Author: Ken Wells - NM9P Date: April 13, 2023
Adjusting your Microphone Settings for best TX Audio:
Here are some suggestions for adjusting your existing Microphone or a new microphone to get the top quality Transmit Audio that you desire from your FlexRadio.
- Select the proper Mic Profile as a "Starting Point"
The first step, after selecting and connecting a microphone to your radio, Maestro, or computer is to select a Mic Profile for that mic or a mic that is similar to it. Use this as a "starting point" for creating a Mic Profile for this Microphone.
- Create a new Mic Profile for your experimentations and give it a new name.
Click on "Profiles > Create Mic Profile" and enter a new name for the mic profile, such as "PR22_RAG" (Which is the name of my "Rag Chew" Profile for my PR22 Mic)
Hit the "CREATE" button to create the profile and set it as the "active" Mic Profile for the slice and mode you are using.
- Select the proper Mic Input:
In the "PHNE" Sub-Panel of the "Radio Controls" panel (the right-hand panel in SmartSDR) look to the Mic Selection Pull-down menu and select the proper Mic Input:
(The list will vary, depending upon the model of radio)
MIC - for the Front Panel Mic Connector on 6300/6500/6700 or the rear panel 1/8 inch mic connector on a 6400 or 6600.
BAL - For the Balanced Mic connector on a 6600, 6500, or 6700.
(the 1/4 inch on all three, or XLR on 6500/6700)
LINE - Same as BAL, but disables the +20 Mic Boost.
(This is often used if you are using an external MIXER or Mic Preamp.)
ACC - If you are feeding Line Level audio into the rear panel ACC connector
PC - If you are using a mic connected to your computer's sound card input,
or a USB mic connected to the computer.
(If you are using a Maestro, see below for additional Mic Input options.)
- Set the proper BIAS and +20 Mic Boost settings for the mic you are using.
These settings are found in the "Settings > Radio Setup > Phone/CW" tab.
If you are using an Electret Mic, turn the BIAS ON (BLUE)
If you are using a Dynamic Mic, turn the BIAS OFF
+20 dB (Mic Boost):
This adds 20 dB of additional Mic gain for use with microphones that have lower output.
It is usually not needed with most electret mics,
It is often needed for use with "professional" studio or vocal mics.
If there is not enough audio out of the mic, turn it on. (BLUE)
Also: Enable the "Enable LEVEL Meter during Receive" option, which will allow you to set your Mic Levels on the LEVEL meter while in receive mode without needing to hit the PTT.
- Set the desired Transmit Bandwidth - (Low-Cut and High-Cut)
This sets the TX audio frequency cut-offs and your ultimate TX Bandwidth.
For a "Rag-Chew" audio, you may want to have "Low-Cut" at 50 or 100 Hz which determines the "low-end" cut-off for your audio.
For a DXing or Contesting audio, you may want to set the Low-Cut up to 200 or 300 Hz which will allow more power to go to your higher frequencies and not be wasted on the "bass notes."
For a "Rag-Chew" audio, you may want to have "High-Cut" between 2700 and 3100 Hz.
This determines the "High-end" cut-off for your audio. (and your ultimate high-end TX bandwidth)
For a DXing or Contesting audio, you may want to set the High-Cut to between 2400 and 2900 Hz, depending upon how wide you want your transmit signal to be.
- Set the proper PEAK Audio level on the Level Meter.
Adjust the Mic Gain (see the slider in the Yellow Box) for the proper PEAK Audio Level.
NOTE: The LEVEL meter has a "Dual Indicator"
The Solid Bar is the AVERAGE audio level reading.
The little line that dances ahead of the solid bar is the PEAK Audio Level Indicator.
THIS is the indicator to use when adjusting your mic.
It should peak between the -10 and -5 on the LEVEL meter.
NOTE: If you are setting many of the TX EQ Settings above the "0" mark, you may need to reduce your Mic Gain a little to compensate for the additional gain introduced by the TX Equalizer.
- Adjust TX EQ settings carefully to "fine-tune" the audio you wish.
Be certain that the TX Equalizer is selected (TX Button is BLUE)
and that it is turned ON (Button is Blue)
The sliders can change both the TX Equalizer and the RX Equalizer. Both are enabled individually, and you must select RX or TX in order to make changes to their respective EQ settings
Here is an example of someone's TX EQ Settings. (this is only an example, not a recommendation)
- Set your PROC (Processor) to the level you wish:
We recommend that you always use PROC at least at NORM.
Use NORM for a "Normal, or Rag-Chew profile.
Use DX or DX+ for some added "talk power" for DXing, Contesting, or Weak Signal work.
(See the links below for a great video that explains our Processor)
- Set any DEXP (Downward Expander) that you need:
(This is only available on microphones connected directly to the radio)
The DEXP Control is located in the PHNE Sub-Panel of the Radio Controls Panel
The DEXP Level slider is just to the right of the button
The Downward Expander reduces the microphone input gain during the quiet periods between spoken words, eliminating extraneous background noise. This improves the apparent signal to noise ratio of your transmitted audio by “soft gating” ambient room noise between words.
To adjust the Downward Expander, enable DEXP and move the DEXP Threshold slider to 0.
