[TenTec] Audio Problem - off topic

[Jim Brown]

On Mon, 27 Sep 2004 17:23:18 -0700, Rick Williams wrote:

>Is there any add-on device that can be used to take the
>rig audio and shift it up or down a few hundred hertz in an attempt to
>optimize my friend's limited hearing range?

You do NOT want to shift the pitch, you DO want to adjust the frequency 
response to emphasize the highs and de-emphasize the lows. An IF shift can 
do this to some extent and may be enough in some receivers. But the most 
common method is simply to apply audio equalization to the receiver output. 
You want an equalizer, which is simply a high priced word for what are 
essentially fancy and more versatile "tone controls."  

Many pro audio companies make equalizers, and good ones should be pretty 
easy to find on EBay for not a lot of money. One caution though -- look for the 
better units that don't have RF interference problems. One of the better 
companies in this regard is Rane, based near Seattle. One of their  octave 
(good), 2/3 octave (better),or parametric (best) equalizers should work quite 
well.  Tapco is another good mfr, but they didn't make the parametric type.  
Ashley and White are some other good companies. 

Your friend would use these between the audio output and his headphones. 
Unless he has really severe hearing loss, most would probably drive good pro 
headphones directly (he will need to make a simple cable adapter to plug in the 
headphones to the unit's output). If his loss is more severe, he might also want 
to add a headphone amplifier.  Rane and Shure both make good headphone 
amplifiers.  


Jim Brown  K9YC