"Audio problems"...
Frankly, ALL Jaguars have "audio problems" in the sense that their audio quality is NEVER particulary good. Some are flat out awful sounding.
You CAN improve the audio quality somewhat by carefully removing the speaker from the front housing, applying an X of electrical tape to the front of the speaker, and then reinstalling it. This tames that nasty shrill tone to a respectable extent. Makes it sound almost usable.
One thing that exists in some Jaguar firmware revisions is an FCC menu option with an EQ selection. By default, if this option is in the radio, it's turned on. It puts a DEEP notch into the radio's audio output at 1 KHz. This notch is so severe that 1 KHz alert tones are almost totally inaudible. I don't have a high opinion of "crutch engineering" like this.
Heaven forbid that they could have switched to a newer version of the speaker...one that didn't suck quite so bad.
But the newest radios (most 7100s) do have better audio. It's still not great, but it's better.
The best sounding audio out of any portable radios ever made would be a three-way tie between the original Saber I, the GE M-PD scan or select model, and the Astro Saber. All are excellent. In my opinion.
Elroy