I believe you guys finally got close to the un-obvious possible cause...
If the "1 side only" darker SI images (in my specific setup) were singled to only 1 specific HDSI xducer...then it could possibly indicate a problem with the left SI piezo starting to fail (as you guys mention)...
In the specific case of my setup...2 separate HDSI xducers and the LSS 2 I run ...are consistently darker on the left side...
This is an indication that my unit has a left SI transmitter possibly starting to fail....
"Sonar quiz #7" was offered as a learning tool to help realize all the possibilities in SI images being brighter or darker on 1 side only...
Sometimes this scenario can be duduced down to hardware related issues...
Rickie

