Mike Murdock wrote:
The problem is an impedance mismatch between your MP3 player's output and
the GMA340's music input. This website:

http://www.fremarllc.com/accessories/index.html

has an adapter that will fix the problem and allow you to get full volume.
On the web page, scroll down to "Stereo music impedance adapter"


Well, good grief! Just what did Garmin have in mind for this "music"
input option? Sounds more like a design flaw to me. My PS-Engineering
PMA6000 has the music inputs, and my iPod provides more than enough
volume. Not to mention the fact that I can completely disable the music
muting, if I so desire. Looks like Garmin kind of dropped the ball on
the whole music input idea.

Happy Flying!
Scott Skylane