I contacted Garmin as to the audio output of the 276, this is the answer I received.
Thank you for your inquiry.
"The audio output can not be adjusted in the unit. This is the specs of the output. The motorcycle cable does not have a pre amp. The audio circuit shall comply with the following:
* 1 kHz sine wave > 900mV RMS
* Output power > 0.1W
* Distortion < 5%
* AMPSUPP > 6.1V with 1 kHz signal present
< 0.02V with no signal present
I will pass on your suggestions for the split map/sounder screen to add the data field though I could see a possible problem with too much clutter with the numbers from the sounder, map and data fields.
Thank you and best Regards,
Stacy Derks
Product Support Specialist
GARMIN International
1200 E. 151st Street
Olathe, KS 66062 USA
http://www.garmin.com/tel. 800/800.1020
913/397.8200
fax. 913/397.0836"