[Kenwood] Personal Opinion on mikes

[Rick Markey, KN3C]

Jerry, I agree with you on the flat mic concept.  For many years, 
Electrovoice had an engineer by the name of Lou Burroughs who had a 
traveling road show of sorts.  He carried a Nagra reel-to-reel recorder 
with him, lots of clips from various recording sessions, and a handful of 
EV products and literature.  Lou would demonstrate various mic techniques 
and associated problems, and offer up a slew of helpful hints and tricks to 
solve various audio problems.  I saw his presentation twice and learned a 
great deal.

Lou always preached starting with a flat system, and then equalizing if 
necessary to solve a particular problem.  A mic that's not flat, can be the 
source of all sorts of problems.  However, if you know a mic has a response 
anomaly, you can use it to your advantage.  All cardioid dynamics exhibit 
proximity effect.  The closer you get to the mic, the bassier it sounds. 
 If you want to sound like you've got great pipes, crawl up on the mic.  EV 
built mics to eliminate this effect and patented their Variable D design. 
 This proximity effect is why many of the earlier Kenwood mics, in my 
opinion, sound "tubby."

One assumes that the audio section of the HF transmitter has a flat 
response.  That leaves the RF filter to determine the overall frequency 
response of the system.  Hook a flat mic to a flat transceiver, and you 
should get a pretty decent representation of the operator's voice.  But you 
take a mic with a bump in the midrange, and a transceiver with a bump 
somewhere else, and you could end up with a really strange sound!  Just 
listen to the HF bands for numerous examples.

This recent interest in hi-fi SSB is interesting but not necessarily 
helpful.  The hi-fi audio sounds great when I'm in the shack with the 
headphones plugged into my 870.  But when I'm in my van with the TS-50 
connected to my ClearSpeech speaker, the same hi-fi signal is hard to 
understand.  The minute the band gets rough, the hi-fi audio falls by the 
wayside.  Bass doesn't do a darned thing for intelligibility.

Give me a flat mic and about 5 - 10 dB of compression and I think you've 
got a good start toward decent communications quality audio.  Add a little 
high frequency boost and you probably have a very intelligible SSB signal. 


Many may think me a heretic, but you know some of the best SSB 
communication quality audio I've ever heard comes from a D-104 with a 
crystal cartridge, properly matched to the radio.  I say properly matched 
because the crystal D-104 was designed to look into a very high impedance. 
 If you plug that model into a current radio with a lo-Z input, it sounds 
god awful.  The most popular response curve for the D-104 shows a slight 
rolloff at the low end - maybe 2 or 3 dB at 300 Hz, and then a steady rise 
in response starting around 1200 Hz or so.  I D-104 with that curve is 
probably the equivalent of a good flat dynamic with the rig's high boost 
turned on.


de Rick, KN3C