If the frequency you are listening to is narrow band, the lowered deviation will produce quieter audio on any receiver that can't be programmed to compensate for that.
Is there anything that can be programmed on a RS Pro-96 or Uniden BCD-396T to make it sound better? If not what portable radio would you recommend that could programmed for receive-only?
I recommend either an MTS2000 or an Astro Saber. The sound quality is excellent on either of these. Of sourse the Astro Saber will also do digital if flashed accordingly.