Poor/Bad Transmit Audio Flex-6300

vincentjlawrence

Very poor TX audio with Flex 6300 as reported by numerous people. I would like to return the radio for examination. What is ECO 75-1006?
Running SmartSDR 1.3.8

Seems like the lower voice frequency octave overloads the internal TX audio circuits.

Duane_AC5AA

Have you tried going to the TX audio equalizer and rolling off the lower frequencies?  Some of the canned profiles have a lot more bass in them than is usually used in ham radio communication.

Jim Gilliam

What do you mean by a low frequency octive? 100-200 200-300 300-400 400-800?

Tim - W4TME

If you do not make any progress with the suggestions provided here on the Community, I recommend that you submit a support ticket via our HelpDesk (http://helpdesk.flexradio.com) so we can investigate further.  For details on how to submit a HelpDesk support ticket, please refer to the following URL: http://helpdesk.flexradio.com/hc/en-us/articles/202118688-How-to-Submit-a-Request-for-Technical-Supp...   Once the support ticket is submitted, a support engineer will be in contact so we can work on the issue.  Make sure to include your radio's serial number.

Dave - W6OVP

This is what I did. Made all the difference. YMMV:

1) Got rid of the factory mike. I chose the Heil HMM Handheld since I don't like headsets.
2) Set my transmit audio to:  -4  -8  -4  +4  +8  +9  +6  +3.

Duane_AC5AA

Start with 200 Hz and below, just to see if this helps any.  If it does, just go from there.  It helps if you have a separate receiver to listen to yourself. 

Rhett Aultman

I got *lots* of people saying "there is a lot of bass in your audio" when I first set up my 6300.  Some liked it, but I was missing a lot of QSOs and finally someone, on a QSO, worked with me one night.  I basically ended cutting my bass sliders down to nearly the bottom and got a very clean audio report after that.

vincentjlawrence

Yes, I sidelined of the Flex provided microphone and purchased a Hiel gold elite dual element mic. Also, using the equalizer I took out all the low frequencies (100 - 500) and boosted the mid range frequencies. However, the audio still is marginal - looks like there is a very poor basic frequency response in the transmit circuit of the 6300. One should not have to set a curve like the one suggested here and elsewhere. This is NOT necessary with my ICOM 7700 and 7600 756 PROIII.

Here are my TX equalizer settings: 63 HZ  at minimum e.g. -10 DB, 125 HZ -10, 250 HZ - 5, 500 HZ -2, 1000 HZ  + 8 DB, 2K + 10, 4k +8..  Also, I purchased an audio generator kit and will be running its output through the flex and will produce a graph using my oscilloscope and RF digital outputs from 50 cycles up to 3 KHz. That project is on-hold until after tax season. But I am reasonably certain that there is a design or production problem in the TX audio circuit.

Thanks for all that replied.

Tim - W4TME

"However, the audio still is marginal - looks like there is a very poor basic frequency response in the transmit circuit of the 6300. One should not have to set a curve like the one suggested here and elsewhere. This is NOT necessary with my ICOM 7700 and 7600 756 PROIII."

This is because those radios have pre-emphasized audio preamps that cut lows and boot highs.  The audio input response on the FLEX-6000 is flat.  All pro audio equipment that has a flat response will need some sort of EQ "S curve" to flatten out the voice response of a typical human male.

KY6LA_Howard

@Tim

Flex is **** if you do and **** if you don't

Since Flex has instituted a Flat Audio response curve as found in the Professional Grade Audio Equipment you are **** because you do not conform to the NON FLEXIBLE pre-emphasized audio preamps that cut lows and boot highs of many Legacy radios which is preferred by many appliance operators even though the Legacy settings may make some people (like me) sound terrible.

But if you had instituted the pre-emphasized audio preamps that cut lows and boot highs of the Legacy Radios you would be **** by the ESSB/AM guys who use the external audio equipment such as W2IHY to correct the audio deficiencies of the legacy radios.

