Now that I've begun listening to a wider variety of systems on my TRX-1, I recently experimented with various settings to try to reduce the volume level disparity between different modes, especially the notoroiusly loud P25 Phase 2 talkgroups. This combination of settings worked best for me:
1) Set DAC Gain to minimum (-10db) using EZ Scan (Advanced Features > Receive/PCIF settings tab) or via Global Settings on the TRX-1. This reduces the volume level of all digital objects. Be sure to record your current setting before changing it in case you wish to revert.
2) To compensate for the volume drop in step 1, turn on Audio Boost for all objects in all digital modes EXCEPT P25 Phase 2.
3) Turn on Audio Boost for all analog NFM objects. Leave Audio Boost off for all analog FM and AM objects, including most legacy 800 MHz analog trunking systems (Motorola, EDACS, etc.). While the TRX-1 uses a narrower IF filter when NFM is selected, it does not automatically boost audio output of NFM objects to adjust for reduced deviation.
These changes gave me more consistent volume levels between digital and analog. P25 Phase 2 is still louder than other objects, but the difference is less dramatic and no longer knock me out of my chair. While I leave AGC turned on globally, it seems to have little impact either way.
1) Set DAC Gain to minimum (-10db) using EZ Scan (Advanced Features > Receive/PCIF settings tab) or via Global Settings on the TRX-1. This reduces the volume level of all digital objects. Be sure to record your current setting before changing it in case you wish to revert.
2) To compensate for the volume drop in step 1, turn on Audio Boost for all objects in all digital modes EXCEPT P25 Phase 2.
3) Turn on Audio Boost for all analog NFM objects. Leave Audio Boost off for all analog FM and AM objects, including most legacy 800 MHz analog trunking systems (Motorola, EDACS, etc.). While the TRX-1 uses a narrower IF filter when NFM is selected, it does not automatically boost audio output of NFM objects to adjust for reduced deviation.
These changes gave me more consistent volume levels between digital and analog. P25 Phase 2 is still louder than other objects, but the difference is less dramatic and no longer knock me out of my chair. While I leave AGC turned on globally, it seems to have little impact either way.