Hi Edwin, I believe what's being said goes something like this:
-- With a so-called 'flat' response at a wide bandwidth, articulation should be good and the character of the voice should sound natural. So a Heil PR-40 microphone plugged into a 'flat' preamp and amplifier sounds pretty natural and balanced when monitored with good quality headphones or speakers. -- When the bandwidth is restricted (for amateur radio purposes), all of the lopping-off of frequencies occurs at the high frequencies. These are also the frequencies that provide most of the articulation for speech. As a result, the spectral balance is severely disrupted, leaving us with essentially the same lows as before, but lots less of the higher frequencies, so things begin to sound 'muddy' due to a perceived increase in bass, (actually a loss of treble) and articulation suffers. -- Equalization is an attempt to restore balance between low and high frequencies, and in general is achieved by reducing the low frequencies, and increasing the high frequencies, producing a response curve that tilts up as frequency increases. This will always increase articulation, but to further restore a natural spectral balance to the remaining restricted bandwidth requires careful manipulation of levels at specific frequencies within this range. -- As Tim noted in a previous post, some radio manufacturers provide a tilted response to their microphone preamp circuitry, to attempt to compensate for their restricted bandwidth. The problem with that is that not all microphones have a flat response, and in fact some communications microphones have significant peaking deliberately built in. So, a fixed rising response characteristic may work in favor of some microphones, but may be detrimental to other microphones. FlexRadio takes a different approach by maintaining a completely flat response throughout the audio chain, while providing flexible tools (3 and 10 band equalizer, plus adjustable low and high corner frequencies for the filter) to modify the balance to achieve the desired effect. ... at least that's my story, and I'm sticking to it. 73, Dale WA8SRA Edwin Marzan wrote: > Aparently there is a disagreement as to the cause of the muddiness although > the limited bandwidth explanation makes sense to me. So is the cause lack of > articulation or lack of bandwidth? Or a combination of both? eh? > > Edwin MarzanAB2VW > > > > > _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
