It’s going to a battle of phase issues and reflections... so far I have tried the first position and I have the responses and the phase plots... as per usual I have a lovely dip around 850-1k which is the first reflection from the screen and the side window...
I think it’s going to be (as is usual in cars) making the best of the environment we have
currently I have the tweeters as high as they can pretty much go while staying on the baffle on little birch ply steps with the mid 15mm from the bottom of the enclosure... both drivers are on axis with there respective headrest pretty much, it makes the timing of the mid and tweeter on the drivers side approx the same... the tweeter was getting reflection issues to the drivers side window, moving it up and almost behind the pillar to the side window first reflection point
using a combination of all pass filters and normal eq and delay I have been able to match the two sides phase/time plots and got them to pretty much be in phase from start to finish (at most 45 degrees out for narrow bands apart from the big phase ‘flip’ I have due to the reflections
to check it was a side window reflection I added a technical cardboard box and a quick smaart read (with the tweeters off I should add) and the dip came right back up...
There is a pic of the mid low and the tweeter at the very top as high as the 40mm rule will allow... it’s close... but an inch or a mile!