[Elecraft] K3S vs. K3

[Doug Person via Elecraft]

I have done A/B testing between the K3 and the following radios: Icom 
IC-746, IC-756 (Pro through ProIII) IC-7600, Yaesu FT-450, FTdx-1200, 
FTdx-3000, FT-991, Kenwood TS-480 and an older Kenwood TS-140. In each 
comparison I made sure to adjust all receive settings to flat (no 
emphasis).  For audio input I used a K2 set to minimum output into a 
step-type attenuator. Signal level for each receiver was adjusted to S9 
with no preamps on. In most cases the attenuator was set on. Input into 
the K2 was through an studio quality dynamic microphone that I felt 
confident could produce fairly flat output from 100 to 4000 Hz.  The mic 
was in another room in which I played a recording through my HiFi 
system.  Since the input to the transceivers was always exactly the 
same, the playing field was level.  I did not listen through headphones 
or through any available line out.  I used a variety of small, very 
efficient HiFi speakers.  The FT-450, TS-140, IC-746 all had inferior 
audio quality.  The FT-991 and TS-480 had similar audio quality.  The 
FTdx-1200, FTdx-3000 and IC-7600 all had notably superior audio.  I 
would characterize the FTdx-3000 and IC-7600 as having exceptionally 
good audio. I also used nearly all of the transceivers as a signal 
source for the others, noting a lot of variability in transmit audio 
quality.

I did this just for my own ears - which are well trained.  I do not 
conclude that the K3 has "bad" audio.  But, I do not think it is as good 
as many of the top transceivers today.  For me, good audio is low total 
distortion, flat (but configurable) frequency response - especially 
between 100 and 3000 Hz, even higher when dealing with real ESSB, and 
enough power to push and pull the speaker cone so there is a minimum 
amount of transient or mechanical distortion. (An under-powered 
amplifier for a given speaker, even if not producing high levels of 
distortion, can sound muddy because it lacks sufficient power to move 
the cone "crisply" from one direction to the other "Transient Response").

So, my testing was entirely subjective.  I did it to satisfy my own 
curiosity and not to produce an engineering report for publication. 
However, 55 years as a musician, several years designing loudspeakers 
and HiFi receivers and a lifetime music enthusiast - I think I have good 
ears.  So, again, the K3 does not have "BAD" audio.  But, it could be 
much better than it is.  It is clearly no match for the latest 
generation of upper-end transceivers.

I'm sure someone with the right skills and equipment could do a very 
thorough set of tests.  My personal hope is that the new DSP/Audio board 
will go into the K3 and produce a significant improvement as determined 
by my own ears.

73, Doug -- K0DXV

On 05/16/2015 12:21 PM, Al Lorona wrote:
> I think it goes deeper than this. Long after those engineering changes were made, and even up to the present day, we continually hear complaints about 'bad K3 audio'. Every time the infamous "Bad K3 audio" thread starts up again, I try to understand the problem, but after asking lots of questions the only words I've ever heard used to describe the 'problem' are: 1/ 'bad'2/ 'noisy' or 'hissy'3/ 'fatiguing' Without a better description, preferably with hard measurements to back up the claims, it's almost impossible to help. At this time, I must assume that most reports of 'bad K3 audio' are due to sub-optimal settings of gain, passband, EQ, NR, AFX, etc., unless persuaded otherwise. About five or six years ago I made recordings of various receivers and held a sort of double-blind test to see if the folks on the reflector could identify the K3. (This was in the days before the 4 kHz audio filter fix when everyone was complaining about artifacts.) The results were about what you'd expect from random guessing. I also found it interesting that the ones who were the most vocal about 'bad K3 audio' declined to participate in that little exercise (which included a Kenwood in the set of receivers).
> I also recall one source of 'bad K3 audio' was exacerbated by the (perplexing) modern trend of using headphones with extreme upper and lower frequency response.
> "But my Kenwood sounds great compared to my K3." Yes? And it draws three or four times the current as your K3 -- and weighs two or three times as much. Do you really want to make your K3 into a Kenwood?
> Like Jim, I've spent time both inside the recording booth and as one of the musicians in the studio. I've got fairly good ears. The K3 sounds just fine.
>   Al  W6LX
>
>
>
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