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How's My Audio?

Terry AB2UE (KC2LZD) on June 8, 2017
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How's my audio? The Yaesu FTDX 1200 TX eq and processor setup guide

"How's my audio" is commonly heard throughout the HF Bands these days. Options abound as how to tweak transmit audio to a precise sound. Investing in outboard gear has become common place.

Voices are like snowflakes, no two are alike. So, how can you Eq your audio based on someone else's settings?

My settings are as follows; mic gain @ 25, processor is "on" @ 25. Transmit bandwidth is set at 100 to 2900 Hz so it doesn't cutoff the Eq frequencies. Parametric Eq frequency/level/bandwidth settings are; 200/9/5, 1500/5/5, 2700/5/5.

Now, I will explain how I arrived at these settings which are particular to my voice. Yours will differ.

Start by downloading www.audacityteam.org , a free audio software program. Record a track of your voice.
Save the track & select "analyze". Then, 'plot the spectrum. You will see a frequency analysis of your voice using your mic.

In my case I used a modified Yamaha CM500 electret condenser mic with a frequency response of 100 Hz to 20 kHz.
As is, the CM500 output is 150 mV (batteries installed). The mic audio level was too hot (high) for my radio. A 10:1 voltage divider was added. This reduced the audio level to 15 mV. The voltage divider was made up of a 1 k Ohm resistor in series with the audio (+) line and a 100 Ohm shunt resistor. The resistors can be added inside of the battery box for a clean installation. Already in the battery box is a load resistor & 1 uF capacitor.
The headset can be plugged directly into your PC without the battery box. An adapter was made to connect the headset to the radio.

Back to Audacity. Notice your voice frequency profile where the dB levels go up & down within your vocal response. Save the file.

Back to the radio. Connect your rig to dummy load with a watt meter. Set Eq off, processor on, mode = SSB, mic = 20, processor = 20. Transmit bandwidth set to "TTBF". RF power level = 100 W.
Connect an audio signal generator to mic input. Set audio frequency to 1 kHz. with the audio signal level adjusted to get 100 W RF with no ALC deflection. Then select multiple frequencies between 10 and 5000 Hz to get enough data to plot the filter shape on graph paper [frequency verses power output]. Key the rig just long enough to take a reading. Remember, you're at 100% duty cycle. Convert power to dB.

Surprised ? That 4 kHz transmit bandwidth you read about is -9 dB at the high & low frequency limits.
The Yaesu owners manual on page 134 says: " SSB audio response not more than -6 dB from 300-2700 Hz".

Compare your radio audio plot to the Audacity spectrum plot. This will determine where to cut or boost frequencies with the Eq turned on to obtain an overall full spectrum audio within the limitations of the radio transmit bandwidth & your voice/mic frequency response.
In my case I needed +9 dB @200 Hz to get the power up to the same level recorded @1 kHz.

Mic gain and processor level settings are identical for a reason. It was found through testing that when both are set at the same levels, the radio power output is 2.5 times greater with the processor "on" verses the processor "off". This relationship repeats for each identical setting[15/15, 20/20 , 30/30, etc...

While speaking into the mic make sure the gain setting does not exceed the ALC limit. Compression level, it turns out, is no greater than 5-10 dB.

There are certainly many other methods of setting up the mic and processor, but I learned a lot by doing it this way. I would like to hear from anyone that has duplicated this process.

How's my audio ? I've been given unsolicited, "great audio" reports as a result of using this audio adjustment method.

How about you?

Member Comments:
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How's My Audio? Reply
by N8CMQ on June 8, 2017 Mail this to a friend!
And then someone tells you, 'You have RF on your audio...', and you start checking everything over again!
 
RE: How's My Audio? Reply
by K6AER on June 9, 2017 Mail this to a friend!
The only sure way of see your over the air audio response is with a receiver that has an accurate spectrum analyzer display. Flex and Apache units do very well or a real spectrum analyzer. Shaping your audio and hoping the radio has a flat response is wishful thinking. Over modulation will increase the radios IMD (bandwith) and that can only be seen with outboard spectral analysis or careful signal monitoring on the other end.

Each voice is different and trying to increase the transmitted highs when there is none can introduce acoustic shack noise into the audio.

When your signal is above S9 the ham can walk you through your settings with ease.
 
How's My Audio? Reply
by VE3TMT on June 9, 2017 Mail this to a friend!
Jeez that's sounds like an awful lot of work.

When I owned my FTDX-1200 I ran a Koss SB40 dynamic headset on it and got many unsolicited compliments on the audio.

I know run the same headset on my PROIII with the same results.

I used only the TX monitor function of the radio. It ain't rocket science.
 