Of course, Flex has provided everyone with an 8 octave equalizer so that they could adjust their audio to compensate for their microphone characteristics which virtually eliminates the need for external audio boxes...

But that might just require some people to read the manuals, perhaps listen to their audio and make some adjustments. 

You just can't satisfy everyone....


FWIW... My Flex Radios Always receive much better audio quality reports ("FM Broadcast Quality" from NA6L) on SSB than any of the K-3, IC-7800, IC-7700, IC-756Pro 3.... that I have used...  even when remoting through a $26 Logitech Bluetooth Headset... 

George KF2T

Just a reminder that Transmit Profiles are delivered with built-in EQ settings for several popular microphones, including the Flex hand mic, and Heil's offerings. I applied the settings for my PR-40 and have had nothing but excellent audio reports.

The Transmit profiles are easily accessed in the TX pane. You may wish to have the EQ pane open to see what the differences are.

Good luck!

Ken - NM9P

I prefer the flat response.  I have learned how to use the EQ and have gotten many, many compliments on my audio.  Including some from Bob Heil, K9EID.
===
Howard, What EQ settings are you using with the Logitech?  Mine just arrived today from Amazon, ($32.95) but the Bluetooth dongle won't get here for a few more days.  I want to be ready for 1.4 when it arrives.

Ken - NM9P

Vincent,

The TX EQ settings you are using should be a farily good starting point for that mike.  

Just a few diagnostic questions...

Are you sure you have the TX EQ turned ON?
  (Sounds like a dumb question, but I have seen it before when someone spent a long time adjusting the EQ with not much result and then I... I mean he...noticed that the TX EQ has not turned ON!)

Are you using the wide band mic element on it?

Where do you have the TX filter Low and High frequency limits?

What processor setting are you using?

Are you making sure that you are keeping the Mike level meter below the "0 dB" red zone at all times?

Also, double check the grounding lines on the mike cable.  Some of them have what is called a "pin 1 problem" or another wiring problem that creates a ground loop by grounding the shield and the low side of the audio line together.

Ken - NM9P

KY6LA_Howard

Here is the EQ I use with my Logitech Headset

Seems to get "FM Broadcast Quailty" Reports
YMMV

Jay Nation

Before you can like "flat response" you have to have tried it. They crank everything to max, or all the way to the right and think that means "all there is" it just won't go any higher. Once you've tried all there is, why try anything else? If they'd only try all knobs to the left, we'd like their audio. Ah, silence. no NR required. CQ wonderful, QRZ. RST is 599, and for once it's lovely don't change a thing.

73, Jay - NO5J  

Ken - NM9P

Non sequitur.

Rhett Aultman

Yeah, that was poetic, but weird.

vincentjlawrence

Again thanks for all the replies. If you read all the replies to my post, one of the common threads on the use of the equalizer is to create a bell shape curve with the emphasis on the 1k - 2k Hz areas and  greatly reduced gain at low and high frequencies outside of the normal voice communications range. Seems most people are using maximum gain in the 1k to 2K range. Don't you think this is strange? The settings mentioned are about the same equalizer settings that I have settled on. But I am still not satisfied with the response since the equalizer does not allow further increased gain in the mid to high voice frequencies.  Also, since many of the microphones cited by those responding to my post generally have a fairly flat frequency response (including the ones that I used: Heil (with 2 elements -switched to the limited frequency element), FLex and Yaseu), I suspect that the Flex 6300 equalizer or basic audio to RF circuit has a response which is directly opposite to the curves we all use. Again, I will emphasize that all other radios I have or had never required the extreme audio emphasis required by the Flex 6300.

I would like to thank Flex for sending me the RMA documents for my radio. I will be returning the radio to them and requesting that they run a diagnostic of the entire audio system by applying various audio frequencies from 50 Hz up to 3k Hz (perhaps in 50 Hz steps) and see how the RF output varies with a constant amplitude audio input. I ask the test be done with both the equalizer out of the circuit and in the circuit but set at flat gain through the entire frequency range. I look forward to seeing a plot of constant audio input amplitude over the voice frequencies vs power output.

