNet from a TRX
or ZFR.
When the ZMT4 Flex is receiving a valid ZaxNet signal the signal strength will be shown as well as signal
strength meter that runs vertically on the far-right side of the screen.
ZaxNet Transmit Frequency Set
This menu will only appear if ZaxNet is set to transmit (TX) mode
The ZaxNet transmit frequency is the frequency that the ZaxNet transmitter on the ZMT4 Flex will broadcast
time code and confidence audio on. Please note the ZaxNet transmitted audio is for quality control purposes
and the expected range will be less than 20 feet.
ZAXNET MODE: TX
RX FREQ : 2.403 RX
SIGNAL : 28
ZAXNET TX FREQ:
2.473

Zaxcom ZMT4 Flex ZaxNet Menu
14
Group Code Set
This menu is where the ZMT4 Flex is assigned to a group. The group code allows transmitters to be grouped
together so they can be controlled via ZaxNet without affecting others.
So, for example a ZMT4 Flex set to Group 1 will be controlled by a ZaxNet transmitter set to Group 1 and a
ZMT4 Flex assigned to group 2 will be controlled by a Group 2 ZaxNet transmitter. This is helpful if two or more
people on set are sending ZaxNet commands. Therefore, the different group codes allow each person to be
independent and not interfere with each other. Most users leave the group set to 1 on all their Zaxcom
products. Group codes can be set from 1 to 99.
Unit Code Set
This menu is where the ZMT4 Flex is assigned a unit code. The unit code is a unique number used to identify each
ZMT4 Flex within a particular group. This allows individual transmitters within the same group to be independently
controlled. Each transmitter should have a different unit code.
Unit codes can be assigned any number from 1 to 200.
ZaxNet Voting Enable
This menu will only appear if ZaxNet is set to receive (RX) mode
The purpose of voting is to allow the ZaxNet receiver in the ZMT4 Flex to choose, and switch to, the stronger
signal from two different ZaxNet transmitters. One purpose of this is if on a large set a second IFB transmitter
can be placed at a different location so the ZaxNet receiver in the ZMT4 Fex can choose the stronger signal.
Please note that the second ZaxNet transmitting frequency must be set 2MHz higher than the first ZaxNet
transmitter.
REMOTE CONTROL
GROUP CODE = 1
REMOTE CONTROL
UNIT CODE = 001
ZAXNET VOTING:
NORMAL (OFF)

Zaxcom ZMT4 Flex ZaxNet Menu
15
ZaxNet Receive Before Transmit Time
This menu adjusts the state of the ZaxNet transceiver. This also sets how long after boot-up up the ZMT4
Flex will search for ZaxNet time code before it begins transmitting its audio over ZaxNet for monitoring
purposes. This is so the ZMT4 Flex can lock to ZaxNet time code source before the unit will send confidence
audio over ZaxNet.
Receive only mode.
The ZaxNet transceiver will only receive ZaxNet and NOT go into
transmit mode. Therefore, no ZaxNet TC and/or audio will be
transmitted. This setting shuts off the ZaxNet transmitter.
Receive then Transmit mode.
After booting up the ZaxNet transceiver will search for a
ZaxNet signal for the selected time so it can receive and
lock time code before it begins to transmit TC and
confidence audio.
Transmit only mode.
The ZaxNet transceiver will only transmit ZaxNet TC and
audio and will NOT receive wireless TC or ZaxNet
commands. This setting shuts off the ZaxNet receiver.
RX TO TX TIME:
OFF (NORMAL RX)
ZAXNET RX TO TX:
0 SEC: TX ONLY
ZAXNET RX TO TX:
20 SEC

Zaxcom ZMT4 Flex ZaxNet Menu
16
IFB Receive Pulse Set
This menu will only appear if ZaxNet is set to go into transmit in the RX to TX Time menu.
This menu sets the interval that the ZaxNet transceiver will stop sending confidence audio and search for time
code.
When enabled the pulse setting tells the ZaxNet transceiver to leave ZaxNet transmit mode once every XXX
seconds and go into receive mode so it can re-jam its time code wirelessly via ZaxNet. This setting would be used
so the ZMT4 Flex could update its time code while monitoring audio via an ERX receiver. Please note when the
ZaxNet transceiver searches for ZaxNet it will temporally go out of transmit mode for approximately 1 second as
it searches for ZaxNet time code. The settings are NEVER or any interval between 5 and 999 seconds.
Record Beep Set
This menu will only appear if ZaxNet is set to transmit (TX) mode
When the record beep is set to ON, and the ZMT4 Flex is recording, the confidence audio sent to the ERX via
ZaxNet will have an audible beep, in variable intervals, giving conformation that the ZMT4 Flex is indeed
recording. The beeps will only be heard in the ERX and will not be recorded on the card, or be sent to the UHF
receiver. The intervals can be set between 2 to 18 seconds in 2 second increments.
The ZaxNet transceiver will stay in transmit mode and never go into
receive mode.
In this example the ZaxNet transceiver will go out of transmit mode
every 10 minutes. This setting would be used so the ZMT4 Flex
could update its time code while monitoring audio via an ERX
ZAXNET RX PULSE:
OFF
IFB RX PULSE
600 SECS
ZNET RECORD BEEP
OFF

Zaxcom ZMT4 Flex Audio Menu
17
AUDIO MENU
High Pass Filter
The high pass filter is turned on and adjusted from this menu.
The high pass filter range is 40Hz to 220Hz in 10Hz increments.
2K Notch Filter
The 2K notch filter is useful in removing digital RF interference that can be introduced into some microphones.
HIGH PASS FILTER:
90Hz
2K NOTCH FILTER
ON