How's My Audio? Reply
by K9CTB on June 9, 2017 Mail this to a friend!
Great piece here! I personally LOVE audacity for QC and monitoring purposes. IMHO, it is a good idea for hams to have some sort of quality monitoring setup as part of their shack. I have used a receiver with attenuator bank and audacity for a few years now. You simply can't rely on your fellow ham at the other end of a QSO to diagnose audio quality problems. There are too many external path things which can botch up your signal, and those issues can't be corrected on your end. If you can tap into your transmit audio - before the rig - on one track and then your demodulated signal on another, you can tell quickly by listening about any adjustments you should make. For extra assurance as the article states, you can also view the spectrum display or the waveform and compare. For digital signals, Audacity works the same way. You can make a recording of audio at any stage in the chain ... and replay it to see if you can demodulate it. Audacity is so much better than a tape recorder!

73,
K9CTB
 
How's My Audio? Reply
by AF4RK on June 10, 2017 Mail this to a friend!
I do want to congratulate the author on achieving the results he desired. However, the process became a hobby in itself. I use Audacity for making contest recordings. This is too much work for a headset! You could also buy a Rugged Air RA 200 aircraft headset for not much more than the CM500. I use the RA200 with an Icom 7300 and get great results with no "dog house" box. A few tweaks in the Icom menu is all that is needed to adjust bass and treble to YOUR taste. There is no "perfect" setting, it's all subjective. Whoever is listening is going to add their interpretation of "good" sound. Rag chewers HATE a contest sound and a rag chewer sound doesn't work in a pileup. All of my Icom friends got the same headset when they tried mine! there's an adapter that plugs right into the radio. I did have to make an aircraft mic to 1/8 stereo cable. The results have been gratifying for DX pileups and contesting.
73
AF4RK
 
RE: How's My Audio? Reply
by KC7MF on June 10, 2017 Mail this to a friend!
Nice article. I think that many hams do not realize how versatile modern transceivers are in this regard.

I act as net control for a fairly busy net a couple of times a week so I hear a lot of different audio presentations. There is no doubt that what we often refer to as "DX audio" offers some advantages to being heard and "FM audio" is much easier on the ears. That said.

It seems to me the key is to play to the strengths of your station. If you run a lot of power and/or have an antenna that hands you considerable gain you can afford to have more pleasing but less penetrating audio. If you run 100 watts into a dipole you might want to consider giving yourself the advantage of that more penetrating audio to increase your chances of making the contact.

As to others helping you on the air... It is useful to tell the other station what you are trying to accomplish. Rather than "how's my audio" ask them to judge the signal for busting pile ups or pleasant conversation. Otherwise it would be natural for the helpful station to decide on his/her own standards. If your goal is to bust pile-ups or chase weaker DX, be sure to ask some of those stations to help you. When you are (real) 5-9 the natural tendency for the station helping you is to make you sound like the announcer on a television program. Pleasant but subdued. This may not serve your goals.

73
 
How's My Audio? Reply
by WD9IDV on June 10, 2017 Mail this to a friend!
Can you hear me now?
 
How's My Audio? Reply
by WD9IDV on June 10, 2017 Mail this to a friend!

Can you hear me now?
 
RE: How's My Audio? Reply
by N3HKN on June 11, 2017 Mail this to a friend!
Another checkbook issue. Transceivers are well over $1000 as the normal. Now to get acceptable audio spend an almost equal amount of money. I agree that this is a separate hobby (cash outlay) and really is not needed to communicate. A 100ft tower, a large beam, a 1500w amplifier and a top-of-the-line transceiver, then add more equipment so you sound great on the other end? That sounds like a broadcast station.
 
How's My Audio? Reply
by LNXAUTHOR on June 11, 2017 Mail this to a friend!
not surprising - anyone remember the 2001 post 'I hate 75 Meters'?:

http://www.eham.net/articles/2189

ROFLMAO!
 
How's My Audio? Reply
by KE4ZHN on June 13, 2017 Mail this to a friend!
I set my 1200 up using another rigs receiver with a pair of headphones on a dummy load. I use an MD 100 desk mike. No studio gear at all. Only took a few minutes to get the EQ set for my voice. Once you understand how a parametric EQ works it's pretty easy. Also this confuses some, but there are two separate EQ's in this rig. One for processor off and one for processor on. This allows you to set your processed audio up for DX if you wish without disturbing your rag chew settings.
 
RE: How's My Audio? Reply
by KC2LZD on June 18, 2017 Mail this to a friend!
You're right, 'it ain't rocket science' & i use the transmit monitor to listen to myself as well.
Injecting audio signals into the mic input is an alignment step for Kenwood hybrid radios[TS-830] for SSB frequency response, ALC & speech processor adjustment.
I used a similar technique to plot filter shape in FTDX 1200.
Thanks for your response, 73 Terry
 
RE: How's My Audio? Reply
by GM1FLQ on June 19, 2017 Mail this to a friend!
"That sounds like a broadcast station."

Awwww, don't you go spoiling it for them now......let the kiddies keep on pretending.
 
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