Graphic equaliser tuning

[Howzat]

What's your thoughts?

Just that you should only need 2. I'd imagine the head has 4 out for front and rear speakers. The amp is wired for 1 L&R pair out and 1 sub out but has 4 inputs coming in?
I'd try removing CH3 and 4 inputs OR CH1 and 2 from the amp to see if that makes any difference AND/OR try the Input Mode switch to 2 CH instead of 4.
The sub output side should also have the LF switch activated with a filter of 150 or lower depending on your preference for the subs bass. Not sure why this hasn't already been set during install. I'd leave the other side (fronts) to off (full freq) looking at your speakers.
You may also need to tweak the Input Sensors (gain) for both after making these changes.
I'd also be tempted to do a full reset of the headunit to undo any changes you or the installers may have done to the sound.

 

[CarreraRSR]

Head unit has L/R pre amp outputs for sub, front and rear. Rear has one cable connected so need to understand that cable more. SW and Front has 4 outputs connected which aligns for the 4 inputs to sub

The head unit rear speaker output has been connected to rear speakers in the van directly.

 

[CarreraRSR]

Just had a eureka moment. Found the X-over menu in the head unit. I think these settings may have been reset to default after losing power some months ago. Now having a play….sound instantly sounds more full and 3 dimensional. RTA analysis is showing more mids than I had before. Continuing to play around to ear and RTA so below settings as I found it have moved on already