Perhaps their ECO 75-1006 will have some influence on the problem.

Regards and thanks again.

Vince - N0UA

 

John n0snx

I have been playing radio for over 25 years and have been a Flex user for the last 6 years...I am also am somewhat of an audiophile.  Contrary to popular opinion, A mic that works good on some radios might not work good on ALL radios!!! And the same is true that a mic that works good with some voice types may not work for other voice types... They all might be great under certain conditions but not under other conditions..... I constantly see postings here stating (well it worked with my other radio... There has to be something wrong with this radio.)  When you are using a radio that has an EQ available it takes time to find that SWEET SPOT. you can't just use settings that someone else uses because it's their voice not yours. Thru all the radios I have used I have never found one radio that had an audio issue cause by something inside the radio, It has always been an issue from the mic plug out.  Before insisting your radio is broke, take the time needed to find the right combination that works for you...Believe me... it can get a bit frustrating sometimes... BUT DARE TO PERSEVERE!   There are MANY mic manufacturers besides brand X or brand Y..... You just have to find what works for you. Whether it is a $14.00 Transcontinental from amazon or $3200.00 Nuemann U87i from Sweetwater. Somewhere there Is a mic that work for your voice.

Dave - W6OVP

The problem with the excuse that "ours is better since it has so much flexibility" is that there is a very long precedent of quality transceivers being delivered to preform beautify literally "out of the box", by other manufacturers. No adjustments required. Kenwoods quality "out of the box" audio with factory mikes goes back half a century and is legendary. I recently added a new 590S, and plug and play from sealed box to first rave audio report was only a handful of minutes. NO TWEAKING was required. Get the same reports from a stock FT-857D, and a FT-817ND, and a KX-3. It is no big deal to get quality audio out of the box!

In broadcasting we worried about High Fidelty and all that. But this is Communications. Listeners are not in shock if they don't hear our mellifluous tones as our dog and cat hear them. They will probably never meet us anyway. This is about COMMUNICATION. This fretting about "but our voices are different" is just so much hokum.

This insanity about "flat response" on Ham Radio is a side track IMHO; one which is proving a very expensive diversion to the FLEX reputation (and dare I suggest to the bottom line?)

I see no reason why FLEX products cannot work as well as others, as the DEFAULT, right out of the box, with a factory mike. Then let the tweakers take it from there if they wish; instead of the other way around.

-Dave  W6OVP


.

Ken - NM9P

One of the reasons for the "Flat" audio response is that it also facilitates the digital modes more easily.  One problem with many standard rigs of other brands is that the audio response, being designed for speech, is not flat for the digital modes and is problematic.  

On the FLEX, the passband is completely flat from about 0-10,000 Hz if need be, and in digital modes the TX and RX EQ are taken out of the line to prevent alteration.  

For phone, the 6000 will work fine, "Out of the box" if one takes care to read the instructions and load the proper default profile to match the mike in use.  It is a simple matter to make additional tweaks after that, far easier than any of the other modern rigs where one must go several levels down into the menu system, define different bands for the parametric EQ, including frequency, gain and bandwidth, and then define them again for use with the processor ON.  

It is much, much easier to do it on the 6000 series - just select your Hi/Lo cut freuencies from the TX tab, then go to the EQ and move the sliders.  Then save the TX profile.  Do it again with different bandwidths or emphasis and processing setting for DX mode, and you are in like Flynn!

The panadapter gives you an excellent tool to visualize your frequency response (too much bass, not enough treble, too much midrange, etc. if you need some extra help.)   

I much prefer the ability to tailor my SSB audio response the way I want it, starting from a flat response, than trying to figure out what in the world the manufacturer did to the audio input and trying to correct or over-correct for it.

