[Elecraft] Phonema Speaker for K3

[Joe Subich, W4TV]

On 2014-09-05 10:53 AM, Wayne Burdick wrote:
 > Every compact (low-profile), non-powered, front-facing speaker I've
 > ever tested with the K3 has fallen short of the K3's own built-in
 > speaker performance at low audio frequencies.

While that may be the case if the K3 is used in isolation, if there is
a shelf above it, the internal K3 speaker is severely crippled.  I am
also *not* a fan of excess bass; I routinely set the 50/100 Hz EQ bands
to -16 dB and set the DSP Low frequency limit to 200 Hz for all modes.
200 Hz is comfortably above the 90 - 100 Hz cutoff for small speakers
and makes audio much easier to understand by eliminating the rumble
that contributes nothing to intelligibility.

 > Front-facing, non-powered speakers the same height as the K3 that
 > sound just as good at the low frequency end may be a theoretical
 > possibility, but I haven't found any yet.

A front facing 3"x5" oval speaker or 3.5" circular speaker in a P3 case 
lined with acoustic damping and a properly sized rear port would most
likely have excellent low-end response.  Add a crossover and feed an
external subwoofer if you really want the low end but be prepared to go
to a powered system instead of passive.

73,

    ... Joe, W4TV


On 2014-09-05 10:53 AM, Wayne Burdick wrote:
> Every compact (low-profile), non-powered, front-facing speaker I've
> ever tested with the K3 has fallen short of the K3's own built-in
> speaker performance at low audio frequencies. The speaker in the top
> cover has the benefit of a very large planar mounting surface. It is
> also very sensitive (95 dB SPL, 1 kHz @ 1 m). Finally, the top-cover
> orientation reinforces sound when the radio is operated near a wall.
>
> External speakers that are relatively tall, such as 8"Hx4Wx4D"
> bookshelf speakers, can perform as well as the internal speaker as
> long as their resonating enclosures are large enough, and/or have
> some sort of acoustic porting to make up for small geometry. But they
> also need good sensitivity if unpowered. They can be very inexpensive
> and look great with the K-Line.
>
> Front-facing, non-powered speakers the same height as the K3 that
> sound just as good at the low frequency end may be a theoretical
> possibility, but I haven't found any yet.
>
> 73, Wayne N6KR
>
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