While transmitting and listening with MON (Monitor) without speaking, adjust the DEXP Threshold until you can no longer hear the background or ambient noise at your operating position.
In most cases a DEXP threshold level of 50-70 should be sufficient.
NOTE: Setting DEXP too high can result in unexpected clipping and distortion of your transmit audio.
- Using VOX (Voice Operated Relay)
AFTER you have completed all of the adjustments above, you can set up VOX for "hands-free" operation.
Turn on the VOC using the VOX Button in the PHNE tab of the radio Controls Panel.
If the button is BLUE, the VOX is ON.
Use the VOX gain slider to the right of the VOX Button to set the needed VOX Gain.
Use only enough to assure stable activation of the VOX for transmitting. If the gain is too high, random noises in the shack will trip the transmitter and send unnecessary QRM on the band.
Use the VOX Delay slider to determine how long to wait after you have finished speaking before the radio returns to receive mode. I suggest starting with 15-30. Use enough so that the VOX only trips between phrases, not between words or syllables. Especially when using an amplifier.
(The actual delay time in ms is the slider setting x 4)
Cautions for using VOX:
VOX is much more effective when using headphones, because sound from the main speakers can trip the VOX relays.
Don't try to use VOX if your habit is to use a desk mike at "arm's length" and shout into the mic!
When you leave the shack, disable VOX so that random household noises, conversations, TV and Music will not accidentally be transmitted over the air, resulting in embarrassment or worse.
- Monitoring your audio while making adjustments:
The MON (Monitor) function lets you hear your voice while you transmit, but it does NOT give you an exact representation of what you sound like on the air. This is because the MON is tapped BEFORE the Filtering, Processing, and TX EQ are applied.
If you wish to monitor your actual audio quality, use the "Quick Record and Playback" function.
Press the little red dot on the Slice Flag to start recording.
It will slowly flash while you are recording your transmission. Press it again to stop recording.
Then press the Green Triangle to play back your recorded voice.
This will play back your Transmit audio as it would be heard on a radio that is using the same receive filters and settings that your slice is currently using.
Alternately, you can use the Full-Duplex technique detailed in the videos in the links below.
- IF you wish to create additional Mic Profiles based upon this one for additional purposes:
(for example to make a DX or Contesting Profile based upon this one)
"Create" a new profile while this one is active, then name it something else, such as "My_Mic_DX" instead of "My_Mic_Rag-Chew"
Then make all of your adjustments on the new mic profile.
NOTE: Any changes you make to the settings in the above steps are AUTOMATICALLY SAVED to the profile that is "active" in the Mic Profile pull-down on the Radio Controls panel.
Where to find these settings on the M-Model Front Panel or Maestro?
Rather than repeat all of these instructions for the Maestro / M-Model Front Panel. This paper will simply point the reader to the equivalent controls and where to find them.
Open the TX MENU by pressing on the Mic Gain/CW Speed knob that is above the VFO B knob and you will find the following controls:
- Mic Profile pull-down: on the bottom left of the screen
- Mic input Selection pull-down: on the left-hand side of the screen.
M-Mic1 - the RJ45 Connector on the back of the Maestro
M-Mic2 - the 1/8 inch TRS on the Back of the Maestro
M-LINE - The Line-In 1/8 inch jack on the Back of the Maestro.
R-MIC - The Front Panel or 1/8 inch Mic Jack on the Flex Radio
R-BAL - The Balanced (XLR or 1/4 inch TRS) connector on the back of 6500/ 6600. or 6700 Radios.
R-LINE - Same as the BAL selection, but the +20 dB Mic Boost is disabled
R-ACC - The Line-In pin on the ACC Jack on the back of the radio
- TX Filter (Bandwidth) settings: Low-Cut and High-Cut are on the right-hand side of the TX MENU
- PROC (Processor) controls are on the upper left of the TX MENU
- DEXP (Downward Expander) controls are near the bottom-center of the TX MENU.
- VOX (Voice Operated Relay) controls are in the top-center of the TX Menu
Other controls for Transmit Audio are found in these locations:
Mic Gain: use the knob that is above the VFO B knob
BIAS, +20 dB Mic Boost, and "Enable Level Meter During Receive" are in "MENU > Phone/CW"
NOTE: The Maestro has settings for BIAS and +20 dB for BOTH the Maestro Mic Inputs and the Radio Mic Inputs.
TX EQ: "MENU > Transmit" -- scroll to the bottom of the screen
Here are some additional helpful video Tutorials and documents that may be helpful:
A good tutorial video produced by Mike Walker, VA3MW:
Microphone Connections and Setup - YouTube
A great video about our Processor and CESSB by the guy who created it!
A great article about EQ principles, and how the different EQ sliders affect your sound:
Rules for EQing Voice for Optimal Phone Operation – FlexRadio
Here are three tutorial videos for TX Audio Profiles that go into greater depth:
A Tour of Transmit Profiles on the Flex-6000 Series - YouTube
Adjusting the 6000 for the Standard Hand Mike, or any new mike - YouTube
Full Duplex Monitoring on Flex 6000 Series - YouTube
The last three are a little dated (see the comments) especially regarding how to save them, and how to adjust the Peak LEVEL meter. (we now recommend setting no more than -10 to -5 on the Peak level meter reading.)