KY6LA_Howard

@Dave W6OVP We run "ShootOut". Tests 6700 vs K3, KX-3, IC-7800 ( we have a couple of Kenwoods and Yaesu's too but rarely use them) at the NX6T Contest Station several times a year ...I have reported on a few in this community. While we have some voiciferous arguments as to which is the best receiver under contest conditions, there is absolutely no doubt that the 6700 not only has the best SSB audio but also consistently receives by far the best audio signal reports NO MATTER WHICH MICROPHONE we use. Perhaps the best feature of a true flat repose audio chain is that I can use the built in Flex equalizer to perfect my audio so it does not matter if I use my$26 Logitech Bluetooth Headest when remoting, my $150 Heil Goldline XLR or my $350 RadioSport I still receive "FM Broadcast Quality" audio reports. Yes it took me about 10 minutes on the air with local friends to perfect each mike but easily worth it. By contrast when We tried Legacy Radios with their so called "Communicatios" response audio, while we get decent reports using a Heil PR781, we never could get as good audio reports with the wide variety of microphones we had unless we used an external audio equalizer box like the. W2IHY. Even then some mikes never could be optimized. The external audio equalizer was not necessary with the 6700. When we "punched up" the audio for contesting and DXing, again the. 6700 easily wins the "punchiest" yet most "understandable" audio. While I have a big antenna and big amp at my home station I usually am the first call that DX responds to in pileups. I regularly get questions as to what radio or mike I am using because my signal sounds "so strong yet clear" the compression on the 6700 is superb. What ultimately matters is on air performance and not silly things like "perform beautifully out of the box" when in fact in comparative tests, "beautifully" is pretty average with most microphones and terrible with many others.

K2CM

Did someone suggest checking for RF feedback?

Jim Gilliam

I have mentioned this before and will again. There is a program out there that runs circles around the IHY box. It's called Romac. It is a 10 band equalizer and have used it with legacy radios like my 7800 using the Heil line. Using a good USB electret microphone, I have my 7800 sounding every bit as good as my 6500. That, however, does not take away from the 6500 which I prefer. Also Romac has a reverb feature. Adding a little reverb enhances the communications quality of the audio.

Jim, K6QE

W9OY

I'm running a 6300 with a Electro Voice RE-320 mic I bought off EBAY for $200.  This mic is a  version of the standard professional broadcast mic the RE-20 which is used in every friggin recording studio in the world.  That means I started with a true pro quality mic designed to reproduce exceptional articulation.  That is what broadcasters/musicians/voice over artists sell, exceptional articulation.  (POINT NUMBER 1, if you want good audio don't buy a **** communications quality mic no matter if it's gold or platinum or looks like a lollipop.)  I run the mic into the front jack of the radio, using a cable I purchased from Heil.  I tried other cables and had RFI, after installing the Heil cable, RFI gone!  I hated paying like $40 for a friggin cable but that got the job done for me.

EQ is not necessary for this mic.  EQ is useful only in so far as you want to enhance certain qualities of the audio spectrum (i.e. you want to play with the buttons).  This mic run flat with no EQ will modulate the radio with excellently articulated pro quality audio.  You can add EQ if you like but that is for your artistic flair, that is YOU trying to personalize the quality of the audio based on YOUR perception.  It is not at all required if you start out with a true pro audio mic.

Flex radios have the ability to run very deeply into the bass register as well far into the treble registers.  The possible bandwidth is 0-10,000 hz.  Again this is your choice.  I run my radio with the low cut at 300hz and the high cut at 3050hz.  I have heard many Flex's that to me sound pretty bassy but I think that is because of the way the radio is adjusted.  I think because one can adjust the radio like this many do using the notion "if I don't use the controls I might miss some advantage"  There is no advantage to sounding too bassy but that is your choice.  How you want to sound is "just right".  It's the articulation that slices pileups and contests, and this radio gives astounding articulation if you use the right mic, as Howard says.