Zaxcom ZMT4 Flex Audio Menu
18
Dynamics
The dynamics is a soft knee compressor that is located after the analog to digital converter which will limit
the dynamic range to prevent clipping during occurrences of loud audio. Dynamics is comprised of both a
compressor and an expander, which operate jointly. The compressor in the dynamics can set to mild or
extreme compression and features a soft knee for more transparent operation.
To enter the Dynamics Menu
Press the INC or DEC key - “PARMS” (parameters) will be displayed on the right.
To move to the next parameter, press the MENU key.
To exit this page, hold the MENU key for 1 second.
Dynamics Parameters
•Link L-R: OFF / ON: If using a stereo transmitter this links the left and right signal so if one side of the signal
needs compressing / expansion the other side will do the same to match.
•SPEED (Decay Speed) : SLOWEST / SLOW / NORMAL / FAST / FASTEST
Sets how gradual the signal level decreases after a signal reaches the threshold setting. This is typically set
to FAST.
•ATTACK (Attack Speed) : SLOWEST / SLOW / NORMAL / FAST / FASTEST
Sets the speed in how fast the gain is reduced once the signal exceeds the threshold setting. This is typically
set to FAST.
•CMP RATIO (Compressor Ratio):Valid range: 1.0: to 5.0:1, in 0.1 steps.
The amount of gain reduction is determined by the compressor ratio setting.
A compressor ratio for example of 2.0:1 means for every 1 dB above the compressor threshold the gain will
be reduced 2dB. A higher ratio setting makes the compressor more aggressive.
•CMP THRESH (Compressor Threshold): Valid range: 0 to –96dB, in 1dB steps.
This sets the level in which gain reduction occurs.
•CMP KNEE:(Compressor Soft Knee): Valid range: 0 to 20dB, In 1dB steps.
Sets the compressor's soft knee. A soft knee reduces “softens” the audible change from uncompressed to
compressed, this is useful especially for higher ratios where the changeover is more noticeable
•EXP RATIO (Expansion Ratio):Valid range: 1:1.00 to 1:4.00, In 0.01 steps
Sets the expansion ratio. For example a 1:2.0 expansion ratio means for every 1 dB below the expansion
threshold the gain will be reduced 2dB.
•EXP THRESH (Expansion Threshold):Valid range: 0 to –96dB, in 1dB steps.
Sets the threshold above which gain reduction occurs.
•REDUCE (Expander Gain Reduction):Valid range: 0 to –36dB, in 1dB steps.
This sets the limit on the amount of gain reduction caused by the expander.
•GAIN (Make-up Gain):Valid range: 0 to 30dB, In 1dB steps.
Gain is used to compensate for the gain reduction caused by the compressor. Because the compressor is
reducing the gain (or level) of the signal, the ability to add a fixed amount of make-up gain at the output is
provided so that an optimum level can be reached.
DYNAMICS

Zaxcom ZMT4 Flex Setup Menu
19
SETUP MENU
Test Tone
•
•
•
•
The ZMT4 Flex has an internal tone generator so the signal chain can be properly gain staged. From this menu
pressing the INC key will turn on the tone generator pressing the INC key will cycle trough the different tone
options (500Hz at -20, 1000Hz at -20 or 500Hz at full scale).
Standby Mode After Boot Up
This menu sets what power mode the ZMT4 Flex boots up to.
•NORMAL MODE - The transmitter will boot up normally.
•REMOTE STANDBY - The transmitter boots up in low power standby mode. The transmitter will be waiting
for a ZaxNet “WAKE” command to come up to full power.
Key Lock On Boot Up
This menu sets what happens to the keys on the face of the ZMT4 Flex after boot-up.
•LOCKED - After boot-up has completed, the transmitter will automatically go into lock mode and the keys
will be locked to prevent accidental changes to the settings.
•UNLOCKED - After boot-up the keys will remain unlocked. In unlocked mode the keys can still be locked
going into the lock screen in the main menu and wait 5 seconds.
To unlock the keys at any time - simultaneously press the MENU and INC key 5 times.
QRX / ERX Firmware Update
This page is used to update the firmware on a QRX or ERX receiver.
If the ZaxNet mode is set to OFF or receive (RX) this menu will allow for QRX firmware to be updated - if the
ZaxNet mode is set to transmit (TX) then this menu will allow for ERX to be updated.
For complete update instructions see the FIRMWARE section in the back of this manual.
STANDBY
B00T
MODE:
NORMAL MODE
KEY LOCK ON BOOT:
UNLOCKED
PRESS TO SEND
QRX PROG FILE
TEST TONE: ON
I I I

Zaxcom ZMT4 Flex Setup Menu
20
OLED Brightness Adjust
This setting adjusts the brightness of the OLED display. The brightness setting is from 0 to 3 with 3 being the
brightness.
OLED Display Dim
This setting adjusts how long after the last key press the display will dim. The dim time can be set from 1 to 60
seconds in 1 second intervals.
Information Page
This page displays the current firmware version, the serial number, the DSP version, and the option code.
Hide Encryption Menu
This setting will hide the encryption menu. A hidden encryption menu allows for quicker navigation and
prevents accidental changes.
•HIDDEN - The encryption menu doesn’t appear when cycling through the menu settings.
•DISPLAYED - The encryption menu will appear.
ENCRYPTION MENU:
DISPLAYED
- - - INFO - - -
FIRMWARE V2-78
SN: 1234 DSP:1B (ZHD)
OPT = 07 Z-SPORTS-S
OLED BRIGHTNESS:
3
DISPLAY DIM:
OFF (NORMAL)