Severe attenuation of preview audio (but rendered audio is okay)

[Mark Emerson]

I'm experienced with kdenlive, using it off and on for various projects 
over the past decade, always on Linux/Debian. Last time I used it was 
May 2022. I had not upgraded my Linux for several years until July 2022.

Today is my first use of kdenlive after the Linux upgrade, which I see 
(per the About box) was upgraded to 20.12.3. I also checked my kdenlive 
from the Linux command line, and I got a message that I have the newest 
version, 20.12.3-1. However, the kdenlive website lists later versions, 
up to 23.04.0 (2023-04-20)... dunno why my system says I have the 
newest. I tried to re-install but it refused saying I have the newest.

In any event, I recorded a video today with a camera file (MTS) that has 
a low quality audio track. On a separate audio device, I recorded an 
audio file (WAV) from a good lapel microphone. Both files play normally 
with VLC.

When I bring these files into kdenlive, and drag them into track(s) and 
then play, the video displays properly in the monitor. However, the 
audio is BARELY AUDIBLE in both files, even when I maximize my OS 
volume. If I go to Settings/Configure-Kdenlive/Playback and set the 
Preview volume to its max (200%), I can hear a little better and without 
distortion. (If I display the Audio Mixer, and maximize the channel and 
master, it distorts horribly, so I'm not doing that.)

When I render a little zone and play it (forgetting to turn down my OS 
volume), it blares loudly and without distortion. So, the rendered 
result is okay.

It appears that something is severely attenuating the preview/monitor 
volume. Please advise. Thank you.

Mark