The Flex has the best speech processor in the business.  It basically adjusts the RF envelope to bring the average talk power up by 2.4 dB with out adding any distortion to the speech characteristic.  2.4 dB increase in average talk power is basically like doubling your power.  You best make sure the transformer in your amp is capable of handling the increased duty cycle of this radios waveform.  In addition the radio has downward expansion which improves the dynamic range and adds color back into the audio.  Flex includes the hand mic so you have a known starting place with a known standard mic.  You don't need to "send your radio back" if you start with that mic and can make your radio work with good clean RF free audio.  If you can't make your radio work with that mic then you likely need to clean up the RFI your amp/antenna is generating.  I had to clean up the mic cord at my station to eliminate the RFI.  I knew this was the case because when I plugged in the Flex mic the radio worked fine.  

How does it work?  With this mic and this cable and NO OTHER external or third party equipment or software, my audio is stunning.

All of these together makes for excellent audio, far superior to any standard format ham radio, IF YOU USE A GOOD MIC and take ten minutes to set up the radio.  I am very against the "out of the box" criticism.  If you're too **** **** or lazy to spend 10 min adjusting your radio to match your mic, then you really don't need to talk to anyone.

The 320 is reviewed on eham.   Pay special attention to W6LBV's second review where he did digital audio recordings of his mic collection with no EQ.  

73  W9OY

Dave - W6OVP

It's good to see so many intelligent and well thought out post-adolescent comments on this thread.

Sometimes we sound more like a group of car club elitists intensely concerned with the quality of chrome on the radiator cap. My simple point is if the factory default settings "out of the box" are optimized for the factory supplied microphone "out of the box", this thread as titled would be unnecessary, and the adverse publicity surrounding the topic would disappear.

 Meanwhile, my FLEX 6300 audio with a Heil hand held mike sounds very nice to all who now comment on it.

vincentjlawrence

Resolution: sent the 6300 to flex. They installed ECO 75-1006 at no charge. Now the audio sounds much better with the 500 Hz eq setting at + 1 db, the 1k equalizer setting is only +4db ,(rather than +10db), the 2k slider is at +6 db, 4k at +5 db. Overall tx audio now sounds like me face to face. However , they declined to run the audio to RF test I requested. I will run that later as time permits. Regards to all Vince, N0UA

Steve K9ZW

What is  ECO 75-1006?

73

Steve
K9ZW

vincentjlawrence

Steve

Here is the response I got from FLEX on this issue. Also they did not perform the audio input to RF output analysis I requested. E.g. constant audio input over the voice frequency range with corresponding RF output in 50 Hz steps. However, the rig now sounds greatly improved - more so than the simple description would indicate.
Regards,
Vince

           " Problems / Issues Found:
            The following issues were found during the problem assessment phase of the service request:

              1.. Poor audio reports
            Corrective Action Taken or Service(s) Performed:
            The following corrective actions were performed to resolve the issues noted above.

              1.. Applied ECO 75-1006, for some combinations of low microphone signal and high input gain settings, it is possible that some system noise can be amplified along with the mic signal. Moving the mic circuit reference ground to the audio digitizer clears this noise up. We have performed this simple modification to your radio so you won't have this issue in the future. Note that this modification has no other effect on your audio quality or microphone performance. Also, it works with both Dynamic and Electret mics.
            Note: if required, a full re-calibration of your radio was performed due to the nature of the service performed on your product."

Jim Gilliam

I don't understand the last paragraph. Was a re-calibration required? If so, did they recalibrate?

Jim, k6QE

Steve K9ZW

Hi Vince

ECO suspect is shorthand for something like "Engineering Change Order" or such.  Most likely an  optional change applied only if needed.  If you ask FRS they will certainly decipher the shorthand, as I may have guessed all wrong.

The last sentence that Jim questioned is most likely boilerplate - says that if it needed re-calibration that they did it. 

It isn't surprising they focused on the issue, had a engineered solution, applied that solution, verified performance & checked the radio out, and then shipped it back.  That is what their warranty promise is all about.  Cool stuff!

FRS's benchwork is very fine indeed, and glad you got your radio tweaked to perform!

73

Steve

K9ZW